Recent content by Neutroniclad

For the uncertainty about relative atomic mass. Such as for H-1 there is 1.00794(7)u. what exactly does the "7"means? Is it 1.007947? or 1.00794(+/-)0.000007? or something else? ref: http://www.ciaaw.org/pubs/TSAW-2007.pdf

Thank you for your opinion. So you mean the number here refers to the enrichment of Pu-240? i.e. 5%wt means 5% Pu-240 with 95% Pu-239. If so, does 0%wt refers to 100% Pu-239? Or is there something else in the plutonium?

http://ncsp.llnl.gov/ARH-600/files/pdfs/III.A.4-2.pdf For a certain fixed density (let's say 1g/cm3) different enrichment corresponds with different cylinder diameter 20% wt 12.0in 15% wt 11.2in 10% wt 10.4in 5% wt 9.6in 0% wt 8.4in Why the decrease of enrichment result in a smaller...

Does all the signals detected by He-3 detector caused by neutrons? When the He(n,p)t reaction occurs, will proton cause any secondary x-ray photons since it de-accelerates in matter.

"Looking at time behaviour of neutrons in a reactor on time scales of both ~sec and ~days/months Start with fission process e.g. 235U + n -> 236U ->fission Usually divide into 2 Fission Fragments 10%-20% of fission emit a scission neutron (i.e. at time of scission)" I've heard...

It's my fault, I did't mention it's gamma-ray photon until #8

#8 has narrow down the topic to gamma-ray interact with matter, I think

Anyway, thank you guys for answering my question. :)

Actually, I read this description about photoelectric effect from my textbook then I start to think "why not an electron in outer shell? For it's less well bound" Just curious

There are 3 ways that gamma-ray photons interact with matter. One of them is photoelectric absorption, during which, the incident photon conduct all of it's energy to an electron in inner shell of the atom and disappears. The electron absorbed the energy is then able to get rid of the atom...

Because the photoelectron has kinetc energy EK=E(gamma)-E(binding), and the electron in outer shell has less E(binding). I think it supposed to be easier for the incident photon to remove an electron in outer shell.

I am thinking why it is an electron in lower shell being ejected by an incident photon not an electron in higher shell being ejected, since the electron in higher shell has smaller binding energy than electron in lower shell. There is no photon orbiting around the atom.

Since the binding energy of an electron in outer shell is smaller than the binding energy of the electron in inner shell, why the photon kick out the electron orbiting in inner shell? It is always easier to kick out the electron with less binding energy, is it not?

During Internal conversion, the nucleus transfer some energy to an electron in K-shell cause the electron eject out of the atom. After which there left a hole in K-shell then either by releases auger electron or characteristic X-ray the atom de-excited itself. During Electron capture, a proton...