Can an amatur biult Cyclotron power a free electron laser?

AI Thread Summary
The discussion centers on the feasibility of using an amateur-built cyclotron to power a free electron laser (FEL). Key concerns include the ability to produce 1 nC of charge in approximately 10 ps pulse duration with a low emittance, which is essential for effective FEL operation. Participants emphasize the importance of using a photoinjector, which requires precise laser pulses and synchronization, rather than relying on Tesla coils for electron generation. The complexities of beam physics and the need for a solid understanding of the underlying principles are highlighted as critical for anyone attempting such a project. Overall, the conversation stresses the technical challenges involved in successfully creating an FEL.
mimic
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has anyone attempted this as a project?
 

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mimic said:
has anyone attempted this as a project?

Forget about the cyclotron itself. Can you just tell me how you are going to produce 1 nC of charge in roughly 10 ps pulse time scale with an emittance of 1 mm-mrad or better? That is the standard to produce a FEL using a typical undulator insertion device.

Zz.
 
ZapperZ said:
Forget about the cyclotron itself. Can you just tell me how you are going to produce 1 nC of charge in roughly 10 ps pulse time scale with an emittance of 1 mm-mrad or better? That is the standard to produce a FEL using a typical undulator insertion device.

Zz.

I planned to use a very high resolution modern computer based signal generator in conjuction with a very specialized amplifier. To drive a pair of large specialy tuned tesla coils to produce the 1 nC of charge at roughly 10 ps pulse time,The Beam spot radius is the hard part... I was hoping i might be able to focus it with electro magnets(focusing coils) before entering the undulator. does that sound viable??


ps:please excuse spelling
 
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mimic said:
I planned to use a very high resolution modern computer based signal generator in conjuction with a very specialized amplifier. which drives pair of large specialy tuned tesla coils to produce 1 nC of charge in roughly 10 ps pulse time,the Beam spot radius is the hard part... i was hoping i might be able to focus it with electro magnets

please excuse spelling

Er.. how? Tesla coils? What does that have anything to do with your ability to create 10 ps electron bunches? What do you think most FEL facilities use to do that? A Photoinjector! And the magnetic field has zero ability to affect the TRANSVERSE emittance of the electron beam, which is what will muck up ANY FEL.

Again, this is all way before the bunches get into your "cyclotron". So we haven't even talked about the problems that pop up in there.

Zz.
 
ZapperZ said:
the magnetic field has zero ability to affect the TRANSVERSE emittance of the electron beamZz.

so how does the undulator work?

the t-coils are to power the Photoinjector.
 
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mimic said:
so how does the undulator work?

Yikes. Don't you think you need to know this before you start wanting to produce an FEL?

the t-coils power the Photoinjector

Er... power? Do you know what a "photoinjector" is?

Zz.
 
ZapperZ said:
Yikes. Don't you think you need to know this before you start wanting to produce an FEL?



Er... power? Do you know what a "photoinjector" is?

Zz.

RF photoinjector is a kind of high-brightness electron beam source.

to work it requires high potencials at rf frequency which you generate from specalised tesla coils(tuned resonant coils).
 
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mimic said:
RF photoinjector is one kind of high-brightness electron beam sources.

it requires high potencials at rf frequency which you generate with specalised tesla coils

What's with this obsession with tesla coils?

A photoinjector is an electron source, sure, but you missed a very important element of it - the PHOTO part. It generates electron pulses via intense laser pulses. These laser pulses are 10 ps long, something NOT very easy to do. We have something the size of a refrigerator called a ReGen (regenerative amplifier) that does the pulse timing and pulse shaping. You then have to mode-lock the trigger with the RF that goes into the photoinjector cavity, which, btw, has to be extremely carefully TUNED to the fundamental TEM mode frequency coming from the Klystron. Then you need to be able to get the laser pulse to hit the photocathode at just the RIGHT timing on the RF phase to cause not only an acceleration but also a bunch compression. Not only that, the photocathode you choose must have a work function that is JUST below the photon energy from the laser because you want the electrons to be generated COLD to minimize a large energy spread of the photoelectrons... etc... etc.

Again, this is JUST at the photoinjector side of it. We haven't even gotten into the ring yet.

I work at a facility that not only does research on producing high brightness beams for particle colliders, but also for FEL, and in particular SASE FEL with a potential to produce THz radiation. I think before you embark on something like this, you should at least understand the physics involved (not just the engineering aspect), especially beam physics, and also go visit an FEL facility. Reading about it, and seeing pictures, are very superficial.

Zz.
 
ZapperZ said:
What's with this obsession with tesla coils?.
its those big sparks :rolleyes:

ZapperZ said:
A photoinjector is an electron source, sure, but you missed a very important element of it - the PHOTO part. It generates electron pulses via intense laser pulses. These laser pulses are 10 ps long, something NOT very easy to do. We have something the size of a refrigerator called a ReGen (regenerative amplifier) that does the pulse timing and pulse shaping. You then have to mode-lock the trigger with the RF that goes into the photoinjector cavity,
.

what type of laser is it?


ZapperZ said:
Again, this is JUST at the photoinjector side of it. We haven't even gotten into the ring yet.
:eek:

ZapperZ said:
I think before you embark on something like this, you should at least understand the physics involved (not just the engineering aspect), .

Zz.

well.. give me half a chance, that's why I am here :wink:
 
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  • #10
ok so the photoinjector is pumped with a laser pulse... your obviously the person to ask,so perhaps you could anser a few more questions.

What can you tell me about the laser itself?,is it solid state, tube,die, diode?

What wavelength (NM) output is it?

How many whatts of output does it produce?

How do you time the laser pulse's?,is it with the lasers input or is it done by a unit somewhere after the beam leaves the laserhead?
 
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