Vacuum simulations with MolFlow+

CERN, 12-13 March 2023
Building 30, room 2-005

About the course

This course is an introduction to a 3D Monte Carlo simulator for ultra-high vacuum. It is intended for those with little or no previous Molflow experience.

• There will be one exercise where we learn the user interface, and working together, we calculate the effective pumping speed of a NEG cartridge
• In the second exercise, students will solve a more realistic accelerator vacuum problem, also dealing with some common modeling issues

You could help save time in the beginning if you prepared in advance by installing Molflow and downloading the exercise files. Thank you!

Preparation steps

1. Download Molflow 2.9.21 (choose your OS among the "binaries"). For the tutorial, the easiest is to run the Windows version. Mac or Linux builds available from the page, but it might be possible that you need to build the solution from source. Note that for each OS, you have instructions on how to install it, below the download links. Check if it runs on your desktop/laptop: if not, get in touch with us on the forum.
2. Download the source files (geometry) from the links below.
3. It is recommended to have a mouse, as it's difficult to work with a 3D editor with only a trackpad.

Downloadable content

1. Source files (geometry) required for exercises: juas2024_source_files.zip
   After downloading, extract it to a folder that you can access later (don't try to open the zip file in Molflow directly, as it countains 4 other files). Note that the zip file itself contains other two zip files: you don't need to extract those (they are opened directly by Molflow)
2. Handouts containing instructions: juas_training_2024.pdf
3. Intro presentation about Monte Carlo simulations: molflow_intro_juas_2024.pptx (it will be presented, you don't need to download)

Direct links for exercises

You don't need to download these, as they are contained in the zip file above.

First exercise: effective pumping speed of a NEG pump

Geometry (STL): neg_cartdridge_pump.stl

Accelerator midplane (to insert): pump_profile.zip

Second exercise: pressure profile of an accelerator part

Geometry (STL): extractor.stl

Mid-plane profile (to insert): accelerator_midplane.zip