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I am looking for joining research team working on natural radioactivity measurements and applications. Any suggestions are very welcome.
Regards
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I'm interested. We can do a review in NORMs; (Whatever it's type)
Everyone will do a task in it.
Those who are steady can contact with me through the email:
📷
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I just want to extract the experimental data form any source (e.g. NNDC , nuclear data service) in the form of table for any reaction related to exotic nuclei and halo nuclei .if you know any other source to download the experimental data download please help me ?i found some reaction data shown on the website but I don't understand what method i used to collect it .i also adding a screenshot of that site. Help me.
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Well, first what you can try is to click on the X4 or X4+ options that is present in front of that reaction (as I can see there are few publications present in the screenshot). When you click on the X4/X4+ you will be directed to a page that contains all the experimental detail about that reaction and also the measured quantities along with the cross-section presented in a table, possibly at the bottom of the page. You can just copy the data from there and use it at your convenience. I hope this works out for you.
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While reading about the island of stability of superheavy elements[0], experimental approaches and related difficulties[1], an idea has formed in my head. Since I cannot find considerations of such approach in literature or principal physical flaws in it, I’ve decided to ask here.
Disclaimer: Since I’m not a specialist in the field, it’s quite possible that I am simply missing some well known information.
So the question is: Can muons be used for creating new superheavy isotopes near the island of stability?
Some information about contemporary muon beam sources[2], [3].
Consider following variants:
1) The process of muon capture by the nucleus (analog to electron capture, but with muon) becomes the main decay channel for muons in atoms with Z>20.[4], [5]. The resulting nucleus is typically excited to energies in the range of 10–20 MeV[6], because most of the mass energy of the bound muon (-100 MeV) is converted to the kinetic energy of the neutrino. Investigations of muon capture by the nucleus in different materials show, that the fraction of resulting isotopes, which lose excitation without neutron emission is of the order of percent to tens of percent[6], [7]. This suggests that there is hope to use muon capture mechanism for adjusting proton/neutron ratio in desired direction for creating more stable superheavy isotopes. For example, starting from element 117 isotope 294Ts, we can “move” diagonally down-right on p-n diagram https://en.wikipedia.org/wiki/Island_of_stability#/media/File:Island_of_Stability_derived_from_Zagrebaev.svg
Although deexcitation without neutron emission seems unlikely for superheavy nuclei, one-neutron channel (which is the main de-excitation channel) although allows creation of new isotopes (for example 293Lv+µ->292Mc+n).
There are obvious problems: - We don’t know the fraction of neutron-less and single-neutron de-excitation for superheavy isotopes, in best case it will be some percent, and fission will severely decrease the number of surviving nuclei but with facilities like Superheavy Element Factory[8], [9] this might be feasible.
- How to force a single short-living atom to capture a muon. I don’t have expertise to tell if this is very hard or totally impossible for current technology level.
But here we can, for example, align muon beam with ions of superheavy elements while they are flying from magnetic separator to detector.
In this case, we don't have to hit a single atom in a medium, we have to force a highly ionized isotope to catch a charged muon on an orbital. And it can be in vacuum (though I know that current experiment is gas filled). This seems difficult, but not outright crazy.
2) Yet another approach may be using of muonic hydrogen, deuterium and tritium or, maybe even muonic helium, instead of neutrons for irradiating targets and “jump” over short lifetime isotopes, like 258Fm ("fermium gap")[10]. Like in Muon-catalyzed fusion, hydrogen isotope shielded with muon can be used instead of neutron https://en.wikipedia.org/wiki/Muon-catalyzed_fusion For example we can move from long living 257Fm to long living 260Md by capturing a triton.
- I don’t know how feasible is this, but since using thermonuclear explosives[11] was proposed as a way to “jump” Fermium gap...
3) Maybe by synchronizing ion beam with muon beam, we can create by muon capture a beam of radioactive isotopes “on the fly”.
- I highly doubt if this is possible and intensity of the beam will drop by the orders anyway…
[1] V. Zagrebaev, A. Karpov, and W. Greiner, “Future of superheavy element research: Which nuclei could be synthesized within the next few years?,” J. Phys. Conf. Ser., vol. 420, p. 012001, Mar. 2013, doi: 10.1088/1742-6596/420/1/012001.
[2] S. Cook et al., “Delivering the world’s most intense muon beam,” Phys. Rev. Accel. Beams, vol. 20, no. 3, p. 030101, Mar. 2017, doi: 10.1103/PhysRevAccelBeams.20.030101.
[3] MICE collaboration, “Demonstration of cooling by the Muon Ionization Cooling Experiment,” Nature, vol. 578, no. 7793, pp. 53–59, Feb. 2020, doi: 10.1038/s41586-020-1958-9.
[4] I. H. Hashim et al., “Nuclear Isotope Production by Ordinary Muon Capture Reaction,” Nucl. Instrum. Methods Phys. Res. Sect. Accel. Spectrometers Detect. Assoc. Equip., vol. 963, p. 163749, May 2020, doi: 10.1016/j.nima.2020.163749.
[5] K. Nagamine, Introductory muon science. Cambridge ; New York: Cambridge University Press, 2003.
[6] D. F. Measday, “The nuclear physics of muon capture,” Phys. Rep., vol. 354, no. 4–5, pp. 243–409, Nov. 2001, doi: 10.1016/S0370-1573(01)00012-6.
[7] D. F. Measday, T. J. Stocki, R. Alarcon, P. L. Cole, C. Djalali, and F. Umeres, “Comparison of Muon Capture in Light and in Heavy Nuclei,” in AIP Conference Proceedings, 2007, vol. 947, pp. 253–257, doi: 10.1063/1.2813812.
[8] S. Dmitriev, M. Itkis, and Y. Oganessian, “Status and perspectives of the Dubna superheavy element factory,” EPJ Web Conf., vol. 131, p. 08001, 2016, doi: 10.1051/epjconf/201613108001.
[9] Y. T. Oganessian and S. N. Dmitriev, “Synthesis and study of properties of superheavy atoms. Factory of Superheavy Elements,” Russ. Chem. Rev., vol. 85, no. 9, pp. 901–916, Sep. 2016, doi: 10.1070/RCR4607.
[10] V. I. Zagrebaev, A. V. Karpov, I. N. Mishustin, and W. Greiner, “Production of heavy and superheavy neutron-rich nuclei in neutron capture processes,” Phys. Rev. C, vol. 84, no. 4, p. 044617, Oct. 2011, doi: 10.1103/PhysRevC.84.044617.
[11] H. W. Meldner, “Superheavy Element Synthesis,” Phys. Rev. Lett., vol. 28, no. 15, p. 4, 1972.
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I am not a specialist in Nuclear Physics, but your question seems to be very interesting.
I found the following related link * and I hope some specialists will address your inquiry, meanwhile, it is a good research final question for students in atomic physics/modern physics II.
Best Regards.
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I am aware CR-39 (Columbia Resin 39) is mostly used in optical lenses, but I want to use them as ion track detectors. Hence, I need to adquire film-like or sheets of this plastic detector. I have no idea where to buy them! Any information is highly appretiated.
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I am now running a small production line manufacturing various types of CR-39 or PADCs - mostly to custom spec or buy in larger bulk from main manufactures. Worked for TASL for many years and still involved with the track etch technology.
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I am writing my bachelor's thesis about nuclear thermal propulsion and I am trying to figure out, what makes a good neutron reflector.
The obvious, desirable properties of a reflector material are:
  • High neutron scattering cross section
  • Low neutron absorption cross section
  • Resistance against thermal and radiation influences
The same applies to moderator materials. But with a reflector you do not just want to thermalize neutrons, in the best case they are getting reflected back into the reactor core.
So what physical property(ies) describes the capability of a material to reflect (scatter neutrons by roughly 180°) ?
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Dear Felix Richter, please see the references attached to the Russian Wikipedia post on the reflection of neutrons.
https://ru.wikipedia.org/wiki/Отражатель_нейтронов
  • Климов А. Н. Ядерная физика и ядерные реакторы. М. Атомиздат, 1971.
  • Левин В. Е. Ядерная физика и ядерные реакторы. 4-е изд. — М.: Атомиздат, 1979.
  • Петунин В. П. Теплоэнергетика ядерных установок М.: Атомиздат, 1960.
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What are the best suggestions we must take in considerations when we write a review paper in nuclear field?
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This will depend if you are going to talk about the use of nuclear energy for medical, industrial, agriculture or other applications, or you are going to talk about the use of this type of energy source for electricity generation.
In this last case, you should consider, among others, the following issues:
1- Type of reactor to be used and experience of the supplier.
2- Safety of the nuclear reactors to be used.
3- Legal and regulatory matters.
4- Technological infrastructure of the country.
5- Financing of the construction of the power plant,
6- Decommissioning of the reactors.
7- Final disposal of nuclear waste.
8- Workforce qualification and experience.
9- Government support.
10- Capacity of the electrical grid.
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EXFOR contains results of measurement for many targets performed by different authors. How we should this datas analyzed and at the end just one cross-section value for one target is obtained
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Major data evaluation libraries can give this. Still there are disagreements between the libraries. So, evaluation goes on depending the new experimental data.
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Looking at the operational history of our facility, I noticed that last year 43% of the operating time was spent in transient to a stable power level. The log book counts this time as 0w power and therefore does not count it toward burnup. If a 1/3 value of the power level is used to account for the exponential curve, then this value becomes a nearly 20% error in the burnup calculations. I would like to know what has been done in the past to account for this.
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Maybe his was the problem, when I try to match the core excess reactivity vs accumulated burnup trend for MCNPX simulation and recorded operational data. Simulation results show higher core excess compare to the operational data as if the actual accumulated burnup is higher the recorded accumulated burnup data.
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Dear Sirs,
I would like to find out more precisely whether the 2nd Newton law is valid or not in wide range of masses, accelerations, forces. Particulary I have a question whether the inertial property of body (inertial mass) is able to stop the body for small external forces or not. I have found in the Internet the fresh articles with tests of the 2nd Newton law for small accelerations (10^-10), small forces (10^-13) and SMALL masses (about 1 kg). The articles deal with the question of dark matter and MOND theory in astrophysics.
But I am interested in BIG masses. Could the test be carried out in planetary scale? Maybe for the Moon or asteroids? Or for masses like 1000 kg? Thank you very much for any references.
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- When calculating ephemeris in the most accurate models of EPM and in some DE models, only miserable corrections are obtained from the PPN formalism. The Newtonian gravitation remains in the basement of celestial mechanics and of the GR. To my point of view, and stem from the fact, that geodetic lines in the presence of masses get bent, the Newton’s gravitation law suffers from a fundamental flaw due to violation of the inverse square law, underlying it. Let's try to go down from generalizations to specifics.
For example, discussing the modification of the law of Newton, I will argue that the mass is not an invariant, and the APPARENT gravitational mass depends on the distance to the observer Ma = M (1+ KR), where, for particular body, K = const. To verify the validity of the modified law, one will have to a) recalculate the masses of all celestial bodies in accordance with modified law, and b) get the Shapiro amendment, which will also depend on the (apparent) mass. As a result, using appropriate Shapiro delay values, we may get confirmation of the modified law.
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I have already evaluated the elastic scattering cross section using direct reaction model of Fresco and ECIS. Now I need a tool to calculate the Hauser-Feshbach model for the nucleus with A from 4-40. Thank you very much. 
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Nguyen Tri Toan Phuc You can use TALYS1.9(latest version) for alpha induced reactions and EMPIRE3.2(as other people also suggested this) , both the code adopt Hauser-Feshbach formalism for compound nucleus cross-section.For heavy ion induced reaction you can go with PACE-4 and EMPIRE3.2. All these codes are freely available.
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In a recent paper in Foundations of Physics (2014) and Journal of Physics (2015), Mark Davidson tried to explain experimental results associated with Low Energy Nuclear Reaction (LENR) using the off-shell mass theory of Fock-Stueckelberg-Feynman. He also explains some problems with Widom-Larsen's model of LENR.
What do you think? Does such an off-shell mass theory of Stueckelberg remain valid?
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I am calculating Energy spectra (EDX) of emitting charged particles from neutron induced reaction at 14 MeV energy using TALYS nuclear reaction code. How can i compare my calculation of EDX data with the data of ENDF and JENDL data libraries. I think by using NJOY code, one can do so. can anyone let me know how can i access this code and get the EDX data of protons and alpha particles from Tungsten at 14 MeV neutron energy.
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Apparently NJOY is open source see link
Josch
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In the radiation detector especially neutron detector to eliminate the effect of gamma rays the gamma sensitivity is given in terms of Rad/H where as for neutron it is given in terms of nv/cps..
Why it is given like this?
The answer to above will help me a lot.
I will be very much thankful for the reply..
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The idea to mention the gamma radiation sensititvity in Rad/h is applied when neutron tubes are used in a combined neutron and gamma radiation field.
Neutron tubes, typically He3 proportional counter tubes, are somewhat sensitive to gamma radiation as well. If the gamma field is high, then the tube may falsely start to count the gamma's as neutron pulses. The Rad/h indication means that the tube is insensitive for gamma radiation field till that declared value.
This gamma radiation seen by a tube is typically less of energy than a neutron pulse that would be detected by the counter. Some solutions exist to make a tube less gamma sensitive. Suppliers can use special coating, specific less sensitive gazes or a tube base preamplifier with an LLD potentiometer to cut of that low energy part to obtain a neutron tube that is less sensitive to gamma radiation.
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 i want to calculate the number of neutrons producing by an electron linac but i don't find the proper physics reference that can do this:(
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I don't know with GEANT4 but similar simulations were performed using MCNP in the work below.
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The undesired pulses of neutrons or gamma rays are rejected by a discrimination technique based on pulse shape discrimination method.
What is the best system used for discrimination between fast neutron and gamma spectrum?
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Are you looking for a mathematical procedure to remove either neutrons or gammas via the pulse shape technique?
Since you seem to have a system measuring neutrons and gamma rays. I was not talking about about a mono-energetic neutron source.
Regards,
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I want to use the point sources instead of using the standard IAEA radionuclide sources for both the energy and efficiency calibration of the measuring system (HPGe) before the spectra analysis.
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You can download software from website but you must pay for licence to activate it. It is not very expensive. 
I can try to attach Angle,but I am not sure that it is possible to attach .exe file even if it is "hide" as .rar. 
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We expect to be doing experiments with hydrogen-boron fusion using beryllium electrodes and would like to know what chemical reactions we can expect.
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Hi dear Eric.
I think that the temperature is around 600 degrees
Just confirm by clicking on the following links.
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I wish to perform CC calculations using CCFULL for 6Li/7Li. I'm able to include target inelastic states but stuck up while including the projectile ground state spin  and projectile excited states. I'm using the modified version CCFULL2. In which lines of the code should I include the aforementioned couplings?
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There is a special version so-called "ccfull-li" for 6,7Li CC calculations. I think you can download it from Hagino-san's homepage, or you can ask him for the code.
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One can solve the Bateman equation with hypotheses (one group cross sections that were convoluted with the neutron spectrum, main decays, no self shielding and neutron spectrum change during evolution...). Then you can end with a simple differential equation you can calculate by hand.
You may obtain an idea of your composition under irradiation under some assumptions.
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I am in need of field emission miniature electron source of dimension( 1-2 mm diameter emission area and few mm long) which could generate few micro-amp of current at 100-200 V of applied voltage. I know of " cathode.com" which commercially supplies such gun but could someone give me the name of some other company which supplies similar product?
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I have a friend who have suggested me the following companies which supply CNT based field emission source and I hope it could be helpful for others in the field
One can look for following links:
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Using this detector to measure alpha stopping powers.
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I need experimental data from the fission barrier of the super-heavy nuclei with atomic number greater than 117.
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see
"Nuclear Physics A
Volume 944, December 2015, Pages 204–237
Special Issue on Superheavy Elements"
 there you would find your answer
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  • I wish to carry any kind of activation that might be created by Bombardment of Deutron Ions on Metal surface at 300KeV.Is there any software for calculating that?
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By chance, do you mean identifying the materials due to the X-rays induced by low energy deuteron bombardment?
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Hello, dear friends in researchgate. Just as the title says, could a reasonable angular distribution of elastic scattering be obtained in a radioactive ion beam experiment without target-out running? (Low energy nuclear physics)
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In this kind of experiments since the radioactive beam is a secondary beam it comes with all sort of directions and position. You need post-tracking detectors that give you the incident angle of the beam on the target as well as the impact position.
You might need to run without target as a double check that your beam is not hitting any surrounding detectors or target frame. Usually the experimental target for this type of experiment is very thick for statistic reason.
Hope this will help.
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I need your opignions and sugestings about the possibility to found a unified nuclear models betwwen the diferents existing nuclear models. From where we can start.  
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The question is very fundamental for nuclear physics and it is a big area of research as what is done by James Lee Tracy Jr.
I join the idea that liquid drop model in its modern release (by considering some quantum efects) is the most performant one and much convenient to describe nucleus state and on other hand I think that if we look about the time-space dependency of interaction constants (which is a consistent field of fundamental physics), there is a possibility to find a unified model of both weak and strong nuclear interaction but personnaly i don't thing that will be a easy thing to formulate in regular maths...
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 I have used the formula for the distance of the closest approach in the Rutherford scattering. (When this distance is equal to the sum of the radius of the projectile and the radius of the target, the projectile trajectory corresponding to the grazing angle touches the surface of the target nucleus.) But getting the mismatched answers with the literature.
Then I have used another formalism given in the attach pdf but still not getting the same.
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Dear Torilov,
I thought getting the hint student must do some work. You have provided the answer without any work by the student.
v. Kumar
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Metals like copper or silver are never known to emit UV at room temperature. It is now possible by gamma irradiation of metal.
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Dr. Sankaran Ananthanarayanan,  1. YOU ARE POOR IN BASIC RADIATION PHYSICS. 2. YOUR ANSWER LACKS CLARITY AND VERY VAGUE.  I am very sure about my experimental discovery of UV dominant optical emission following Cu or Ag X-rays from within the same excited metal atoms of Variable Energy X-ray Source, AMC 2084, U.K. (Braz. J. Phy., 40, no 1, 38-46,2010)
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332010000100007).  I have already  explained with unprecedented detail how the optical emission takes place in radioisotopes and XRF sources in the same paper.   
FIRST AND BEST REVIEW OF THE RESEARCH PAPER
Margaret West,*a Andrew T. Ellis,b Philip J. Potts,d Christina Streli,c Christine Vanhoof,e Dariusz Wegrzynekf and Peter Wobrauschekc, Atomic spectrometry update-X-ray fluorescence spectrometry, J. Anal. At. Spectrom., 2011, 26, 1919.
DOI: 10.1039/c1ja90038b http://pubs.rsc.org | doi:10.1039/C1JA90038B
Refer under the title: 2.3 Spectrum analysis, matrix correction and calibration procedures
Words of citation: The phenomenon of optical emission predominantly in the UV, which accompanies the emission of X-rays, gamma rays, and beta radiation from radioisotope sources and X-ray tubes was investigated by Rao. It was the first work in which the emission of UV radiation was confirmed experimentally and a possible explanation for the mechanism of the UV emission was given by the author.  https://www.researchgate.net/publication/273124068_24_FIRST_AND_BEST_REVIEW_OF_THE_RESEARCH_PAPER_publis
The reviewers already cited my plausible explanation for UV emission following X-rays. PLEASE NOTE IN MY QUESTION, I DID NOT ASK FOR ALTERNATE EXPLANATION, YET YOU TRIED TO PROVIDE ONE. 
I never came across any reference on what you said, 'photo and Compton electrons exciting valence electron to emit UV'.  And you have not cited any reference, when you said, "(photo and Compton) electrons which, in turn, in favourable cases, can excite the valence electrons to emit UV or visible light.In a particular metal, these are decided by transitions of energy levels allowed  by quantum mechanical rules.  
When I mentioned my work with Cu or Ag X-rays from AMC2084,UK, you provided your own explanation  on gamma rays. Your comment is totally irrelevant and very vague. 
You said, "The line emission spectrum of various elements are available from reference data published by National Standard Laboratories".  What you quoted is optical spectrum of metals at high temperatures.   What I have reported is UV dominant  optical emission from Cu, Ag, and Mo XRF sources and 57-Co  notably at room temperature. Please note radioisotopes and XRF sources emit a new class of atomic spectra of  solids (radioisotopes and  XRF sources) unprecedented at room temperature. If I understand correctly, you are trying to downplay the work done and confuse the readers. In this process, your ignorance of the subject  is exposed.
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The idea is to create a cycle of one irradiation (IRF) followed by a decay (DEC) and to repeat this cycle a hundred times. I noticed the REC, DOL and CON commands, but I didn't find any example or extra information about coding a do-loop. I wish to save and print the calculated results of each IRF and DEC from each cycle.
Note:
ORIGEN2.2 software from Oak Ridge National Laboratory.
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See my article:American Journal of Astronomy and Astrophysics
2014; 2(2): 8-19
Published online October 30, 2014 (http://www.sciencepublishinggroup.com/j/ajaa)
doi: 10.11648/j.ajaa.s.20140202.12
New force, global anisotropy and the changes in b-decay
rate of radioactive elements
Yuriy Alexeevich Baurov1, 2, Yuriy Grigoreyvich Sobolev3, 4, Yuriy Vasilevich Ryabov5
1Closed Joint Stock Company Research Institute of Cosmic Physics, 141070, Moscow Region, Pionerskaya, 4, Korolyov, Russia
2Hotwater Srl, Via Gioberti, 15, I-56024 San Miniato (PI), Italy
3Joint Institute for Nuclear Researches, Moscow Region, Dubna, 141980, Russia
4Nuclear Physics Institute, 250 68 Rez, Prague, Czech Republic
5Institute for Nuclear Research of Russian Academy of Science, 60 – the October Anniversary Prospect, 7a, Moscow 117312, Russia
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Does neutrino/ anti - neutrino annihilation happens ? 
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Dear Rawaa,
to me it seems you have not yet got a proper answer. Let me try to do the job.
For neutrinos to oscillate into anti-neutrinos, both would have to be "the same" particle. How can this be when we call them differently? The answer is that, experimentally, we only observe "left-handed" neutrinos (it's not the perfect name, but left-handed refers to a certain quantum property called chirality), which are those which e.g. are produced in orbital electron capture of atoms or in beta^+ decays, and "right-handed" anti-neutrinos, which are emitted e.g. in beta^- decays.
The reason for this distinction is that the weak interaction only couples to left-handed particles and right-handed anti-particles (that's not 100% precise, but for neutrinos it's perfectly correct). Thus, if "right-handed neutrinos" or "left-handed anti-neutrinos" existed, we would not know about it at least by the experiments we have been able to do so far.
Thus, at the moment, we don't know whether neutrinos are identical to their anti-particles (in which case they would be called "Majorana fermions") or not (in which case they would be called "Dirac fermions"). Up to now, we have observed elementary DIrac fermions in Nature (e.g. the electron has a distinct anti-particle, the positron) and we have also observed non-elementary ("quasi-particle") Majorana fermion-like states in condensed matter systems (in graphene to be precise). However, for neutrinos we don't know at the moment.
What would in any case be needed for neutrinos to be Majorana is "lepton number violation". We are actually searching for reactions which violate lepton number (the most promising being "neutrinoless double beta decay"), but we have found none so far.
From the theory side, we have indications that lepton number is violated, but we don't know for sure without experimental proof:
-We know that neutrinos are massive, and from the theory side, there are many more possibilities for this to happen if the neutrinos are Majorana fermions.
-We know that the Standard Model (SM) itself does *not* conserve lepton number. This is often stated incorrectly in textbooks, because at the perturbative level, the SM does conserve lepton number: it is not possible to write down any SM-Feynman diagram that violates lepton number. However, on the non-perturbative level there are certain types of reactions called "spahlerons" which are known to violate lepton number.
Both these arguments are good motivations to make an experiment to look for lepton number violation, but both do not tell us for sure.
And now we are finally ready to answer your question: *if* neutrinos are identical to anti-neutrinos, *then* we could have oscillations between neutrinos and anti-neutrinos. In fact, such an oscillation is part of one particular Feynman diagram that would transmit neutrinoless double beta decay. This oscillation would be hugely suppressed by the small neutrino mass, making it quite hard to observe experimentally, but in principle it would exist. In fact, even the very first paper on neutrino oscillations by Bruno Pontecorvo studied neutrino/anti-neutrino oscillation - at that time we did not know of more than one neutrino. But we have not found these oscillations experimentally (maybe: yet).
I hope this answers your question.
Best regards,
Alexander
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Nuclear Physics
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It is not just the size of the particle that is used to probe the nucleus but its de Broglie wavelength.  The smaller the de Broglie wavelength, the greater is the resolving power.  To probe the interior of the nucleus, you require a probe with greater resolving power or a probe that can scan smaller and smaller spatial regions.
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My research scope is about the variation of the BSA (Beam Sampling Assembly) angle to determine the time optimization for BNCT (Boron Neutron Capture Therapy). The problem is the coding code of cone transformation. 
Thank you for the help
Best Regard
Buce T
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Hi Buce,
You might be able to use the TRn card to transform the geometry. You could define the cone in (x,z,y) coordinate system and then tilt it according to the angle desired by specifying new coordinates (x',y',z'). You'll have to do a little bit of geometry, but I think that this is the easiest way. 
I recommend looking into Chapter 4, Section II of the MCNP manual.
Hope this helps,
Daniel
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I am looking for collaboration on natural radioactivity measurement and environmental impact
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about the measurement of activity concentrations of primordial (238U, 232Th, 226Ra and 40K) and anthropogenic (137Cs) radionuclide's and gamma dose rate in environmental samples using HPGe and NaI (Tl) dedector.
Natural radioactivity in soil is mainly due to 238U, 40K, 232Th and 226Ra, which causes external and internal radiological hazards due to emission of gamma rays and inhalation of radon ant its daughters (UNSCEAR, 1988). Measurement of external gamma dose due to terrestrial sources is necessary not only due to its contributions to the collective dose but also due to variations of the individual dose related to the pathway. These doses strongly depends on the concentrations of 238U, 232Th, their progenies and 40K, presents in rocks and soil, which in turns depends upon the geology of the regions
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I am performing an analysis on the Atomic Mass Evaluation 2012 and developing a mass prediction formula based on that data. I have made remarkable progress (75% data points within 500keV of AME2012 values) but now am reaching a point where some additional feedback and ideas on the data analysis would be beneficial.  Is anyone interested in opening a dialogue?
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Hi
I am interesting, but how I can be useful
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Self powered neutron detector with Vanadium-51 used to measure thermal neutron flux in our TRIGA MARK II reactor. Another question is, how to determine the conversion factor of current produced by emitted beta in 51V(n, beta)52Cr reaction to neutron flux unit [neutron/cm-2.s-1]?
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Hi Mohamad,
For the first part of the question, I don't think so. The processes are separate, i.e. neutron activation produces V-52, which then beta decays into Cr-52. The answer for the second part is more complicated. One way to determine the "conversion factor" is through Monte Carlo calculations. You will find more information e.g. here: L. Barbot et al., Calculation to Experiment Comparison of SPND Signals in Various Nuclear Reactor Environments and L. Vermeeren, Neutron and Gamma Sensitivities of Self-Powered Detectors: Monte Carlo Modelling (both are conference papers, presented at ANIMMA 2015). Alternatively, you could obtain a "conversion factor" by calibrating the SPND response against activation measurements. However, depending on the SPND design etc., there may be a significant contribution from gamma rays to the total SPND response, and this conversion factor may not be exactly the same throughout the reactor.
Hope this helps,
Vladimir
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According to literature 55Fe decays via electron capture to the 7/2- level of 55Mn (100%). The subsequent gamma decay at 126 keV has an intensity of only 1.3×10-7. However, the vacancy in the atomic shell of 55Fe produces fluorescence gammas with intensities which are several orders of magnitude higher, e.g. Kα1 x ray  at 5.898 keV, I(x ray): 16.2. After electron capture we have at the same time an excited 55Mn and a vacancy in the atomic shell of 55Fe. Why the intensities are so different ? Is it due the internal conversion ?
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According to the decay scheme of NNDC the level 7/2- level at 126-keV is populated only 1.3e-7% of the time and not 100% as you indicate.
Almost 100% of the 55Fe decays directly populate the ground state of 55Mn. So, one would not expect to see many 126-keV transitions.
As an aside the total internal conversion coefficient for a pure M1 of 126 keV in Mn is 0.01652 (see http://bricc.anu.edu.au/index.php) so it does not affect the gamma-ray intensity by much. The lack of 126-keV transitions is simply because the level is not
populated.
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I want to know the density and material fraction of silver-indium-cadmium control rod, and what is the type of nuclear reactor that use this control rod ?
Provide your answer with sources if available, please . 
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Silver-indium-cadmium alloys, generally 80% Ag, 15% In and 5% Cd, are a common control rod material for pressurized water reactors and research reactors. The somewhat different energy absorption regions of the materials make the alloy an excellent neutron absorber. It has good mechanical strength and can be easily fabricated. It must be encased in stainless steel/Ni plating to prevent corrosion in hot water.
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If there is anyone who knows where the experimental setting of Rubbiatron, please let me know. Thanks 
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There have been many (proposed) devices called "Rubiatron" . Some years ago (twenty or more) Rubbia became interested into inertial fusion with heavy ions (I was involved in the design of a part of this machine) then he had an other idea and started to be interested in ADS (people were involved in the design of part of this device) and then he changed his mind...all these were called Rubiatrons.
We are waiting for the next...
All the best
Pino
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Hello everyone,
Please i need  to find Resistivity, transit time  and Gamma ray values of pure organic matter using logging tools
Regards
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Thank you professor
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A method was proposed for measuring macroscopic absorption and scattering cross-sections for thermal neutrons. It is based on a Pu-Be neutron source and He-3 neutron detectors assembly. Beams of neutrons were obtained from the source imbedded in a water tank. Incident neutron beams were above and below Cd cut-off energy. Standard solid and liquid samples characterized with different absorption and scattering cross-sections were prepared. The He-3 detectors oriented inside the sample and at 180 degree , 90 degree and 0degree with respect to the incident neutron beams were used to register neutrons after interaction with samples.  A semi-imperial model describing the detector responses as a function of effective macroscopic cross sections was proposed and successfully fitted the results.
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Well,
I need long irradiation for those reactions whose cross sections are very small.(mb) But for the reactions having  high cross section(b) we dont need to irradiate for a long time. And yes definitely activation foils like Nickel, Zinc, Molybdenum, Ti, Au, In etc  of  different threshold energy are required to monitor the neutron flux.. However we used SULSA to unfold the fast neutron spectrum. Though SULSA demands manual input unlike TALYS/ STAPRE.
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 In an experiment of a radioactive ion beam, which aims at discovering exotic unstable nuclei, a corresponding target-out experiment ( i.e. do the same without target ) is usually proposed. With the help of this procedure, one can define zero-degree line more precisely, and get the angular resolution of the detecting systerm. However, if there is no target-out experiment, the zero-line and the angular resolution will not be so good. So, is there any technique could be used to deal with this case: how to analysis a quasi-elastic scattering of unstable nuclei on light target well without target-out experiment?
 Thanks a lot!
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Maybe I could answer the question if I knew something more about the RIB experiment which I do not find in Google, only this - http://www.seriouseats.com/2009/12/the-food-lab-how-to-cook-roast-a-perfect-prime-rib.html
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Dear friends,
 Hello!
 In a nuclear-physics experiment using RIB, Is it enough to give an elastic-scattering angular distribution using only nearly 1000 events? As this kind of nucleus is really neutron-riched, it is hard to produce an enough amount.
 Thanks!
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Armen Buniatyan is right that it depends on the precision you need. But you can improve the usefulness of your final result by eliminating in advance those Legendre polynomials that cannot contribute to the angular distribution. This can be done by estimating the maximum angular momentum of the incident particle relative to the target nucleus for any given incident momentum in the centre-of-mass coordinate system. To illustrate, suppose the scattering is likely to be limited to s-wave and p-wave scattering (zero and one units of angular momentum), then the scattering data can be fitted by two coefficients only -- yielding two partial cross sections. If the scattering extends also to d-wave, then you have three coefficients and you will derive three partial cross sections, and so forth.
Derek Paul, Professor emeritus, University of Toronto.
.
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Unresolved resonance region (>600eV).
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Visit the home page of the Nuclear Data Section of IAEA and select CINDA, You can search for the requested report in the catalog of the nuclear literature in an interactive way.
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In the calculations of total atomic cross section and total electronic cross section we have to calculate the fraction abundance of each element in our mixture whereas our mixture have a lot of Oxides, and from the total atomic cross section and the total electronic cross section we can calculate the effective atomic number Is it have limits?
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Assuming that you have not altered the isotopic mixture, you should be able to use the standard abundance tables that go with each isotope.  I would use this table, or something very similar.  If you have changed the isotopics using mass-spec or diffusion or something else, then you would need to have measured the abundances.  However, from your question, it looks like you can just use the "natural" abundance fractions:
I think there must also be a NIST table on this as well, which should have exactly the same data, since all of these organizations talk to each other.  http://www.nist.gov/ is a very useful site of standard atomic & nuclear data, and compounds research on these subjects for the past 100 or so years.
Good Luck.  Let me know if you have further questions.
Andrew
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I want to know with more detail why and how beta decay occur
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 Essay on beta decay and theories are attached
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I would like to know the equation related the neutron flux with the fluence rate in nuclear reactors.
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Sorry, but the definition of "Flux" posted by Sathian is incorrect.
Flux has units of particles/unit area/unit time, and is usually written as particles/cm^2/second, or particles/m^2/sec. It measures the flow of "particles" crossing a unit surface per unit time in any direction. In some fields, you can replace "particles" with "energy". It is not defined with reference to "emission", although emission can be measured in flux units if you are so inclined.
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I need the more recent experimental data for (n,p) reaction cross section in tabulated form
(link to any IAEA document or paper)
Thanks
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You can look the following websites, where you need to provide the target, type of reaction and energy information as input.
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Dear all,
I have one question.
When neutrons bombard into Al target, what are possible products?
I did an experiment with Ge spectrometer, and got a spectrum has energy peaks: 2242 keV, 1731 keV, 1368 keV, 846 keV, 510 keV.
When I looked up the internet, I found the possible reactions can be: (http://www.geneseo.edu/nuclear/gamma-ray-spectra)
1. 27Al(n,gamma)28Al        2. 27Al(n,alpha)24Na       3. 27Al(n,p)27Mg
With this reference, I can find energy peaks of 24Na (1368 keV) and 27Mg (846 keV), the other peaks can be the coincidence of these peaks and also annihilation gamma rays.
However, the big question to me is: Where is the peak 1778 keV of 28Al (the cross section is large: 12 barns) ? I cannot find it on my spectrum. Is it something wrong?
In the reference link above, they said that the 1778 keV cannot be detected by HPGe spectrometer but can be detected with NaI spectrometer? Why is it ???
Many thanks for your help.
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Don't know why but only part of my response was 'uploaded' previously.
To continue the higher energy 2754 keV photopeak will produce single and double escape peaks at 2243 and 1732 keV, respectively (your energy calibration might be off a keV or so) and also produces a 511 keV ann' peak. You noted a peak at 846 keV and attributed it to 27Mg. 56Mn emits a photopeak at 846 keV. The main photopeak of 27Mg is at 843 keV, to confirm 27Mg (quite probable) look for the next most intense peak of 27Mg at 1014 keV (if 56Mn then you should see a peak at 1810 and possibly at 2113 keV). 
As noted earlier to properly answer your question one would need to know:
a) the neutron source (e.g., nuclear reactor, D-T, D-D n-generator, isotopic n-source, etc) and
b) the decay time between irr'n and the start of counting (also how long did you count the irradiated Al?)
Finally, off the top of my head the cross-section you listed for the 27Al(n,g)28Al reaction (12 barns) seems rather excessive - I'd check that too.
Hope this helps.  
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I am searching for a database of nuclear levels which contains for each:
  • its own energy and lifetime,
  • energies and branching ratios of gamma transitions.
Of course, this kind of properties can easily be found in NuDat (for example) as pictures format, but I am searching it as an human readable ASCII database to automatically write configuration files in order to generate gamma-decay in Monte-Carlo simulations. So, please can you let me know where I can access to these properties in such format?
Thanks a lot,
Arnaud.
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Hi Arnaud, 
You should definitely use the ENSDF  http://www.nndc.bnl.gov/ensdf/ which is standard database in the feild regularily updated by recently published data. Ideal generator should parse standard ENSDF file. It was claimed that Decay4 http://arxiv.org/abs/nucl-ex/0104018 is able to do this function but one of author has removed the code of generator from the internet.
You can also contact your former boss  Francois Mauger, who is working on new physics decay generator able to take and parse ENSDF file.
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What is the QRPA? How can the energy and radiation probabilities for a specific nuclear level be calculated?
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I may recommend you to read some articles of Prof. T.S. Kosmas. Especially in Nucl.Phys.A829(2009)234–252 you can find a lot of information.
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The interaction of photons with matter such as Compton and Thompson scattering are well-known at higher photon energies. What about the scattering events between photons? Those likely occur at higher energies where the photons resemble to be particles? If it is possible, the cross-section may be extremely low.
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Yes!! Photon-photon scattering is possible. Indeed high-energy photons increase the probability, but the cross-section is extremely low and so a high photon flux is required. An alternative approach is to use low-energy high-intensity lasers, which modify the vacuum in a nonlinear manner leading to photon-photon scattering. I refer you to this article: Nature Photonics 4, 92 - 94 (2010) / doi:10.1038/nphoton.2009.261, with a nice summary here: Nature Photonics 4, 72 - 74 (2010) / doi:10.1038/nphoton.2009.277 .
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Please someone tell me why is there a difference in the path  length of alpha particle in Boron-10 using TRIM and SRIM than the Geant4 Simulation?
The path length of alpha particle with energy 1.47 MeV in Boron-10 is found to be 3.6 micron meters using TRIM and SRIM software.
But when I am simulating in Geant4 the path length is found to be 2.82 micron meter.
In Geant4.10.01 I am using Basic B2 example with QGSP_BERT_HP physics list. I am changing Target material to Boron-10 and particle to neutron.
The target material length is 1 micron meter and radius of target material is also 1 micrometer.I am finding that alpha 1.47 MeV is deposited in 2.82 micron meter of Boron-10 itself.
Why there is a difference in the path length?
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Dimitrios is right when stating that TRIM and GEANT use different methods: SRIM/TRIM applies the semi-empirical model of Ziegler, Biersack and Littmark, whereas GEANT is a Monte-Carlo toolkit using interaction cross-sections that are either directly measured or extrapolated. It is quite usual that the results of the two codes do not fully agree. Typical errors are 10% or even larger.
For your application, the stopping of low energy ions, SRIM/TRIM is usually more accurate than GEANT and less fault-prone. You find details about the SRIM implementation and comparisons to data in the SRIM Textbook by James Ziegler (see first link).
A third method to check your result is the NIST ASTAR webtool that simulates stopping of Alphas in various materials. Just follow the second link.
PS: It don't think you simulated neutrons in GEANT because then the mean range should be much larger than for Alpha-particles.
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High energy astrophysicsts  and Nuclear Physicists
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Rather than answering your question in frequency, it would be more realistic to answer in energy, simply the frequency is so high that gamma ray behave more like a particle (photon) than a wave. The CGRO and other satellite experiment can detect gamma ray only up to several 100s GeV or < 1TeV = 1.E12 eV. Higher than that, the flux is so low that satellite instruments loss detection power or their discrimination power to separate gamma from much higher flux of cosmic rays. The Ground gamma ray telescope can detect gamma photons interaction with atmosphere via indirect measurement. The highest energy of gamma ray  of those experiments can reach approximately 1.E14 eV, in terms of frequency ~ 2.4E28 Hertz.
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Recently, I have referred to many papers about deuterium and tritium retention experience in JET and TFTR. In these papers, it has been most mentioned that D and T have similar behavior in the first wall of Tokamak, such as the ratio of gas
retained to the fuel part, but can we just use these experiments' data to infer the connection between D and T retention behavior?
Is there any theory or study which could explain that?
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The answer is simple and not simple.  Obviously the main part is that they will be similar because the question involves chemistry.  The chemistry of the two are, of course, identical.  What is not identical is the size of the atom  (not much difference, but a small amount).  It also makes a slight difference if they actually react with the W into a deuteride or tritide or via some impurity in the W or if they are just adsorbed onto the surface.  The best solution is to make this a research problem if the small differences are important.
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Consider the MLP where the inputs are discrete but the targets are continual function.
I don't have any mathematical relation between inputs and targets.
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Maybe you need logistic sigmoid function.
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Definition of effective nuclear charge is quite obvious. But, for example, If I take Fe atom and average out all the effective nuclear charge for 1s to 3d , it will give me another number. What will this number signifies ?
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As far as I know, the average nuclear charges need advanced Hartree-Fock solutions. Especially the Ionization Conjecture of the HF theory. The issue is a difficult theme in computational physics. Several related publications could be accessed through Google Scholar and Scopus
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I know that emanation from material such as rooks to the air space or pores between them and exhalation  from this pores to air indoor or outdoor. But as example in Ra-226 source? Emanation? Why? 
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Some authors use emanation and exhalation interchangeably. The correct use is shown in your diagram. Radon in the pores is exhaled by diffusion if there is no movement (convection) of the gas in the pores. Radon is removed by convection if there is movement in the pores, gaps, and cracks in the material. Convection can be caused by temperature differences in the material, water intrusion, or pressure difference caused by movement of air across the surface of the substance or atmospheric pressure changes. Pressure differential in a structure can be caused by air movement (advection) or temperature differentials.
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Espically in Bayesian method or Generalized least square method.
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Hello -
Perhaps if you were to reissue your question in a more data and statistics oriented context, and included regression under the list of topics, you might get more suggestions from the 'statistical community' (where I belong). If you have any releasable data, especially if it could be shown graphically, that might be helpful in any discussion. However, just evaluating data, as discussed for another question under regression, someone (Theo Dijkstra) pointed out, can be misleading, so make sure any advice you get is not spurious, and fits with some theory under your 'subject matter.'
I was encouraged that it appeared that you might have realized that heteroscedasticity may be important. Many statisticians don't remember, or perhaps ever knew that. OLS is dreadfully overused. :-)
Finally, if someone suggests an hypothesis or 'significance' test, another historical accident of statistics, note that a p-value is a function of sample size and can be very misleading if one is used alone. I think it far more useful/practical to look at your regression coefficients and their standard errors - comparatively. But note that if you use multiple regression, that interactions can have some regressors masking others, etc.
Whatever the state of your question now, or any new one, I suggest you reach out to the statistical community, but take whatever you hear 'with a grain of salt.'
Could be fun!
Best wishes - Jim
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what is the important application of radon diffusion in irradiation polymer materials?
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Thank you,  I agree with Prof. Virk,  the radon problem is help human beings to determine the health risks due to radon doses. 
We use polymers to study the effects of alpha radiation or energy in the polymer material to help us in calculating that we want to calculate in our studies.
the same effects of radiation on the polymer may give us an evaluation to what will happen in the living cells such as lungs or stomach .
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Henry constant
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For measuring correctly you need a good calibration before you conduct the measurements.  You must be careful about the leakage of gas from the can or container in which you measure the concentration. 
It is also depends on the procedure of sample collection. 
There is a ratio between indoor radon and Radon releasing from water depending on the radium content in the water.
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we know that the dilution factor in plasma is α=μ/T_p  where μ is chemical potential of plasma and T_p is the temperature of photons.
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Thank you very much dear Mr Behnam Farid.
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It is known that Pauli exclusion principle does not not hold for boson. But there are some recent experiments have been conducted to check whether there is violation of PEP for fermion too. See for instance a paper by J. Marton et al. (2011) on possible test of violation of PEP for electrons. (URL: http://iopscience.iop.org/1742-6596/335/1/012060/pdf/1742-6596_335_1_012060.pdf)
In the context of Neutrosophy Logic, there is a recent paper suggesting that violation of PEP for fermion can be expected, at least in some cases (see file attached).
So, what do you think? Is it possible to detect violation of PEP for fermions too? Has a violation of the Pauli exclusion principle been observed? Your comments are welcome.
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To the best of my understanding, the Pauli principle is a mathematical consequence of what we understand by a Fermion. Whether all particles must be fermions or bosons depends on theory, and perhaps on experiment. But if a particle fails to satisfy the exclusion principle, then it is not a Fermion. Similar comments might apply, say, to attempt to detect deviations from Pythgoras' theorem. A possible violation would mean either that the triangle was not right-angled, or that Geometry was not Euclidean.
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In  general one can obtain specific heat from entropy e.g. c_V = T (dS/dT)_V (partial derivatives of course) etc.  and here  S is the entropy of the Fermi gas.
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For larger Z values the resonance occurs for small neutron energy.
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For certain heavy nucleus the resonance peak position corresponds to a thermal energy because in the nucleus structure, in terms of energy levels, when adding nucleons there are certain positions where the binding energy is significantly low.
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Is there any term exist named "Transfer barrier" for transfer reactions? If yes, then kindly provide me formalism for transfer barrier also.
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Hello!
In low-energy heavy-ion fusion, the term 'Coulomb barrier' commonly refers to the barrier formed by the repulsive 'Coulomb' and the attractive 'nuclear' (nucleus-nucleus) interactions in a central (s-wave) collision. This barrier is frequently called fusion barrier (for light and medium mass heavy-ion systems) or capture barrier (heavy systems). In general, there is a centrifugal component to such a barrier (non central collisions). Experimenters may use the term 'Coulomb barrier' to the nominal value of the 'Coulomb barrier distribution' when either coupled-channel effects operate or (at least) a collision partner is deformed as the barrier features depend on orientation. To my knowledge, the terminology 'transfer barrier' has not been used much. In my view, it could be applied to the transfer of charged particles/clusters.
There is a vast literature on methods for calculating Coulomb barriers. For instance, the double-folding method is broadly used in the low-energy nuclear physics community. Based on this technique, there is a potential called 'Sao-Paulo potential' because it has been developed by theorists in Sao Paulo city in Brazil.
Hope this info is useful.
Cheers,
Alexis
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Currently I am using this formalism, but it is giving me incorrect values compared to available literature.
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Hello!
It can be determined from the quarter-point of the elastic scattering angular distribution. It is the angle where the elastic differential cross section relative to the Coulomb-point (or Rutherford) one is 0.25. This angle relates to the grazing trajectory. The grazing angle can be calculated using the formula for the distance of the closest approach in the Rutherford scattering. When this distance is equal to the sum of the radius of the projectile and the radius of the target, the projectile trajectory corresponding to the grazing angle touches the surface of the target nucleus.
Cheers,
Alexis
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Generally X-ray detectors have only energy information.
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Dear prashanth,
Any detector as such is not designed for giving out only timing or only energy type of signals. The fundamental signal that any detector gives out as a response to radiation interaction in its active volume is a momentary pulse of current. Based on the way in which you process this momentary current pulse the system as a whole either acts as a timing based ( used only for counting purpose) or as a energy signal (used for extracting energy spectrum). My suggestion would be to continue to use whatever detector you have. To get the timing information you can just change the front end electronics from charge sensitive (current integrator) pre-amplifier to a current sensitive(current to voltage converter) pre-amplifier.
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Why is the radium effect measurement by CR39 SSNTDs greater than radium measurement by NaI(TI) gamma spectrometry {the rate (1/10)} in the same water samples?
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Assuming that the proper energy & geometry calibrations were performed for both methods & an adequate sample sizes & count times were used, did you allow for proper ingrowth prior to counting via gamma spec? I suggest waiting for at least 3 weeks after sealing the Marinelli beaker before gamma counting so that the Pb/Bi-214 daughters are in equilibrium with the Ra-226.
If you waited for ingrowth, then I would review all the calibrations-
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Neutrons can't interact with electrons through coulombic force. But both have associated with spin magnetic moment. So is there any kind of interaction possible via these magnetic moment or some other kind of weak interactions?
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NEUTRON DIFFRACTION is used to study the magnetic structure of crystals. It is based on the interaction between the neutron magnetic moment and the magnetic field produced by aligned electrons in the materials.
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Solid salt such as rubidium sulfate is known to emit atomic emission of light only when subjected to high temperatures. Recent study has unfolded that gamma irradiation of the salt can cause atomic emission of light notably at room temperature. What is the technique involved?
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On irradiation of Rb, Ba or Tb salt with gamma rays from 241Am, correspondingly Rb, Ba or Tb X-rays are emitted, as does happen in the case of Variable Energy X-ray Source, AMC2084,U.K.. The latest findings reveal that from within the same excited atoms two more generations of X-rays are produced. X-rays first generate Bharat radiation with energy higher than that of UV at eV level that in turn generates a new class of atomic spectrum of the salt regardless of temperature. The nature of atomic spectrum (percentage of UV, visible (VIS) and near infrared (NIR) radiation intensities in gross light intensity) thus produced depends upon the X-ray energy. In clear words the nature of spectrum does not depend upon the element whether it is Rb, Ba or Tb.
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Rb X-rays are emitted from rubidium sulfate during gamma irradiation from 241Am. Likewise, Cu X-rays are emitted during gamma irradiation of copper metal. Variable Energy X-ray Source AMC2084,U.K. provides these XRF sources.
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So far radioisotopes are known for ionizing radiation emissions such as alpha, beta, gamma, and characteristic X-rays. The question is whether gamma, beta, and characteristic X-ray emissions in radioisotopes cause nonionizing radiation, light ?
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The recent publication in 2010 reported experimental discovery of UV dominant optical emission from radioisotopes (radiochemicals such as 137-Cs, and metal sources like 57-Co). Beta, gamma, and Characteristic X-ray emissions first cause Bharat Radiation (predicted), which in turn causes UV dominant optical emission by valence excitation from within the same excited atoms of radioisotopes by a previously unknown atomic phenomenon, now known as Padmanabha Rao effect.
In 2013, discovery of Bharat Radiation in 12.87 to 31 nm in solar spectrum was reported.
Reference:
M.A. Padmanabha Rao,
UV dominant optical emission newly detected from radioisotopes and XRF sources,
Braz. J. Phy., 40, no 1, 38-46,2010.
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The measured fission lifetime with Crystal Blocking technique and K X-ray measurement resulted in 10-18 sec. But the fission dynamics theory suggests it would be 10-21 sec. To incorporate this large change in lifetime one needs to consider a large damping which would result in uniform angular distribution of fission fragments, but experimental results on quasifission show forward focussing of fission fragments.
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E.Strub
I understand what you are asking that there might be some distribution of fission timescale... But, it is not so.. It has got much deeper implication on the dynamics involved in that time scale... Fission timescale as mentioned by Bohr Wheeler is 10-21 sec which is not verified experimentally, measurements shows only 10-18 sec only, so it raises the question what is happening for 10^3 sec, why it got delayed?
The question is why at all we get 10-18 sec timescale...Do we understand the reason.
It is a much argued topic for decades and it is still not understandable......People bring in viscosity and argue that viscosity increases with temperature which seem quite irrelevant...It require a much better explanation...
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When a K shell X ray is emitted due to transition of electrons from upper states to K shell vacancy, is there any change of electronic wave-function of K shell at the position of the nucleus? Any theory or mode to calculate the change?
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Dr. Ignacio Durian
My question is in the timescale where K shall vacancy still persist and the electron from other shell have not undergo transition to K shell. In the timescale before 10-18 sec, when the vacancy still persists , does the K shell electronic wavefunction at the position of the nucleus is different from filled K shell wavefunction?
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In the context of the Goiânia accident, CsCl is described as showing a blue glow in the dark. Still, there is little explanation to be found in terms of the glow's origin. I have some idea, but I would like to hear your answers first before I share it to get an unbiased result.
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It's Cherenkov Radiation, caused by the beta particles from 137Cs decay passing through the CsCl crystals. The small dimensions of the crystals and the relatively low activity per crystal results in relatively low intensity Cherenkov Radiation, and hence it could only be seen in the dark. In a pool-type nuclear reactor, the much larger volume of the water and the higher beta activity from fission products results in a much more intense Cherenkov emission. I've stood on a small reactor and looked down a view port, and can confirm that Cherenkov radiation is easily visible, and a beautiful site it is too (when you know you are shielded from dangerous levels of ionising radiation - when it's in the open environment and uncontained it would be more worrying than beautiful).