Anatomy of a Linac with Dr Brendan Whelan

ACRF Image X Institute Summer Lecture Series 2022 - Week 2
Linear accelerators are the workhorses of radiation oncology, used to deliver therapeutic photon and electron beams to treat cancer. In this lecture, we will delve into how a linear accelerator actually functions, with a particular focus on the beam forming components. You will learn: how we generate electrons, how we use resonant microwaves to accelerate them to nearly the speed of light, and how these are converted to photons.

[@AH-jt6wc]

Thank you very much for this presentation. What is most impressive is your physics montage where you succeeded to explain things without writing a single equation !

[@BM-jy6cb]

I'm surprised there were so few questions at the end of this. Who were the audience - was it a YT livestream? A fascinating topic, and we all owe our thanks to physicists like Brendan without whom cancer would still be death sentence.

[@DogWithHangover]

You can use a tungsten coated diamond target to boost power density significantly.

[@AH-jt6wc]

14:53 : I have 3 problems: 1) If we assume the distance that has to be traveled is Lambda then Lambda*f = the speed of light not more than C (which is still impossible for a particle other than photon) 2) It is a standing wave (Lambda/2 between 2 max, Lambda/4 between a max and a min) and if I wanna reach the node at the precise moment where the middle max is going to switch then I have to travel a distance of Lambda/4 (not lambda) in a T/4 seconds (not in T) which still gives C as a speed 3) To me, Extending the cavity will not solve the spark issue and the conductive losses. In other words the quality factor of the cavity will remain the same because it depends only on the reflection on the cavity edge. Usually the cavity volume influence the quality factor but that's because they are losses INSIDE the cavity because there is a dielectric for example which not the case here for the sake of the explanation simplicity en.wikipedia.org/wiki/File:Linear_accelerator_animation_16frames_1.6sec.gif

[@brendanwhelan5195]

Am I trending yet?

[@GishSteven]

To me you are!