Summer student project presentations 2020

The purpose of SiPM pulse processing is to evaluate the gain of the device with the help of dark pulses. The process starts by preparing the pulses to reduce the bias, then the charge is extracted through a window integration and finally a histogram with a fitting was made to analyze the gain. All of the steps above were done with a series of Python programs.

A preliminary investigation based on the rich literature to identify boosted top quarks, at the LHC’s Atlas
detector. The use of low-level jet information such as constituent transverse momentum and location as
input to the neural network. We find the network is most sensitive to constituent order when compared
to the preprocessing done in the literature.

DEAP-3600 is an underground dark matter detector located in Sudbury, ON. Cosmic muons are subatomic particles created in the upper atmosphere via cosmic ray interactions with air molecules. These particles can then penetrate more than 2 km (6000 m.w.e.) through solid rock to the position of the detector and be seen. An annual modulation is expected in the measurement of weekly average muon flux over the 3-year dataset. This would correlate to atmospheric temperature variations occurring seasonally, which impact muon production. Various studies have been done at other underground detectors to quantify the correlation between muon flux and atmospheric temperature, though all have been at significantly shallower depths. The results from this analysis will be the first measurement of this relationship below a depth of about 3500 m.w.e., and additionally this study is useful for understanding cosmogenic backgrounds in the ongoing dark matter search.

We are developing novel technology to assay 233U and 229Th by AMS in copper. The largest challenge is to produce standard targets for the calibration of the measurements. This involves making sintered copper targets with known 233U and 229Th concentrations for the creation of such standards. A detailed procedure and various investigation into the topic of interest is outlined.

Many theories propose adding a dark sector to the SM and copying how interactions are modeled based on normal QCD. Some of these theories lead to the creation of so-called ‘emerging jets’ where SM particles emerge into the ATLAS detector with displaced vertices. This would create a unique signal which can be searched for in ATLAS. A preliminary investigation into the possibilities of multivariate analysis methods through the use of Boosted Decision Trees (BDTs) was performed to evaluate the level of improvements to be gained over the current Run-2 emerging jets analysis.

During operation of EXO-200 a phenomenon referred to as glitches was observed, these glitches are essentially transient signals recorded on the high voltage supply line to the TPC. The HV R&D program at Carleton is investigating the possible connection between glitches and breakdowns in a mock-up of the EXO-200 TPC called miniEXO. In order to better inform experimental work a model in LTSpice has been created for the miniEXO TPC and has been used to simulate first order breakdown events.

As we move into run 3 of the new High Luminosity LHC (HL-LHC), many parts of the ATLAS detector have to go through a upgrades to keep up with the increased event rates. One of these upgrades is the New Small Wheel (NSW) which is part of ATLAS’ Muon Spectrometer. As a necessity, detailed simulations of the NSW must be run and tuned to test data to accurately reproduce singles expected in run 3. A study into the single point resolution of the small-strip thin gap chamber (sTGC), used as the main trigger of the NSW, is done to better tune current NSW simulations.