Undergraduate Research at Jefferson Lab

Simulation of the Hall C High Momentum Spectrometer Drift Chambers

Student: Jonathan E. Stelzleni

School: Purdue University

Mentored By: Mark Jones

The drift chambers of the High Momentum Spectrometer (HMS), in Hall C of Jefferson Lab, are used to determine the trajectory of particles. The main focus of this project was to simulate the drift chambers, obtain their properties, and compare to the HMS drift chambers. Garfield++, a simulation toolkit derived from ROOT, was used to simulate the drift chamber. Using this toolkit, a cell of the drift chambers was successfully simulated with properties comparable to the drift chambers of the HMS. The electric fields surrounding the sense wires, in both the simulation and the HMS chambers, were found to be slightly different. Drift velocities were also compared, which showed similar values, but because the different electric fields and accidentals in the HMS data they were not exact. Garfield++ provides many additional functions, such as the simulation of electron avalanches and high energy electron tracks, which are explored. These simulations help to provide insight into how drift chambers function in practical use.