Accelerator and Beams - Tools for Discovery and Innovation

Click For Summary

Discussion Overview

The discussion revolves around the principles and applications of particle accelerators, with a focus on synchrotron radiation and its implications for kinetic energy. Participants explore various aspects of particle acceleration, including misconceptions about particle colliders and the physics underlying synchrotron radiation.

Discussion Character

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

Main Points Raised

  • Some participants emphasize that particle accelerators are often misunderstood as solely related to high energy physics, highlighting that many applications exist outside this realm.
  • A participant shares a resource on the principles of charged particle acceleration and raises a question about the relationship between magnetic forces and kinetic energy, referencing a statement from the book by Humphries.
  • Another participant discusses synchrotron radiation, suggesting it results from the Lorentz force and questioning how it relates to the energy of the particle.
  • There is a query regarding the source of energy for synchrotron radiation, with participants discussing whether it involves a change in mass or is equivalent to the magnetic energy applied to the particle.
  • One participant warns against applying the equation E=mc^2 in this context, asserting that the phenomenon is explained through classical electromagnetism, while another introduces a different energy-momentum relation.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between synchrotron radiation and kinetic energy, as well as the implications of magnetic forces on particle energy. The discussion remains unresolved with multiple competing perspectives on these topics.

Contextual Notes

Participants reference specific statements from literature that may require further clarification or context. There are unresolved questions about the energy dynamics involved in synchrotron radiation and the applicability of certain equations in this context.

ZapperZ
Staff Emeritus
Science Advisor
Homework Helper
Insights Author
Messages
32,819
Reaction score
4,723
The Division of Physics of Beams of the American Physical Society (APS) has produced this wonderful brochure titled "http://www.aps.org/units/dpb/upload/brochure.pdf" ". It essentially describe what a particle accelerator is, and more importantly, what it is used for.

The main purpose here is to eliminate the wrong myth that "particle accelerator" automatically means "particle collider" in high energy physics. Nothing could be further than the truth, and hopefully, someone reading this brochure will get the idea that the MAJORITY of the application for a particle accelerator has NOTHING to do with high energy physics.

A supplement for this brochure is a useful article written a while back by Michael Turner titled "http://scitation.aip.org/journals/doc/PHTOAD-ft/vol_56/iss_9/10_1.shtml" ", that essentially tried to convey the same message.

Zz.
 
Last edited by a moderator:
Physics news on Phys.org
Here is a free downloadable book on the "Principles of Charged Particle Acceleration" by Stanley Humphries. warning: large file -11.3 MB
http://www.fieldp.com/cpa.html
Or you can get a used one from Amazon.com for $75.00
 
Last edited:
Bob S said:
Here is a free downloadable book on the "Principles of Charged Particle Acceleration" by Stanley Humphries. warning: large file -11.3 MB
http://www.fieldp.com/cpa.html
Or you can get a used one from Amazon.com for $75.00

Thanks for the link, it looks like good read. i just started reading the introduction and on page 3 Humphries states that " magnetic forces cannot affect a particles kinetic energy".
1 question.
Do the photons of synchrotron radiation not carry away/convert the kinetic energy of the particle?
 
scupydog said:
Thanks for the link, it looks like good read. i just started reading the introduction and on page 3 Humphries states that " magnetic forces cannot affect a particles kinetic energy".
1 question.
Do the photons of synchrotron radiation not carry away/convert the kinetic energy of the particle?
You are correct in that sunchrotron radiation is a direct consequence of the F = q(v x B) (Lorentz) force. I think the author was trying to say is that since both B and F are orthogonal to v, no work is being done, and the force does not add to or subtract from the velocity.
Bob S
 
thx for reply Bob, where does the energy come from for synchrotron radiation... is there a change in mass of the charged particle, or is the amount of energy needed for S.R. equal to the magnetic energy/force applied to the particle.
 
scupydog said:
thx for reply Bob, where does the energy come from for synchrotron radiation... is there a change in mass of the charged particle, or is the amount of energy needed for S.R. equal to the magnetic energy/force applied to the particle.
The synchrotron radiation comes from the deflection of positrons or electrons in bending magnets. it orthogonal to the velocity in the center of mass coord system, but is very forward radiation in the lab system, and comes from the particles' kinetic energy, which is replaced by RF cavities. I have seen potted copper coils on magnets turn black and crack by synchrotron radiation damage.
 
Last edited:
Hi Bob i,m interested in acceleraters and have visited CERN do you work with acceleraters?
 
scupydog said:
thx for reply Bob, where does the energy come from for synchrotron radiation... is there a change in mass of the charged particle, or is the amount of energy needed for S.R. equal to the magnetic energy/force applied to the particle.

Er... you should be very careful here not to use "E=mc^2" in this process. This is simply classical E&M. The electron (or electron bunch) is losing kinetic energy in such a process.

Zz.
 
ZapperZ said:
Er... you should be very careful here not to use "E=mc^2" in this process. This is simply classical E&M. The electron (or electron bunch) is losing kinetic energy in such a process.Zz.

How about E2= (pc)2+ (m0c2)2 ?