Off-resonant transition losses during Doppler cooling of magnetically trapped antihydrogen

Marta U. Sokolska

A supplement to my Bachelor's thesis from June 2026 at University of Groningen.

In experimental particle physics, antihydrogen is laser cooled to increase the precision of measurements. During the cooling process, a portion of the antiatoms is lost however. This thesis built upon previous work by the ALPHA collaboration at CERN, implementing a computational model to study a proposed loss pathway caused by off-resonant excitations by the cooling laser. In particular, the dependence of the loss rate strength on the trapping magnetic field was investigated. I found that this loss rate is lower in stronger magnetic fields, as well as that more losses happen at higher temperatures in the beginning of the cooling period. The predicted losses underestimate the experimentally observed losses, suggesting that while this pathway does contribute to the losses, it is not the full explanation.

Running instructions

The code is contained within one Pluto.jl notebook (notebook.jl), reproducible with frozen dependencies.

• To quickly view the notebook online without setting up an environment use this link.
• To run the notebook locally, follow the instructions at plutojl.org.