Menu

Discussion Forum

New Discussion
Filter

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Heat load on crystal (induced by X-ray beam)

Posted May 23, 2024, 4:36 a.m. EDT Fluid & Heat, Heat Transfer, Modeling Workflow 1 Reply

Julia
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hey,

I'm still quite new to COMSOL and am trying to simulate the heat load on a crystal induced by an X-ray beam (I want to see the time-dependent development). We use the crystal to diffract the beam (Bragg diffraction), so the X-rays get partly transmitted, diffracted and absorbed. I'm struggling with finding approaches for this specific problem and would be very grateful for every help!

From what I understand there are many different modules available when it comes to heat simulations. Furthermore, the heat transfer meachnism are conduction, convection and radiation and I guess the latter is what applies in my case.

My first idea was to use the deposited beam power to simulate the temperature in the volume, but I'm not sure if this is the right approach and if it might have to be combined with something else, such as heat flux?

My other idea was to use the "Radiation in participating media", but I'm also not sure if the can be used as a stand-alone feature and if the beam profile can be defined somehow.

Thanks in advance!

1 Reply Last Post May 23, 2024, 11:51 a.m. EDT
Dave Greve
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 6 months ago May 23, 2024, 11:51 a.m. EDT

Interesting problem (although I suspect this has been thought about by the people who make double-crystal diffractometers and Bragg lenses).

Transmission clearly induces no heat load (although it would heat up any supporting structure). Diffraction results in a momentum transfer which would ultimately become phonons, so that heat can be calculated. Probably the heat load is close to uniform as X-ray penetration tends to be large.

Unless things are getting really hot radiation is probably not significant. I would neglect radiation until last, calculate with conduction only and then try to add convection.

Interesting problem (although I suspect this has been thought about by the people who make double-crystal diffractometers and Bragg lenses). Transmission clearly induces no heat load (although it would heat up any supporting structure). Diffraction results in a momentum transfer which would ultimately become phonons, so that heat can be calculated. Probably the heat load is close to uniform as X-ray penetration tends to be large. Unless things are getting really hot radiation is probably not significant. I would neglect radiation until last, calculate with conduction only and then try to add convection.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content