Gamma Definition and 714 Threads

I am interested to simulate a problem in mcnp6, in which gamma rays (energy let say 10 Mev) incident on a aluminum disk and produce electron spectrum which further move in a gas (e.g co2)cell to produce chernkove radiation. Here gamma produce electron and electron further produce chernekov, in...

When I simulate a point isotropic gamma source in mcnp usually number of particle histories to the tally region (let say a detector placed at 30 cm from point source) is much low (few hundreds only) as compared to actually particle histories (1.0E7), Will it be correct if convert isotropic...

Hi, I had the PET scan as an experiment a few weeks ago and then had to write a protocol. The aim of the experiment was to count the number of gamma quanta resulting from pair annihilation. The events were analyzed using the coincidence method. Here is an excerpt from the table including error...

This is what I have for my solution thus far: "For gold to transition to mercury, it must exchange one of it's neutrons for a proton via ##\beta##-decay. In order to find the energy of the emitted gamma rays, we must first find the excess rest energy ##Q## present after the ##\beta##-decay. The...

Hello! i need help in such case. I want to simulate the interaction of gamma photons with only oxygen (O) atoms in MCNP, while am using the material card for silicon dioxide (SiO2). Which card shall I use to get the photon interacted with only the oxygen component separately. Thanks for help.

If Shielding is required for gamma ray flux of 1e23 (let say E=1 Mev). As Shielding cannot fully attenuate flux to zero, how much percentage is technically recommended for shielding of above flux?. So far as I know shield thickness is considered to minimise dose/flux Upto 1/10 of its...

The problem comes with solutions. However, I dont get the 3 steps in the solutions. Why do they calculate decay for 120min in step 3? And why is only the daughter nuclide relevant and no granddaughter? There might be something lacking in my knowledge about nuclear reactions. Also, I don't know...

Hello everyone! I'm trying to replicate phonon density of states (PHDOS) diagrams for some solids using Quantum Espresso. The usual way I do it is the following one: scf calculation at minima (pw.x) Calculation of dynamical matrix in reciprocal space with nq=1 or 2 (ph.x) Calculation of...

I was looking at the gamma radiation data from IAEA's website: (https://www-nds.iaea.org/relnsd/vcharthtml/VChartHTML.html) and was confused by the absolute intensity listed in the page. I Googled it and it seems to be the probability of emission but why it doesn't add up to 100%? For example...

The 1st photo is a Google image of a Gamma ray Burst in space, the image in the other photo is being emitted from a device I am playing around with. I am just wondering what is the cause of or what dictates the behavior of actual Gamma Ray Bursts in space vs whatever light patters are in the...

As there was quite rightly some criticism earlier about not following proper theory, I will first demonstrate what I have understood of the gamma matrices of SU(3). There are 8 gamma matrices that together generate the SU(3) group used in QCD. Gell-Mann used only 2, ##\gamma_3## and...

Astronauts heading towards Mars (and hopefully return) will need protection against the harmful effects of gamma rays in space for this long trip. Apparently, much shorter trips have not caused enough bodily harm to be of much concern. However, a 6-month or longer trip might be a real problem. I...

An example of physical applications for the gamma (or beta) function(s) is http://sces.phys.utk.edu/~moreo/mm08/Riddi.pdf (I refer to the beta function related to the gamma function, not the other functions with this name) The applications in Wikipedia...

Hey all, I was wondering if there was an equivalent closed form expression for ##\Gamma(\frac{1}{2}+ib)## where ##b## is a real number. I came across the following answer...

This pic is from an older text called Tables of Higher Functions (interestingly both in German first then English second) that I jumped at buying from some niche bookstore for $40. Was this hand drawn? I think I’ve seen was it that mathegraphix or something like that linked by @fresh_42...

Hi everyone, I'm making a fuel assembly model and I would like to have a cylindrical gamma source on each fuel rod to measure the decay heat of a fuel assembly but I'm struggling to define the source since it is in a repeated structure. This is the geometry of my model: Level 2 : cells 1, 2 3...

Hello, I am looking for something a bit out of my wheelhouse today, gamma light sources (10 MeV or higher on the max energy threshold). Does anyone here have experience or more information on these machines? Are they typically electron accelerators utilizing a tungsten or tantalum target? I am...

I sent them an email about a week or so ago with the images of the following from the solutions to exercises section 1 of my Insight Article A Path to Fractional Integral Representations of Some Special Functions: 1.9) Use partial fraction decomposition and the Euler limit definition of the...

The statement does not say whether the process is reversible or not, but I suppose the only way to solve the problem is by thinking it actually is. I tried using the formula for reversible adiabatic processes, i.e. PVγ = constant. First, I calculated the initial volume with the ideal gas law...

Gamma is a Minkowski spacetime diagram generator. I probably started this project in August and have been working on it almost full-time since. It will be a free, open-source application. The program can draw all the usual things: axes, grids events, and worldlines, etc. It's easy to create...

Hello All, I am aware of databases which list possible gamma-gamma coincidences for desired isotope. For example: here provides a table at the bottom with all possible gamma-gamma coincidence for Co-60. Question is, are there any similar databases/tables for electron coincidences with...

Hello, I have a few uncertainties about this, Forgive the long questions, I appreciate your time. 1) Why is the maximum energy photon loses during Compton scattering about 0.238MeV (if maximum angle 180 achieved aka backscatter) irrespective of the incoming photon total energy? It seems...

Hello, My question relates to gamma spectroscopy. I understand how the net peak area is calculated for any photopeak. Fortunately, gamma-spec software (e.g., Genie-2000 from Canberra) provides Net peak area and associated uncertainty (for Cs-137 661.7 keV peak, as an example). My question: are...

hi guys I was trying to verify the integral representation of incomplete gamma function in terms of Bessel function, which is represented by $$\gamma(a,x) = x^{\frac{a}{2}}\;\int_{0}^{∞}e^{-t}t^{\frac{a}{2}-1}J_{a}(2\sqrt{xt})dt\;\;a>0$$ i was thinking about taking substitutions in order to...

Some alpha or beta decays produce an excited daughter nucleus, which typically immediately emits one or more gama rays to reach a ground state. This is the case for beta decay of Co-60 or Na-24 for example. While the table of cobalt isotopes on Wikipedia mentions the gamma emission, the one for...

Hi I have a gamma integral in which it is not obvious how I can fix the limits of integration in order to match the standard form of gamma function.I just need someone to tell me how to fix them. I mean the integral number 6 in the picture. You can see my attempt in the PDF .

Well, gamma photons are pure energy, so surely a gamma photon would have the most energy since gamma-ray photons generally have energies greater than 100 keV. An alpha particle has the highest ionising power of the three on account of its mass, it roughly has a kinetic energy of 5 MeV, whereas...

Hi All, I want to ask how to calculate the absolute gamma probability from relative intensities ( found on the tables of nucliedes) following alpha or beta decay. I mean the probabilities that all add to 1. Many thanks.

Hi, Never done much cosmology but reading around I have found several sources saying the early universe (pre roughly 300,000 years) the early universe was full of gamma radiation. Since the universe has expanded this gamma radiation has been red shifted into the microwave region. Other sources...

My attempt at this: From the general result $$\int \frac{d^Dl}{(2\pi)^D} \frac{1}{(l^2+m^2)^n} = \frac{im^{D-2n}}{(4\pi)^{D/2}} \frac{\Gamma(n-D/2)}{\Gamma(n)},$$ we get by setting ##D=4##, ##n=1##, ##m^2=-\sigma^2## $$-\frac{\lambda^4}{M^4}U_S \int\frac{d^4k}{(2\pi)^4} \frac{1}{k^2-\sigma^2} =...

For part b) Gamma is the cavity loss coefficient, L is the length of the rod, R1,2 are the reflectivities. I am not sure how to find the number of ions in the excited state since I don't know the number of ions in the ground state.

hi guys i am kinda have a vogue understanding of the working principle of the gamma spectrometer and have some questions 1 - i need some one to verify my interpretation of the working principle : the sodium iodide crystal emits photons of visible light the intensity of these photons is related...

Both alpha and beta radiations can only travel short distances through air as they're not as penetrating as gamma radiations. How long gamma radiations with 22 MeV energy can travel in air? Is it meters, kilometers, miles, etc. Is there a difference between a lower energy gamma ray and a higher...

According to https://apps.dtic.mil/dtic/tr/fulltext/u2/a351472.pdf the big pulsed power accelerator, HERMES III, generate electron beam with peak energy at 22 MeV and average electron energy at 16 MeV and the resulting photon energy which is bremsstrahlung radiation is approximately 2 MeV...

Some people said if it is originated from electrons then it is X-ray but if it is originated from the nucleus it is Gamma ray. But people can produced X-rays and Gamma rays by Bremsstrahlung process and in Bremsstrahlung process it is resulted from decelerating or braking electrons. So, Gamma...

According to this link https://apps.dtic.mil/dtic/tr/fulltext/u2/a351472.pdf, HERMES III at Sandia National Labs can generate very large area gamma rays by converting the electron beam into bremsstrahlung radiations after hitting the tantalum target. As we can see in the isodose contours in the...

According to https://www.osti.gov/servlets/purl/7234564, the HERMES III which stand for High Energy Radiation Megavolt Electron Source accelerator is "capable of delivering a peak dose of ~100 krad (CaF2) over a useful area of ~1000cm2 (area where dose is greater than 50% of the peak dose) in a...

Hi! Is it possible to construct gamma matrices satisfying the Clifford algebra ##\{\gamma^\mu, \gamma^\nu \} = \eta^{\mu \nu}## that are *real*, for ##\eta = diag(-1,1,1)##? I know that I can construct them in principle from sigma matrices, but I don't know how to construct real gamma...

Hi In the book, "Why does E= mc2" by Cox and Forshaw, while discussing time dilation, the example of a muon is given. The authors explain that muons when circulated in the 14 m diameter AGS facility at Brookhaven at 99.94% of the speed of light, its lifetime is increased from the value of 2.2...

Hi: Source: https://en.wikipedia.org/wiki/Radium Question 1: I think that the first statement suggests that it's the emission of alpha particles, beta particles and gamma rays which raises the temperature of radium sample; possibly on their way out from the sample, those particles and gamma...

I'm typing up answers to the exercises in my Insight article "A Path to Fractional Integral Representations of Some Special Functions", this problem is from section 1 (Gamma/Beta functions). I need a bit of help with this one: The problem statement: 1.9) Use partial fraction decomposition to...

My question and solution that I've tried out are in attachment. Is it true my steps?

I'm not quite sure how to solve the question with two approaches. Let X be the time taken for the cars to arrive. Given that 1 car passes every 2 mins, theta = 2. We are interested in the 10th car that passes so alpha = 10. Thus I know the distribution is Gamma~(theta=2,alpha=10) I can solve...

How to distinguish ##r## and ##\gamma##, ##w## and ##\omega##, ##v## and ##\nu## and ##\upsilon##? They look very similar. Are there some rules that I should use one of them in some specific cases?

Why is it possible for a sigma hyperon to decay into either 2 or 3 gamma hyperons?

I'm watching an episode of "How the universe works" and they explained the nightmare scenario where a star supernovas and turns into a black hole, emitting such a powerful burst of gamma rays, that if it were any closer than 6000 light years then it would be capable of stripping the entire Earth...

So if i had this problem where i am squaring a four momentum vector with itself which gives P2 = (##\gamma mc## )2 - ##\gamma##2## m ##2##\vec v## *##\vec v## I have been told that the gamma factor is not considered at all. why would the gamma factor drop off? Does this rule apply to any...

So using $$L=\frac{mv^2}{2} - \frac{1}{2} m lnx$$ and throwing it into the Euler-L equation I agree with kcrick & OlderDan that we can manipulate this to either $$\frac{d}{dt} m\dot{x} = -\frac{m}{2x}$$ or $$2vdv = -\frac{dx}{x}$$ but I'm not having any epiphanies on how to turn the above into...

What sort of properties would you expect from gamma rays, as you increase their energy, and why? Would they penetrate high Z-matter more easily? What would be the outcome of the interactions? Do you expect photoelectric and Compton scattering processes to become negligible, and the dominant...

I understand the concept that a more energetic photon would cause more ionization events and therefore we can estimate the original energy of the incident photon. But what I don't get is that in practice, you don't get one photon entering the detector at a time, you get a whole bunch of them...