Nuclear Structure - Science topic

Nuclear structure

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…

[0] https://en.wikipedia.org/wiki/Island_of_stability

[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.

As this is my first year in post graduation working on Nuclear Shell Model, reading articles such as "The shell model as a unified view of nuclear structure" by E. Caurier et al. REVIEWS OF MODERN PHYSICS, VOLUME 77, APRIL 2005, makes me facing many subtleties to recognize. Kindly, if there are resources (articles, books) to remake my background, it would be appreciated.

its atomic number is not too high. So what kind of mathematical or physical constraint on its nuclear structure breaks it so easily? Why doesn't it have any natural stable isotope?

If it's one isotope with nearly equal neutron and proton number be produced, why that would not be stable?

For any expected quadrupole deformation value; what are the values to be set for deformation of the h.o. basis and deformation of the initial W.S. potential in the code? should they set to the same value of the expected beta value?

The shell model treats the motion of nucleons within the nucleus as non-relativistic; I'm looking for models that treat the motion of nucleons as relativistic.

We want to calculate the heat loads on the divertor and estimate the results.

I want to determine the cellular localization of a protein, hence looking for a protocol to fractionate cell extracts, i.e. cytoplasmic, soluble nuclear extract and chromatin bound fraction. I have been using CSK buffer with 0.1% Triton-X but I'm not sure if it's stringent enough to distinguish between the two possibilities of being bound to chromatin and associated with some other nuclear structure. 

Hello everyone

Does one of you ever tried to vizualize RNAs by immunofluorescence? I have tried an RNAse treatment to check the integrity of some nuclear structures but I am unable to find a way to show that my RNAse indeed enter the cells to degrade the RNA.

Thank you very much

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?

Hello everybody,

I'm interested to understand about the effects of isotopes on properties of a molecule. For example in hydrogen, helium or oxygen (which have isotopes) what is the general expectation on some properties like critical temperature, critical pressure, critical volume and normal boiling point and ideal liquid density of isotopes?

I mean as an example is it true to say that we should expect higher value in volume and density in heavier isotopes? or higher normal boiling point in heavier isotopes like D₂ rather than H₂?

As an example the normal boiling point of ¹⁶O¹⁶O is -182.95 C, is it true to consider the normal boiling point of ¹⁶O¹⁸O (which is heavier) a value like -182.5 C?

So if I conclude my question, what is the value of heavier isotopes against lighter isotopes in following properties: (answer by bigger or lower):

Normal boiling point?

Ideal liquid density?

Critical temperature?

Critical Pressure?

Critical volume?

and Acentric factor?

Thanks in advance.

Meysam.

...

Hello, every friend! 

I know that B(E1) spectrum can be obtained by using virtual photon method, experimentally. But how do you get it through any theory approach? Is there any code to do that?

Many thanks!

what is meant by the band termination for particular given Nucleus let say ⁵²Cr?

I am making nuclear and cytoplasmic fractions and I need to assess if it is working. I see that some use Histone H3 as a nuclear marker/control, what antibody would you recommend?

Recently we have synthesized some perovskite oxide structures which crystallize in Pnma space group at room temperature and low temperature. The reported magnetic space group is also same as nuclear structure for such kind of materials. However there are some misfits in peaks, Moreover some peaks are missing. I want to refine magnetic structure carefully. But I do not know how to do this scientifically. Can anyone help me how to do this?

Any information for proton pickup reaction data for the 151,153 Eu isotopes, with 152,154 Gd isotopes as a target?

Nphmax,mult, pair ,ell,qq,chq,oct,bfe,bfq ,bfm ,chi ,beta,betad,bfqj,bfmj, ippar1,ippar2,ippi, ippm , ilev,iai ,iam, neig , pen , vsq and ipr

Is it possible to find the geologic time of an original nucleus (radioactive-parent) based on the given:

Half life of the original nuclei.

Activity, half life, decay constant, nuclei of the Radiogenic (daughter).

Assumption:ß0

The parent is unstable while daughter is stable.

A hydrogen nucleus consists of a single proton. A 2-hydrogen (deuterium) nucleus consists of a proton and a neutron. A tritium nucleus consists of a proton and two neutrons.

This makes me wonder how an atomic nucleus made of a proton and a "minus one neutron" would look like, and the closest thing to a "minus one neutron" I can imagine is an antineutron.

If the proton and antineutron annihilate, is it still possible that the thing they annihilate to remains somehow stable enough to behave like an atomic nucleus?

are they same. If yes then all excited bands are side bands in nuclei.

What is vibrational enhancement factor and how the vibrational energy levels come into play in Nilsson and Cranked Nilsson models

I'm doing my undergraduate research now on macrophages (RAW264.7) and microglia (Bv2). Just recently I realised that some macrophages, after long time of LPS stimulation, have acquired a star-shaped morphology. I first though they were undergoing cell division in prophase cause the star-shape looks like some packed chromatins being anchored in the centre and radiating outwards, but I couldn't be sure of that cause macrophages don't really divide under stress. However, i'm not sure if they're dying by necrosis either because I haven't found any paper that describe cells having exactly the same shape during LPS or other types of stimulation. As I am working on finding ion channels on the nuclear envelope with immunofluorescence, those star-shaped nuclei haven't any antibody stainings colocalising with DAPI.

So has anyone ever seen such star-shaped nucleus in macrophages or any other cell types? And does anyone know what is going on in these cells?

Thanks in advance!

What is the average energy of the light fragments (neutrons, protons, alpha etc.) produced in multifragmentation reactions?

What is the average multiplicities?

What is the common yields of the multifragmentation reactions?

In coordinate space it is the limit the ratio of the radial function for l=2 to that of l=0 as r goes to infinity. I'm hoping there is a similar formalism in momentum space. If so, I'd appreciate it if some one can direct me to a relevant paper or so.

Is there any term exist named "Transfer barrier" for transfer reactions? If yes, then kindly provide me formalism for transfer barrier also.

Currently I am using this formalism, but it is giving me incorrect values compared to available literature.

For example: for Nd electric quadrupole moment is -0.78.

I have performed the theoretical calculations for finding the island of stability at superheavy valley. Here, we have used relativistic mean field (RMF) and Skyrme

Hartree Fock (SHF) with various forces for these calculation. Based on the average pairing gap for proton and neutron, nucleon separation energy, paring energy, shell correction energy and single particle energy for nucleons, we have predicted Z=120

with N=182/184 as nest magic number after Pb. Here, I like to know, is there any other observable for strengthen our predictions.

I want to calculate the magnetic moments according to shell model for the first excited state in 24Mg

For the last few years, I have been using relativistic mean field theory for determination

of clustering in atomic nuclei. The method of determining the cluster is directly

connected with the density distribution of the nucleus, which obtains from the

relativistic mean field theory. The counter plotting of these densities gives a

clear picture of clusters inside the nucleus.

I want practical thesis for work it out. E.g modified fuel rod.

Why 2 neutron and 2 proton should combine in nucleus and decay by alpha? They can decay as n and p itself.

Can anyone help me in find energy values required for the nuclear fusion of some light elements of the periodic table, example: N+N -> CO?