Gamma radiation photoelectric effect

Click For Summary

Discussion Overview

The discussion centers around the photoelectric effect and its relation to gamma radiation, particularly why gamma radiation is not utilized for energy capture despite its higher energy compared to other forms of electromagnetic radiation. The scope includes theoretical considerations of the photoelectric effect, practical applications, and the challenges associated with gamma radiation.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes the photoelectric effect as the process where electromagnetic radiation overcomes an electron's binding energy to generate electricity, as seen in solar panels.
  • Another participant points out that gamma rays are both dangerous and rare, making sunlight a more practical energy source.
  • A further contribution suggests that calculating the energy output from a radioactive source like Cobalt-60 would reveal the low wattage produced, despite the high energy of gamma radiation.
  • Another participant clarifies that the photoelectric effect typically involves light interacting with metallic surfaces, emphasizing that gamma rays interact differently, often affecting core-level energy states or even the nucleus, which complicates the expected outcomes.
  • This participant notes that higher energy photons lead to more complex interactions, moving beyond the simple emission of electrons as described by Einstein's equation.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility and safety of using gamma radiation for energy capture. While some acknowledge the theoretical energy potential, others emphasize practical limitations and safety concerns, indicating that the discussion remains unresolved.

Contextual Notes

Participants highlight the complexity of interactions involving gamma radiation, suggesting that assumptions about the photoelectric effect may not apply in this context. There is also mention of the need for specific calculations to understand the practical implications of using gamma radiation for energy generation.

Thundagere
Messages
159
Reaction score
0
I read earlier that the photoelectric effect is when electromagnetic radiation essentially overcomes an electrons binding energy and converts it to electricity, which is how solar panels function.
But why is it that gamma radiation isn't being used to capture energy? If gamma radiation has a higher frequency, then it should have more energy, and thus the KE of the released electrons should be more. So why is this not currently being done? Am I missing something?
 
Physics news on Phys.org
What you are missing is that Gamma rays are both deadly and rare. Sunlight is much safer and available almost everywhere.
 
To add to what Antiphon said, try doing a calculation where the output of 1 Curie of Cobalt-60 is completely converted to electricity using a solar panel, and you'll see just how little wattage this produces from a dangerously high 1 Curie source.
 
Thundagere said:
I read earlier that the photoelectric effect is when electromagnetic radiation essentially overcomes an electrons binding energy and converts it to electricity, which is how solar panels function.
But why is it that gamma radiation isn't being used to capture energy? If gamma radiation has a higher frequency, then it should have more energy, and thus the KE of the released electrons should be more. So why is this not currently being done? Am I missing something?

There's a little bit of misunderstanding here.

The "photoelectric effect" that we normally deal with is the phenomenon of light impinging on a surface, and then the liberation of electrons from that surface. In fact, if we want to be even more precise, the phenomenon that is described via the Einstein photoelectric effect is the impinging of light of a certain frequency range on a metallic surface.

What this means is that it is the liberation of the conduction electrons that has overcome the work function of the metal. This is important to note because it is no longer a scenario that involves isolated atoms for one very obvious reason - isolated atoms do not have conduction/valence bands.

Now, the problem with gamma rays is that the interaction can be very different. Where there is a certain small probability of a "photoelectric effect" type phenomenon, gamma rays tend to interact more with not only a deeper, core-level energy states, but also with the nucleus of the material. When that occurs, you are no longer in the "photoelectric effect" regime (Einstein's equation no longer works). You can have a number of different phenomena going on - nuclear excitation, different types of scattering, etc.. etc. You just don't get a simple "electrons emitted at higher energy" phenomenon. Even x-rays can induce more complicated processes (that's why x-ray detectors are not some simple photodetectors that we use for UV/visible/IR range).

The higher the energy of the photon, the more exotic/complex processes that can occur when it interacts with matter.

Zz.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 8 ·
Replies
8
Views
769
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 16 ·
Replies
16
Views
3K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 29 ·
Replies
29
Views
2K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K