Harnessing energy of internal electrons

[Moreno]

There is a known physical effect when an excited electron releases a photon of a higher energy than one been absorbed. It happens to both internal and external (valence) electrons. This effect is exploited in Doppler cooling. This is typically external electrons which are engaged in Doppler cooling. What about internal electrons? They seem to be capable to absorb ultraviolet and release X-rays of higher energies.

X-rays contain a lot of energy

Could this effect be exploited practically either for refrigeration/heat pumps or even some useful work generation? For example, we may try to use X-rays to heat some material and use it to bring some heat engine to action...

Edited March 18, 2018 by Moreno

[swansont]

Doppler cooling is typically using a closed transition — same lower and upper states. The only energy difference in such a transition is the minuscule Doppler shift, because absorption of a photon causes the atom to recoil and thus have a different velocity at emission vs absorption. The shift is typically less than the natural linewidth of the transition, so you would be hard-pressed to see it. But that's not the reason the atom gets cooled.

X-rays are not used because of the dearth of coherent light sources and optics. Even UV is hard to do. Laser interactions with ground state Hydrogen involve deep UV, which people would like to do.

[John Cuthber]

14 hours ago, Moreno said:

X-rays contain a lot of energy

Where do you plan to get them from?

Trying to use deep lying electrons to create useful energy is like trying to use an underground pool to create hydro-electric power.

There's no "down" for the water to go

[Moreno]

1 hour ago, John Cuthber said:

Where do you plan to get them from?

Trying to use deep lying electrons to create useful energy is like trying to use an underground pool to create hydro-electric power.

There's no "down" for the water to go

I've read there exist such a physical phenomena (and I think it is quite a plausible info) that an internal electrons are capable to absorb ultraviolet photon, get excited and re-radiate X-rays. X-rays definitely are of higher energy than UV, so it doesn't look like a miniscule gain in energy.

I thought that external and internal electrons don't exist in thermodynamic equilibrium. They have different energy levels and subsequently absorb and radiate photons of different energies. This is typically external electrons which take part in chemical reactions and release energy when we burn fuel or use some hot substance to bring a heat engine into action. There exist some notable exceptions, such as d-orbital electrons in transition metals. But what if we use some physical effect to bring external and internal electrons into a sort of thermodynamic equilibrium? For example, we may make internal electron absorb UV photon, reradiate X-ray photon of much higher energy and then convert this X-ray photon with high efficiency using some method into many infrared or visible photons which could be readily absorbed by external electrons. When external electrons absorb them it will lead to temperature rise of the substance, and this is what we can use, basically, as an energy source to power a heat engine...

I'm not sure exactly what is the name of this effect, but it maybe related to this:

Quote

 

Inverse Compton scattering is important in astrophysics. In X-ray astronomy, the accretion disc surrounding a black hole is presumed to produce a thermal spectrum. The lower energy photons produced from this spectrum are scattered to higher energies by relativistic electrons in the surrounding corona. This is surmised to cause the power law component in the X-ray spectra (0.2-10 keV) of accreting black holes.^{[clarification needed]}

The effect is also observed when photons from the cosmic microwave background (CMB) move through the hot gas surrounding a galaxy cluster. The CMB photons are scattered to higher energies by the electrons in this gas, resulting in the Sunyaev-Zel'dovich effect. Observations of the Sunyaev-Zel'dovich effect provide a nearly redshift-independent means of detecting galaxy clusters.

Some synchrotron radiation facilities scatter laser light off the stored electron beam. This Compton backscattering produces high energy photons in the MeV to GeV range^[8] subsequently used for nuclear physics experiments.

 

https://en.wikipedia.org/wiki/Compton_scattering#Inverse_Compton_scattering

Edited March 19, 2018 by Moreno

[swansont]

29 minutes ago, Moreno said:

I've read there exist such a physical phenomena (and I think it is quite a plausible info) that an internal electrons are capable to absorb ultraviolet photon, get excited and re-radiate X-rays. X-rays definitely are of higher energy than UV, so it doesn't look like a miniscule gain in energy.

Not without some other source of energy, and you haven't provided a link. Something is missing.

29 minutes ago, Moreno said:

I thought that external and internal electrons don't exist in thermodynamic equilibrium. They have different energy levels and subsequently absorb and radiate photons of different energies. This is typically external electrons which take part in chemical reactions and release energy when we burn fuel or use some hot substance to bring a heat engine into action.

Those are chemical bonds.

29 minutes ago, Moreno said:

There exist some notable exceptions, such as d-orbital electrons in transition metals. But what if we use some physical effect to bring external and internal electrons into a sort of thermodynamic equilibrium?

That doesn't make much sense. Thermodynamic equilibrium means there is a temperature. Electron excitation is related to this in a gas (because you tend to have collisions which can excite the atom) but using E = kT even 10 eV requires 10^6 K.

If you have atoms at a million Kelvin colliding, they will just ionize the outer electrons.

You get these inner electrons excited by either electron collision (x-ray machines work this way) or photons of that energy.

 

29 minutes ago, Moreno said:

For example, we may make internal electron absorb UV photon, reradiate X-ray photon of much higher energy and then convert this X-ray photon with high efficiency using some method into many infrared or visible photons which could be readily absorbed by external electrons.

The devil's in the details. Which you can't just hand-wave away. (Step 2: then a miracle occurs)

29 minutes ago, Moreno said:

When external electrons absorb them it will lead to temperature rise of the substance, and this is what we can use, basically, as an energy source to power a heat engine...

It's not a source if you have this external energy input.

[John Cuthber]

1 hour ago, Moreno said:

I've read there exist such a physical phenomena (and I think it is quite a plausible info) that an internal electrons are capable to absorb ultraviolet photon, get excited and re-radiate X-rays. X-rays definitely are of higher energy than UV, so it doesn't look like a miniscule gain in energy.

I thought that external and internal electrons don't exist in thermodynamic equilibrium. They have different energy levels and subsequently absorb and radiate photons of different energies. This is typically external electrons which take part in chemical reactions and release energy when we burn fuel or use some hot substance to bring a heat engine into action. There exist some notable exceptions, such as d-orbital electrons in transition metals. But what if we use some physical effect to bring external and internal electrons into a sort of thermodynamic equilibrium? For example, we may make internal electron absorb UV photon, reradiate X-ray photon of much higher energy and then convert this X-ray photon with high efficiency using some method into many infrared or visible photons which could be readily absorbed by external electrons. When external electrons absorb them it will lead to temperature rise of the substance, and this is what we can use, basically, as an energy source to power a heat engine...

I'm not sure exactly what is the name of this effect, but it maybe related to this:

https://en.wikipedia.org/wiki/Compton_scattering#Inverse_Compton_scattering

And again...

Where do you plan to get the X rays from?

 

[Moreno]

1 hour ago, swansont said:

It's not a source if you have this external energy input.

In a regular heat pump we also have an external energy input, but still it is worth of.

[swansont]

5 minutes ago, Moreno said:

In a regular heat pump we also have an external energy input, but still it is worth of.

But there you are tapping into a reservoir of energy, which is absent here.

[John Cuthber]

1 hour ago, Moreno said:

In a regular heat pump we also have an external energy input, but still it is worth of.

And again...

Where do you plan to get the X rays from?

[Moreno]

1 hour ago, John Cuthber said:

And again...

Where do you plan to get the X rays from?

For example with help of lasers and bacteria:

(don'take it too seriously).

https://www.osapublishing.org/DirectPDFAccess/7CB74383-A152-6597-E90A223729A1DBA1_321582/oe-23-14-17909.pdf?da=1&id=321582&seq=0&mobile=not 

 

[John Cuthber]

Do you have any idea how inefficient lasers are, especially xray lasers?

[Sensei]

On 18.03.2018 at 11:30 PM, Moreno said:

What about internal electrons? They seem to be capable to absorb ultraviolet and release X-rays of higher energies.

If one of internal electrons (bound to atom) is absorbing energy from external source, like in your case, from x-ray or UV photon, it's jumping to higher energy level, and "at the same time" one of other internal electrons (which is normally at higher energy level than the first one), will emit photon, and will replace electron which just absorbed x-ray/uv photon.

Human analogy: you have queue of people, and one of them in the start or middle of queue is moving to the end of queue, the all other people in queue moves, as there is new place for them.