Can a single atom be excited by a single photon in a vacuum tube?

[lucas_]

I need electron transition detector that can respond to a dozen of photons.. so the atoms detector needs to be about just a dozen too.. I need something that can read it in an output.. what instruments is this? Geiger counter detects radiation by the click of the device.. I need something similar where the dozen atoms can click if it detect photons. I'll use it in a totally sealed dark room and an experiment. What device can I use? solar cells and bolometer won't do because they are based on electrons moving in the lattice and not from transition from excited to ground state.. what exact device or detectors (I can afford) that can detect transition from excited to ground state when it detect photons (need the sensitivity that is why I need one dozen or less atoms/photons)?

 

[Drakkith]

I don't think you've provided enough details for us to help you. What exactly are you doing? What's your specific setup?

 

[lucas_]

I don't think you've provided enough details for us to help you. What exactly are you doing? What's your specific setup?

I'd like to test an electron in a single hydrogen atom can get excited to high orbital and upon transition back to ground state would emit a photon. Just this simple. Can you detect a single atom or how many atoms are minimum for our instrument to make a detection (and what instrument is that)?

 

[Drakkith]

You won't be detecting the atom itself, but the photon it emits. Perhaps a photomultiplier?
http://en.wikipedia.org/wiki/Photomultiplier

 

[lucas_]

You won't be detecting the atom itself, but the photon it emits. Perhaps a photomultiplier?
http://en.wikipedia.org/wiki/Photomultiplier

This works by photoelectric effect and secondary emission. I was referring to photons coming from the electron transition in an atom. Any instrument where you can detect the returned photons from a single or small numbers of atoms? Is there any spectroscopy that detects photons from these electron transitions and how many minimum atoms required?

 

[Drakkith]

I'm not sure what you want. All photon detectors rely on converting the energy deposited by a photon into an electric current or voltage. There's simply no other way to amplify the signal.

 

[lucas_]

I'm not sure what you want. All photon detectors rely on converting the energy deposited by a photon into an electric current or voltage. There's simply no other way to amplify the signal.

In the photomultipier, the original photon hits an electron which goes to the photocathode, I'm looking for a photon that hits the electron in an atom which excites it to higher orbital and upon transition back to ground level emits a photon which goes to the photocathode.. is there no such thing? why?

 

[Drakkith]

That has nothing to do with the detector. The detector would function exactly the same in both cases. You'd need something to excite the atom in the first place. For that, I can't help you.

 

[lucas_]

That has nothing to do with the detector. The detector would function exactly the same in both cases. You'd need something to excite the atom in the first place. For that, I can't help you.

For others. What would happen if you have a single atom in a vacuum tube and a single photon is emitted to it in a totally dark room. would the single photon hit the single atom electron anywhere or won't it? I'm imaging a wave being sent from the emitter and the wave can hit the atom located anywhere... and upon hitting it, the wave becomes a photon and interacts with the electrons. Is this why a single photon would always hit the single atom located anywhere?