Technician at CERN
ProjectFrom June 2021 to July 2022, I worked as a technician for the ATLAS experiment at CERN in Geneva, Switzerland.
Hanging out in the detector!
CIS Calibration
My main role was as an expert for the Charge Injection System for the ATLAS Tile Calorimeter. The Tile Calorimeter is a subsystem of the ATLAS detector that functions to measure the energy of the particles created in LHC collisions. The Charge Injection System (CIS) is one of three levels of calibration that this complex system undergoes in order to ensure that this energy reconstruction is accurate. CIS calibration sends a pulse of a known charge to the readout electronics and measures the response, and occurs for all modules in the detector a few times per week. Even if the detector is not on, monitoring the status of each module's CIS constants over time can help determine the health of the detector and indicate if electronics need maintenance. My coworker and I performed database updates of the CIS calibration constants around once per month, and presented on any unusual behavior.
Maintenance Work
I also helped with upgrades to the ATLAS Tile Calorimeter during Long Shutdown 2 (LS2) of the LHC. Primarily, I was responsible for building, testing, and installing over 250 isolation valves onto the cooling system that runs throughout the detector. This is so that the cooling to each of the ~250 modules in the Tile Calorimeter can be shut off if a leak occurs -- before this, a leak in one module provoked insufficient cooling to the surrounding 8-12 modules. Physically mounting all of these was tricky, as in some areas space was extremely limited. Additionally, I assisted the regular maintenance team with replacing the occasional faulty electronics inside Tile Calorimeter modules.
Replacing electronics inside of a module
Some maintenance spots were hard to reach!
Sample of isolation valves I installed. They are the pairs of silver "boxes" mounted on top of the blue modules.
Attached are some summary presentations my coworker, Dawit Belayneh, and I made about our work to the UChicago ATLAS team.