TEMPERATURE SIMULATION AND CALCULATION FOR THE ANTIMATTER EXPERIMENT: GRAVITY, INTERFEROMETRY, AND SPECTROSCOPY

Open Access
Author:
Brown, Stephanie Meghan
Area of Honors:
Astronomy and Astrophysics
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Miguel Alejandro Mostafa, Thesis Supervisor
  • Christopher Palma, Honors Advisor
Keywords:
  • antimatter
  • gravity
  • antihydrogen
  • cern
Abstract:
An important aspect of an antimatter plasma is the temperature, and it is critical to the success of the AEgIS experiment that we are able to accurately determine the temperature of our plasma and hence the effectiveness of our cooling systems. The goal of the AEgIS experiment is to measure the acceleration due to gravity on antihydrogen atoms. The atoms will be allowed to free fall. The slower the particles tangential velocity, the larger the vertical deflection will be. Since our detectors have a finite spacial resolution, we must require that the temperature of the particles is below a threshold (~ micro K). This thesis discusses a simulation that mimics the measurement. The temperature is calculated using the Maxwell-Boltzmann equation to relate kinetic energy to temperature. A potential well contains the particles. The potential well is slowly lowered so that small numbers of particles escape at a time. Since we know particle number as a function of energy, we can determine the temperature of the ensemble. We treat the particles classically and neglect quantum effects. We only extract the first 1% of the particles in the simulation as, in the actual experiment, we want to remove only the high energy tail of the particles. Doing this will minimize the effects of space charge and evaporative cooling. We use this simulation to examine the effects of different parameters such as temperature, particle number, and ramping speed on the measurement. In addition, we will examine the fit used to retrieve the temperature and the error inherent in the calculation, which contains some approximations.