Gamma rays Definition and 99 Threads

Homework Statement This is a special relativity question: Two gamma rays of identical energies E collide with an angle \theta between their velocities. Show that positron-electron pair creation is impossible in the limiting case \theta=0. Find the minimum \theta value for p-e creation to...

Hello Guys, I have some questions relating to Cold Fusion / Low Energy Fusion. It seems Gamma Rays are not present from Cold Fusion experiments and Neutrons cannot be seen released from a sonar luminance reaction within the same nanosecond of time as the Alpha Process Completes...

I need to do a presentation to teach the rest of my class about Gamma rays. We need to do some sort of experiment to demonstrate Gamma Rays. Any ideas?

Can a faraday cage be used to stop the radiation at the Japanese reactor? If not why not? I know the frequencty is high but what if you pulsed DC current at the same frequency would that stop it?

It's known that light can have particles characteristic in a particular condition.

Homework Statement The problem is listed as follows: Show that conservation of energy and momentum require at least two gamma rays to e emitted in the annihilation of an electron by a positron. Homework Equations p(initial) = p(final) E(initial) = E(final) Total rest mass = 1.0218...

What would be the best protection from these two at the same time? Lead alone or a mixture of something like lead and Plexiglas?

I read that gamma rays are usually emitted by the nucleus of an atom after it emits an alpha particle, but have been wondering: If the alpha particle being emitted was meant to stabilize the atom, and should have, why does the nucleus need to emit such high energy waves?

Hey I recently did an experiment on the absorption of gamma rays I calculated the thickness and the no. of counts, got a nice exponential curve. So, I used lead as the absorbent or shielding material for gamma... Any suggestions what else I can use for gamma? I thought about sausages or...

Alright, If you had a vacuum chamber and put in a gamma ray producing material (say Radium) would it produce plasma? I have seen someone do this with microwaves, so why wouldn't it work way gamma? Heres the site that uses microwaves to produce plasma...

Here is a question I have for you. Is there a way to stop gamma rays through a dense material that is transparent? If so what is this transparent material? Can someone help?

What CAUSES alpha, beta and gamma rays?

Lots of articles and papers I read talk about the gamma rays produced during fusion reactions. And yet, when I look at equations for fuel cycles, the sum of the energies of the fusion products equals the total energy liberated. Since this implies that all of the energy released in the fusion...

What happens to gamma rays as they travel outward from the core of the sun through the sun? -also, does it take a long time or short time for neutrinos to reach the photosphere of the sun from the core of the sun? Why? The main question has nothing to do with the earth, it is more...

Homework Statement An electron and a positron are moving side by side in the +x direction at 0.50c when they annihilate each other creating two gamma rays. What is the energy of each photon? Homework Equations (mc2 + K+) + (mc2 + K-) = E1 + E2 The Attempt at a Solution I solved...

^ thanks

Homework Statement A gamma ray from 198Au incident normally on a thick aluminum slab travels 1.45 cm before it undergoes a Compton scattering. Calculate the range of angles through which the gamma could scatter and still have at least a 10% probability of re-emerging from the incident slab...

Hi guys, me again, with two questions. Just saw a documentation about supernova, when supernova happens, a huge amount of gamma ray is emitted since it is vacuum in space, why wouldn't the gamma ray hit us? Even if its far and takes a few thousand years for it to reach us, it would eventually...

Does anyone know the speed that gamma rays travel, as a speed or in proportion to the speed of light. Thanks

Hello PF members, I curious to know some basic idea..why the line shape of nuclear decay is displayed as a Breit-Wigner (BW) profile (x-axis as energy and y-axis as intensity) ??.. or any \gamma ray is often shown as a BW profile?? thanks for your reply.

I know that a Hypernova release two huge jets of gamma rays, but I'm not real sure on how they are formed. Also it was mentioned that by following the burst of gamma rays, we're looking back in time. How is this actually possible. I have a shaky grasp on the idea.

I need to know the practical applications of the absorption of gamma rays in materials.

Is there any on-line reference which describes the interaction of high energy (> 100 Mev) gamma rays with matter. These are gamma rays from gamma ray bursts, etc. in contrast to low energy from nuclear radiation.

I remember reading before that hydrogen gas is "transparent" to gamma rays. What does this mean? I know it has something to do with the gamma rays not heating the hydrogen. Also, would Xenon gas be transparent to gamma rays?

what's the difference between gamma rays and x rays?

Hello everybody, actually yesterday i read about an experiment "ATTENUATION OF GAMMA RAYS". can anybody tell me what is meanning of word ATTENUATION.And why we are measuring it? i.e. what is the sigificance of measuring it?

What is the physical process common to both the emissions of atomic x rays and nuclear gamma rays? is it photoelectric.. or the inverse.

Can anyone point to the current state of research about the relationship between antimatter clouds and gamma rays, specifically gamma ray bursts? There was a science.com article quoted in a Yahoo news story. If anyone has read the article, does it say anything pertinent on this question?

How do escape peaks occure? I mean peaks originating from a gamma ray located at the Energy value of \ E_{peak} \equiv E_{gamma}-511KeV. I read that an annihilation process takes place and one of the annihilation photons escapes detection.To arive at detecting an Energy of E_{peak} the...

I don't know if you've heard the latest news from the MAGIC telescope researchers, but they may possibly have come across evidence of Quantum Foam: http://www.universetoday.com/2007/10/03/high-energy-gamma-rays-go-slower-than-the-speed-of-light/ Gamma rays were apparently found to have...

http://www.universetoday.com/2007/10/03/high-energy-gamma-rays-go-slower-than-the-speed-of-light/ Bad news or bad journalism?

Do all types of supernovae emit gamma rays? If so, is it an initial burst, or does the GRB last as long as the visible light? If so, is the GRB in all directions or just in jets? Thanks.

Someone told me that the film badges used in nuclear plants respond to microwave radiation from microwave ovens, as well as to the ionizing radiation they're intended for. I don't understand how this could work. Can someone explain it, or is it just not true?

Hello you guys. I was wondering about the energy limits of the gamma rays. I allready know that the gamma ray spectrum varies from some MeV to 50 MeV (approximately). Does anyone know how can these limits be justified?

IF nothing can escape from a black hole's event horizon, then how do x-rays and Gamma rays escape? and how does it emits light? it says in "Brief History of Time" that the light it emits is just at the boundary of the event horizon. So then how does it escape the gravity and reach earth...

Homework Statement I have a doubt in the following problem. I get an answer which is slightly different from the book answer. 1) A 6 MeV gamma ray is absorbed and dissociates a deuteron into a proton and a neutron. If the neutron makes an angle of 90 degrees with the direction of gamma ray...

Homework Statement Why are gamma rays potentially more dangerous than either alpha particles or beta particles? Homework Equations none The Attempt at a Solution Is it because gamma rays travel more distance before ionising matter so when a gamma ray is fired at you, it could get...

neutrinos are like electrons but not charged. its partner in the subatomic universe. no charge and subsiquently no mass. http://www.ps.uci.edu/~superk/neutrino.html part of the electromagnetic spectrum?? gamma rays are also electrons, no charge and no significant mass. part of the...

How can Gamma rays be used as a projectile ? It need s the nucleus to be extremely unstable.Please give description as well as examples.of such reaction.

Questions, questions, questions... I hope some one can answer these questions. thank you. :) 1. Describe the process of Compton Scattering, explaining carefully how both attenuation and absorption of X-rays occur. 2. How does the process of Compton scattering of X-rays depend on the nature...

Since gamma rays are much more energetic, then shouldn't they travel faster. Gamma rays are light, but since they are faster shouldn't they travel faster than c?

Wasn't quite sure where to post this considering it talks about 2 subjects, but i guess this is a good place to start. My question is: How [if at all] can high energy EM waves affect electronic systems? More specifically gamma rays. I am by no means an electro-physicist, cosmic radiation is...

Am I right in understanding that Gamma Rays can decay into an electron-positron pair without interacting with any matter as indicated by Bubble Chamber results?

can electromagnetic shielding in space protect humans (for a long period) from gamma radiation?? i:rolleyes:

Gamma Rays of wavelength 0.710 Angstrom are scattered in a thin foil of Aluminium. The scattered radiation is observed at an angle of 60 degree from the incident direction. What wavelength would u expect to see? Thanks in advance

Hi, I'm new. I read aboot how an electron, and a positron colliding is supposed to produce two separate gamma rays in completely opposite directions 180 deg away from each other. I understand that the gamma rays are supposed to correspond perfectly to the mass of the particles involved. I am...

X-ray energies increase with atomic number, Z. X-rays originate from photon emissions as electrons drop back into the K and L shells of atoms. Thus they have characteristic wavelengths. Hydrogen has the lowest energy X-rays (Ek=13.6 eV) which is the first ionzation potential. It has one...

some news about the origin of gamma ray bursts, this may be old news to some.there have been many theories for the production of gamma rays, it seems now that the search is narrowing. http://www1.msfc.nasa.gov/NEWSROOM/news/releases/2003/03-041.html Using NASA's Chandra X-ray...

http://www.newscientist.com/news/news.jsp?id=ns99994198