Undergraduate Research at Jefferson Lab

Recommissioning the Qweak Vertical Drift Chambers

Student: Mitchell Kerver

School: Christopher Newport University

Mentored By: Brad Sawatzy

Jefferson Lab's Hall C experimental hall has been in the process of constructing the new Super High Momentum Spectrometer, or SHMS. Part of the construction of the SHMS requires installation of several different types of detector packages, as well as their operating software. The SHMS will have two planes of Vertical Drift Chambers (VDC), two hodoscopes, a Cherenkov detector, and an array of calorimeters. VDC's similar to those being installed in the SHMS were used in Hall C for the Qweak experiment. This project focused on the refurbishment of these chambers to be recommissioned for use at another DOE facility. Preparing the chambers to be recommissioned required replacing the chamber's discriminator cared with refurbished "nanometric" cards. The chambers were filled with an Argon and CO₂ gas mixture and underwent "conditioning". A cosmic ray trigger was then set up to test the chambers. In addition to recommissioning the chambers, an event display program was developed to help reconstruct a 3D display of the SHMS detectors and particle tracks. The event display will now be able to take experimental data and provide a visual projection of each event from both the HMS and SHMS.