Particle Acceleration Radiation

[Fullhawking]

I know there is radiation associated with circular particle accelerators because of the change in velocity and things of this nature. Would there be any radiation associated with an electrostatic linear accelerator? I think the only source would be from when the beam hits the target but I am not positive.

 

[jonnylane]

I think it depends on the type of LINAC. In radiotherapy applications, there are shielding issues (obviously), but I'm not sure about the radiation emmission. I'll go and read some hardware manuals now...

 

[selfAdjoint]

I don't know anything definite, but it would seem to me that the electrons in a LINAC would be subject to fierce accelerations in order to bring them up to the target with the rated energy. And accelerated electrons _will_ radiate...

 

[jonnylane]

Originally posted by selfAdjoint
I don't know anything definite, but it would seem to me that the electrons in a LINAC would be subject to fierce accelerations in order to bring them up to the target with the rated energy. And accelerated electrons _will_ radiate...

but arn't the methods different? In the LINACS' we use here in the hospital, they use resonant microwave cavities in order to accelerate electrons. I'm not sure if this makes a difference. In any case, there is shielding in place to at least hold on to the microwaves, but is there an alterior motive to the shielding.

The question remains..

 

[Fullhawking]

Very interesting, I have done some additional looking on the internet but have not found anything really. I see the need for microwave shielding but electrostatic accelerators do not employ them.

 

[vanesch]

ALL accelerating charges radiate. When they are confined (by magnetic fields) to circular orbits, they emit what's called "synchrotron radiation", but also when they are linearly accerated they radiate. However, you can easily work out that the acceleration of a relativistic electron of a few GeV on a circular orbit of a few hundred meters across is MUCH BIGGER than the acceleration of the same electron in the cavities of a linac. So the resulting electromagnetic radiation intensity is also different. BTW, have a look at a modern synchrotron, such as www.esrf.fr to find out how this radiation (X-rays) are used...

cheers,
Patrick.