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.

Particle tracing in magnetic field

Please login with a confirmed email address before reporting spam

Hi,

I have a radially symmetric magnetic lens. I want to simulate how input particles (with xy distribution and certain velocity) go through the magnetic lens and what is the distribution. I used Magnetic Fields and Charged Particle Tracing studies. Since the magnetic lens is radially symmetric, I can use 2D simulation to calculate the magnetic field. However, Charged Particle Tracing is only available in 3D. So I have to do the whole simulation in 3D. In addition to the increased simulation time, I observed simulation errors when the electron beam focus is less than 5um. I uses a 2D circular beam with initial positions on Projected plane grid. I expect the beam to be still circular and still on grid with rotated coordinates. Instead, I got very irregular shaped spot with electron distributions that look random. I significantly increased mesh sampling and uses fine time steps near the focus, but still couldn’t resolve the problem. I’m wondering if there are any good suggestions to this problem.

I finally tried to use field precision to solve this problem. It’s much faster since it uses 2D magnetic field and it still takes 2D input electron distributions. It also gives more accurate results. I wish COMSOL could have similar feature.

Does anyone have similar problems?

Thanks! Jingyi


0 Replies Last Post 08.03.2019, 12:57 GMT-5
COMSOL Moderator

Hello Jingyi Xiong

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

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.