Questions related to Radiation Protection
I want to simulate plasma focus devices with all geometry and surface, with specific filling gas and predict x-ray spectrum.
i want to measure this parameter for estimate x-ray radiation shielding.
please help me for this issue by attach similar code.
i need practice to understand more about this problem.
I'd like to share my experience with our manuscript (theoretical concept) reviewing process. Currently, we are studying radiation shielding materials, particularly glass substances. The effect of different oxides and various glass types is under our scope. In literature, almost all researchers are trying to understand the same scope, as well. However, our recent paper submission was reviewed, and the reviewer concluded that the impact of heavy metal oxides has already been known, and no need to evaluate the manuscript for a possible publication. However, our paper did not only have radiation protection but also physical, mechanical, and optical properties.
What I am trying to ask you all is that this is a fair decision within radiation shielding studies? Is it not the correct way to investigate different glass types, as well as various oxide contributions in terms of theoretical radiation shielding parameters?
Thanks in advance for your valuable comments.
With warm regards.
I am asking about the effectiveness and accuracy of using the film badge dosemeters to record and measure the exposure for the medical staff nowadays as it is a very old way, but it cost nothing to make such a system for developing the films and read it by a densitometer
and the only guidelines that I have to implement such a system is the (IAEA) Safety series NO.8 Vienna 1962 but it is a very old one and can't get any other new versions or similar guidelines, so is there any such recent guidelines
I am recently fabricating some composites for gamma radiation shielding. However, it is hard to achieve a uniform sample since the particles always lie in the bottom even with the dispersing agent. I am wondering is there a big difference in the radiation shielding ability between the uniform and ununiform samples? Is there any equation or theory I can find?
I'd like to ask about the colorization or decolorization of a radiation shielding glass material after exposure to the different energy levels. As far as I see from some literature studies, such kinds of radiation shielding glass materials are affected by the radiation source's dose and exposure time. However, I did not totally understand the mechanism. Actually, is there any concept that predicts these color changes? Or even, color change possibilities against radiation sources?
Hope that I am clear about what I am trying to explain to you all.
The search for alternative radiation shielding glass materials is very popular, nowadays. The literature has a variety of investigations in terms of experimental, theoretical, and simulation. At this point, what will be the next for radiation shielding glass? In a commercial manner, there are some products having PbO content for the intended photon energy level, however, is it possible to produce commercial novel lead-free glass compositions in the near future? What are your opinions?
Currently, I am trying to understand the lead equivalency subject. That is, I have data for my glass series in terms of commonly investigated radiation shielding parameters (i.e. linear attenuation coefficient), and I want to convert this data to lead equivalent thickness. Therefore, is there anyone who can help with this conversion? I can give some data about half-value layer thickness for my glass series as below:
Code-1: 2.60 cm
Code-2: 2.45 cm
Code-3: 2.21 cm
Thanks in advance.
I need to achieve some radiation protection calculation with MCNP6.2 but my partner is using Geant4. Does somebody know a simple way to swap from Geant4 to MCNP6.2?
A comparison between the protection against coronavirus and radiation protection according to the ALARA principle, " The smallest possible exposure time, as far away from other people as possible (or 'as socially distanced as possible'), and wearing a mask whenever possible".
ICRP used critical group concept when assess public dose in the past.
However, recently ICRP replaced critical group concept to representative person concept when assess public dose.
ICRP defined representative person is critical group's average person, but I think these two are very similar term.
What is difference of critical group and representative person in practical appliance?
Let us assume that Betelgeuse is about to go supernova in the next years. To what extent will this affect the dose rate of ionising radiation on ground level on Earth (in orders of magnitude)? How would it affect the dose rate if the gamma-ray burst was directed in the direction of Earth?
Dear Sir/Madam, I invited as a guest editor from high quality journals to handle special issues. If anyone can prepare a review similar to my review papers, particularly about a natural product in cancer prevention with focus on the structure activity relationship and mechanism of action, please kindly let me know to send an official letter. At this stage you should just send the title, authors and affiliation and abstract. Please kindly let me know as soon as you can. The suggested deadline for sending review is about 3 month. Best wishes, Suggeted topic: Genotoxicity of different agents and possble protection. Reducing side effects of radiotherapy and chomotherapy. Next generation of cancer therapy; Natural products. Natural products as novel therapeutic compounds. Radiation protection.
Radiosurgery, the therapy of brain tumors, has long been made using a so called Gamma Knife with high activity sealed sources such as Cobalt-60. Nowadays the therapy can also be made with a linear accelerator such as a Cyber Knife. What are your experiences? Can you share advantages and disadvantages of each system. At the end do you think that the use of radioactive sources is still (medically)justified for radiosurgery given the alternative of a Linear accelerator?
Hello Thai friends! I would like to know how Thailand regulate electronic device radiation both for ionizing and non-ionizing radiation. The following information will be much appreciated:
1. How does the government of Thailand regulate or control electronic product radiation (ionizing and non-ionizing)?
2. What offices/agencies are responsible for such regulations?
3. What are the basis for radiation regulation? (Laws, Acts, etc.)
4. What is the scope of regulation? (Manufacturing? Export/Import? Possession? Use?)
5. What kind/type of devices does the government of Thailand regulate?
4. Are inspection or monitoring activities done as part of regulation? How is this implemented?
Thank you very much!
The ICRP Publication 101 "Assessing Dose of the Representative Person for the Purpose of Radiation Protection of the Public" defines the deterministic and probabilistic approaches to find the dose of the Representative Person from doses incurred by population members. Are results for members of the group of different ages included in forming the average or the 95th percentile of the dose distribution, or shall they be treated separately? I am not sure, although the example for the probabilistic approach in B.7.2 of ICRP 101 would suggest the first case. Simply put, at the end of the analysis, is there only one Representative Person with one Dose to the Representative Person, or are there Representative Persons for each age group, e.g. Representative Infant (1 y), Representative Child (10 y), Representative Adults (adult).
The effect of mobile phone radiation on human health is a subject of interest and study worldwide, as a result of the enormous increase in mobile phone usage throughout the world. Several studies have linked the radiations to cancer using animal models like rats. How can we prevent this, if true?
- radioactive sources
- thickness need
- risk assessment
- build up factor
- effective atomic number
Hello every one i want to simulate the different modes of heat transfer through cement Kiln. Conductive heat transfer from clinker to inside wall of cement kiln .Convective heat transfer to outside air from cement kiln and radioactive heat transfer from the cement kiln surface. I want to enquirer which ansys module should be most relevant in modelling clinker geometry and and such modes of heat transfer.
I had tried ansys fluent for and steady state thermal module but not sure which one is more releavant
Collective dose is defined in the ICRP Draft TG 79 report as the dose integrated over an interval for a set amount of time and for all individuals affected. Collective dose is intended for operational planning. The draft clearly proscribes use of collective dose for risk assessment and assigning detriment to a population. Collective dose requires the linear no-threshold risk model with no distinction for radiation type, internal or external, and dose rate.
The purpose of collective dose is for optiimization of radiation protection. Optimization is for total dose to a group, while radiation protection is for individuals. Is collective dose and optimization useful in your radiation program or is simply another regulatory hoop to jump through. Please give examples.
For All depleted uranium slabs, the beta dose rate at contact is 240 mR/hour. Any mathematical derivation or reason if you know. Please share.
I have used a radiameter which displays results in micro-sievert per hour in order to measure leakage radiation dose around jaws and I have obtained a value of 40 micro-sievert per hour just after finishing patient radiotherapy treatment. My question is what's the threshold value in which there is a potential radiation leakage problem.
Does magnetic field can heat the human body?
According to the International Commission on Non-Ionizing Radiation protection (ICNIRP), there is a maximum allowable magnetic field exposure to our body. I don't understand why magnetic field can be harmful to our body. I understand that electric field can heat our body by ionic polarization and dipole rotation of an atom or molecules. Whereas, magnetic field can only heat magnetic materials.
Although the principles and safety regulations for radiation protection in general is the same as when applied for dentistry specific. However, the applications in dentistry is very unique to a certain extend. I would love to see that the dental world and the medical worlds collaborate to a greater extend in this regard. I am of the opinion that most oral health care workers needs to improve their knowledge, attitudes and practices in this regard.
I would like to know what are the measuring instruments used by physicist in nuclear medicine in order to perform some tasks as imaging quality assurance, equipments quality assurance, radiation protection, .....
X-ray with energy of 40-100 kVp is radiated to shields with thickness of 1mm(shape of sample is sphere with radius of 10 Cm). Distance of source from detector is 100cm.
Schematic set-up of X-ray attenuation property measurement;
We want to buy an underwater detector for radiation protection purpose. Differentiating between natural (like radon and thoron) and artificial (like iodine and cesium) radio-nuclides is of more important in this project. We just want to buy one detector to do some test and get familiar with. After verification we plan to deploy a network in the sea. So currently I need no accessory or central server, I just need a stand alone device which I can communicate with a laptop.
I checked out AT6104DM(atomex), sara water(envinet) and Katerina. I contacted with the companies. Now for financial purpose I need to know price of them.
If any body has bought one of these devices or similar, kindly give me a clue about the price of them.
Also a training course by experts of company would be useful, Can you guess how does it cost?
I need this book or any recent copy of it, or any reference have the relation of calculating the absorbed gamma dose (D= Γ x A /d2) or any other dose.
the book: F. H. Attix, "Introduction to Radiological Physics and Radiation Dosimetry," New York, John Willy & Sons, (1986).
For whole body monitoring thermo luminescence TL, OSL Film RPL etc are used at chest level or so. Of which material phosphor your dosimeter is made and what is frequency of use?
What does it measure Hp(x)?
What type of radiations it can measure other than photons?
Area of human body is mass/age dependent. In Radiation Protection, it can (area ) in general be used to convert skin dose to whole body dose in case of non-uniform (shallow) exposure or if some portion of skin receives shallow dose. What are mathematical models which can be used to estimate are area?
A lead shielding (µ=1.19) is used to protection against a source of caesium 157 with dose rate of 0.11 R/h. emitted gamma radiation has a 0.6 Mev energy. If lead shielding thickness is 0.02 m, what will the permissible exposure time (stay time)?
I'm currently working with plants but I have a bigger interest in Astrobiology. I'm looking for someone who works in both areas or that is interested in this. I thought about a project to study radiation protection using medicinal plants. Can anyone help me?
ICRP has continuously decreased dose limit from 150 mSv to 50mSv to 20 mSv per year in past. This was based on various studies mainly data of atomic bomb survivors. Since the risk information is almost complete from the study of atomic bomb survivors it is less likely that present risk factor of 5%/Sv is going to change. In view of this what could be the future changes in annual (average) dose limit of 20mSv . Will ICRP make it 10 or 30 mSv after 2035 or so?
Are you measuring low energies from Electromagnetic waves emitted by human body and measuring high energy gamma rays emitted from radionuclides in the human body. Did you identify the radionuclides? Does it vary with age? Body weight? Geographical location? Race, ethnicity, religion, diet, etc.?
I admire your research. I consider it very important. I have some general questions:
The DNA damage of lymphocytes conclude to cancer?
How do you measure the DNA damage?
The exposure to low-dose radiation from the uranium mining is more dangerous for children or the age does not matter? I know a city that is close to a lignite mine and many children have leukemia.
I am looking for an appropriate FDG PET SUVmax threshold to use. Can anybody provide me with some ideas?
My question concerns charcoal conditioned in Ukraine from the hardwood (oak and horn). In the "Specifications", it is described as having a Radionuclides (Radioactivity) - max 400 Bq / kg. I have not idea about the existence of any norms. I tried to find out on the IAEA site but found no data on the subject.
Due to the interaction of such radiation with matter, a small charge will be formed on the material surface. This charge must be safely leak out; therefore such shielding material must have good electrical properties.
1. Can someone tell me, why there is no radiation emit from Helmholtz experiment? Is that because of low voltage? Can it produce the X-ray if this conduct this experiment with high voltage? Say 30 kV?
1.a. The electrons is interact with the glass (Pyrex glass),
2. In X-Ray Tube, in order for electrons to escape into the partial vacuum, high voltage and heat are needed.
o High Voltage: To accelerate the electrons
o Heat (Filament): To emit the electrons by thermionic emission
o High Current: To produce more electron hence the intensity will become higher (more electron means more count). That why in XRD application, if the intensity from the diffractogram is not high (within noise border), we can increase the mA to get the exact intensity and peak.
Correct me if I’m wrong.
3. In FESEM, Electron Gun, the same concept was used, however, the Primary Electron Beam does not interact with the target material, for example, Titanium, Tungsten, Copper, etc. However, the Xray only can be produced if the beam is hitting the sample in the chamber. Is that correct?
4. All in all, the Xray only can be produced, if the medium is high vacuum, high voltage, heat (filament), and the electron must need to interact with matter?
This question addresses specific issues associated with development of shielding optimization methodologies to accurately evaluate radiation protection strategies while accounting for the inherent multiple uncertainties associated with the problem. For most shield design efforts, effective dose for specific GCR or SPE radiation design environments has been calculated in order to determine the effectiveness of different shielding configurations to meet specfic vehicle radiation requirements.
NOTE: Question is related to shielding approaches of Spacecraft in Space .
According to my theory on cell response to radiation exposure, I got a weird simulation result of cell survival fraction curve. It is not like the traditional exponential-like curve, instead, it has a surprising lower region within a sort of exponential-like curve.
Is there anybody actually has ever observed cell survival fraction curve in actual radiation biology experiment like this one?
Some basic simulation information as below:
The dose listed in the figure was the total dose, but it is accumulated dose in 7 days.
Reading this paper about the metabolic fate of chondroitin sulfate, where 24% of "Administered radioactivity" ends up in feces after 24h of administration
Single dose in rats of 16 mg/kg and 90 Fci/kg, activity of 12.5 mci/mg,
3H-chondroitin sulfate (3H-CS) was prepared by reduction with sodium 3H-borohydride.
I've never taken any radioactivity/physics courses in my degree, so Im lost on how to determine the actual concentration that they found in the feces in a molarity or w/v form. Could anyone help me understand the calculations I have to do?
Paper in question: http://www.vitaflex.com/res_af401a.php
There are several material which light in weight and transparent also they won't allow cosmic radiation to penetrate to it. I'm looking for that kind of material.
There are many kinds of research going on the topic of radiation shielding for sustainable Human habitat in space. This is one of the important factors for the sustainable human life in space. So I have a doubt on choosing a suitable material for radiation shielding in outer space habitat which should protect human from both solar and cosmic radiation.
Consider a solid sphere of some material and a spherical shell of the same material with both having the same thickness in the sense that a straight-line path from outside to the center travels through the same thickness of material. These are intended to be used as radiation shields in a given external electron environment. The interest here is the ionizing radiation dose at the center of each. Because electrons do not follow straight-line paths when going through a shield, I am not surprised that the solid sphere and spherical shell will not produce identical doses at the center, but how much different should they be? And why? Is there some simple analytical argument (not Monte Carlo) that can roughly account for this difference?
Dear colleagues. One contaminated herself with final [18F]FDG product. Hand-Foot monitor with plastic scintillator coated with ZnS shows 7kcps alpha contamination. I have doubts that there was alpha particles. Detector is covered with thick plastic wrap foil and 18F should be pure. It was obtained in 18O(p,n)18F reaction after purification on several cartriges. Is that alpha detection a false positive result? Is it possible that monitors pulse discriminator or high voltage on PMT is badly configured ?
Assume that we would like to "measure" the background radiation level (e.g. dose rate), but we have a low radioactive source or a well-shielded medium source in the area/room. If we subtract the estimated/calculated dose rate given by such sources from the actual measured values, can we call the final result a "measured" value? or because we did some calculations (in this case, simple subtraction) on the values they cannot be considered as measured anymore?
The methods of Partitioning and Transmutation (P & T) of spent nuclear fuel from Nuclear power plants are currently under research and development. Partitioning aims at Separation of the fuel in uranium, the actinide Plutonium (Pu), Neptunium (Np), Americium (Am) and Curium (Cm) and the fission and activation products, Transmutation on the conversion of Plutonium and of the minor actinides Neptunium, Americium and Curium in short-lived fission products. These methods provide the possibility that not only the total activity in the final repository for heat-generating waste decreases over time faster, but also their radiotoxicity.
I am conducting a radiation dose exposure and risk assessment on native peoples in the USA and several other countries. I am interested to learn if anyone has been reporting low dose results and in particular in relation to indigenous peoples.
I completed a construction of Radiation Shielding Concrete (basement and semi-basement) for Oncology treatment ( LINAC, Cyclotron and Cyberknife). I'd like to set guidelines and/or recommendations for future use of the facility.
Concrete - density is maintained 2.5 gm/cc, slump < 75
CA - 2/3 in and 1/2 in stone chips
Cement - PPC
Ice was introduced to reduce hydration temperature
Some patients with head and neck cancers treated by radiotherapy with or without chemotherapy presents with an unacceptable morbidity of severe dry mouth, severe mucositis and, extreme toxicity to the neck skin, whereas, in some patient’s this does not happen with the same dosage and technique. This often leads to treatment interruption in many cases. So, it will be of interest to know and predict which patients are likely to develop these side effects of radiotherapy and thus, we can help improve the quality of life of patients by a predictive method.
What life style behaviors and biologic parameters that should be included to predict the risk of extreme radiation toxicity in patients receiving radiotherapy for head and neck cancers ?
Particularly I am interested in threshold values for 226Ra, 232Th and 40K activities in nitrogen, phosphorus and potassium fertilizers.
Any input is highly appreciated.
OR, does the use of these radionuclide tracers, themselves, add a significant risk of causing cancer in patients?
The dose of ionizing-radiation from the tracer used in one PET scan, for example, typically exposes the patient to about 25% of the maximum allowable annual radiation exposure permitted for nuclear workers (which is a VERY high limit = to over 200 standard/modern medical chest xrays, meaning a patient is getting exposed to the equivalent of about 50x chest xrays ALL AT ONCE for each PET test).
We have small diffusion chambers from aluminum, inside this chamber a Ra-226 source is installed with a normal emanation coefficient. Do we need to isolate this box with a roof using a good isolation glue?
In radiation dosimetry for acceptance test of computed tomography; papers speaking about ' CTDI ' more than 'MSAD' ;
seem that MSAD is theoretical concept but maybe accurate than other index to estimation of dose in QC.
How be measured this index in practice?
Thanks in advance
Why is it better than micro-nano-materials in low-energy photon is absorbed, but the size effect disappears with increasing energy?
I am planning to conduct FMEA study for some of the existing equipment/device.This device has several models, most of them have almost same design features. I wish to find out the weak parts/sub component of these device type by conducting the study.
Since number of different models of this device are available in the market, it is not possible to conduct study on all the models.
Whether it would be appropriate to conduct FMEA study on specific model and conclude the results for the whole species of the devices?
PPC cement, coarse aggregate ( mixture of 3/4 th inch & 1/2 inch downgraded stone chips), fine aggregate (coarse sand), and admixture (MasterPolyheed) is used for this construction.
Fresh density is kept above 2.4 gm per cc. The hardened density requirement is above 2.35 gm per cc.
Ice is being used to decrease the mixing water temperature. (To avoid hairline crack in the future)
Key concern is to avoid radiation leakage.
The rooms are being constructed in the basement with wall thickness of 5 to 8 feet and slab thickness of 4 to 8.5 feet. Rooms will be used for Oncology treatment and/or Tomotherapy.
Is there any data available for potential exposure (#unexpected exposure) in the occupation of radiation facilities( non-nuclear facilities) like industrial radiography, food irradiation facility, radiotherapy etc.
I want to compare my data with some of the study resulting in the probability of potential exposure in above facilities. OR please give reference for the data for probability of accident in above facilities.