Can an amatur biult Cyclotron power a free electron laser?

Click For Summary

Discussion Overview

The discussion revolves around the feasibility of using an amateur-built cyclotron to power a free electron laser (FEL). Participants explore the technical requirements for generating the necessary electron pulses and the role of various components, such as photoinjectors and Tesla coils, in this process.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants inquire whether anyone has attempted building a cyclotron for this purpose.
  • One participant emphasizes the challenge of producing 1 nC of charge in approximately 10 ps pulse time with an emittance of 1 mm-mrad or better, which is critical for an FEL.
  • Another participant proposes using a high-resolution computer-based signal generator and specialized amplifiers to drive Tesla coils for charge production, questioning the viability of focusing the beam with electromagnets.
  • Concerns are raised about the appropriateness of Tesla coils for generating short electron bunches, with a suggestion that photoinjectors are typically used in FEL facilities.
  • Discussion includes the importance of understanding the photoinjector's operation, particularly the need for laser pulses to generate electrons and the complexities involved in timing and tuning the system.
  • Participants discuss the specifics of laser types, wavelengths, and output power necessary for effective operation of the photoinjector.

Areas of Agreement / Disagreement

There is no consensus on the feasibility of using Tesla coils in this context, and participants express differing views on the necessary components and understanding required for successfully building an FEL.

Contextual Notes

Participants highlight the need for a solid grasp of both the physics and engineering aspects of FELs, indicating that there are significant technical challenges and prerequisites that must be addressed before pursuing such a project.

Who May Find This Useful

This discussion may be of interest to amateur physicists, engineers, and hobbyists exploring advanced particle acceleration and laser technology.

mimic
Messages
31
Reaction score
0
has anyone attempted this as a project?
 

Attachments

  • A4cyctrn.jpg
    A4cyctrn.jpg
    34.3 KB · Views: 490
  • felschema.gif
    felschema.gif
    4 KB · Views: 576
Physics news on Phys.org
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
 
Last edited:
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.
 
Last edited:
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).
 
Last edited:
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:
 
Last edited:
  • #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?
 
Last edited:

Similar threads

  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 26 ·
Replies
26
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 18 ·
Replies
18
Views
15K
  • · Replies 0 ·
Replies
0
Views
2K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 3 ·
Replies
3
Views
21K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 17 ·
Replies
17
Views
8K