Tritium Phosphorescence: Understanding Electron Capture and Phosphor Changes

[Joseph M. Zias]

TL;DR Summary

tritium beta decays to activate a phosphor - how is phosphor changed.

In a tritium phosphor light, such as a tritium gun site, the tritium activates the phosphor with an ejected electron. What happens to that electron after being captured by the phosphor material. How is the phosphor changed.

 

[davenn]

What happens to that electron after being captured by the phosphor material. How is the phosphor changed.

How is the phosphor changed.

in the long term, it isn't, there is a brief change then it returns to it's pre-excited state

from Wiki

Mechanism[edit]

Radioluminescence occurs when an incoming particle of ionizing radiation collides with an atom or molecule, exciting an orbital electron to a higher energy level. The particle usually comes from the radioactive decay of an atom of a radioisotope, an isotope of an element which is radioactive. The electron then returns to its ground energy level by emitting the extra energy as a photon of light. A chemical that releases light of a particular color when struck by ionizing radiation is called a phosphor. Radioluminescent light sources usually consist of a radioactive substance mixed with, or in proximity to, a phosphor.

 

[Joseph M. Zias]

I understand the activation of the phosphorus atom and its return to its ground state. I was interested in the electron that leaves the tritium to activate the phosphor. Once it enters the phosphor how does it change the phosphor, basically what happens to that electron.

 

[davenn]

I understand the activation of the phosphorus atom and its return to its ground state. I was interested in the electron that leaves the tritium to activate the phosphor

OK

Once it enters the phosphor how does it change the phosphor, basically what happens to that electron.

the electron, or at least it's energy is absorbed and hence the raising of an electron of the phosphor to a higher energy level before it returns to ground state as it releases a photon ( equal ? to the absorbed energy).

@ZapperZ can you help please Dave

 

[ZapperZ]

I don't know much about this device other than what's available to the public. However, isn't this the same mechanism as the phosphor screen for old CRT TVs? How do they handle the charging effects on the phosphor screen there?

From my understanding is that the UV and even fluorescent light emitted by these devices remove the excess electrons from the phosphor layer via the standard photoelectric effect. Also, these tend to not be pure phosphors. I think they are often doped with Cu or some other metals, which may effect their conductivity and allows them to discharge faster.

I think someone else more familiar with such devices should come in and contribute here.

Zz.

 

[Joseph M. Zias]

On a CRT the inside of the tube is coated with a conductive paint, primarily graphite. This coating collects the electrons that hit the phosphor, possible after bouncing off, and returns them to the power supply. Also, some may fly out into the air giving that static you could feel.

I expect there may be some return path in a tritium-phosphor system but I don't know what it is or if there is some other effect going on.