My inSPIRE profile Brian.A.Clark.1 and ORCID 0000-0003-4089-2245

Graduate: Ultra-High Energy Neutrinos

A schematic of an ARA station.

A schematic of an ARA station.

Broadly, I work on hardware, simulation, and analysis for the Askaryan Radio Array (ARA). ARA is a teraton in-situ ultra-high energy neutrino detector that is buried 200 meters deep into the radio-clear ice near the South Pole in Antarctica. The detector seeks to see the most energetic particles in the universe, neutrinos carrying energy between 10e17 and 10e20 electron volts–a masslesss particle with the effective energy of a thrown baseball!

In hardware, I work with Patrick Allison to lead the mechanical and electrical integration of the ARA Station Data Acquisition (DAQ) electronics, which were deployed in the 2017-2018 pole season. I journeyed to the South Pole in January 2018 for four weeks to lead the commissioning and calibration of these new detectors. See some photos here! I am particularly involved in the debugging, building, and characterization of the signal conditioning modules, but am also heavily involved in the power distribution system. The firmware that controls much of our electronics can be found at our GitHub.

In simulation, I work extensively with Dr. Carl Pfendner and Kaeli Hughes on the development of the AraSimQC software package which is the quality and control software for AraSim. AraSim is the Monte-Carlo package that simulates the interaction of the neutrino’s at pole, including their primary and secondary interactions, depth dependent attenuation and indices of refraction in ice, and final modeling of the radio signal’s arrival at a detector. AraSimQC focuses on simplifying the comparison of standard simulation output, allowing the collaboration to examine how revisions to simulation code affect the physics outcomes.

In analysis, I am mainly involved in ongoing work to understand our detector’s response to “target of opportunity” physics, such as solar flares. This largely involved designing new time and frequency domain analysis techniques, as well as assessing the system’s pointing capability.

I started work with Prof. Connolly in the fall of 2014. In the Spring 2016 I was awarded a National Science Foundation Graduate Research Fellowship to continue working with the ARA collaboration to develop hardware, simulation, and analysis techniques to discover ultra-high energy neutrinos.


Undergraduate: X-Ray Polarimetry and Stokes Parameters

I spent the majority of my undergraduate research working with Dr. Henric Krawczynski and the X-Calibur collaboration at Washington University in St. Louis on the development and testing of the x-ray polarimeter X-Calibur.

My project and honors thesis focused on analysis; I simulated and modeled the received polarization signals and their a posteriori distributions via Bayesian analysis. With Dr. Fabian Kislat, I conducted a first principles Monte Carlo simulation of the reception, analysis, and reconstruction of a polarization signal to better understand how to place confidence intervals on received signals. As the analysis of these signals demands extracting estimates from a measured distribution given a priori knowledge, our methods employed Bayesian inversion to set confidence intervals.

Our technique was the first to apply Stoke parameters to polarization reconstruction in the x-ray band (though they aS3D.mu5.tr5000.it10000re widely used in radio astronomy). To read more about our work with Stokes Paramters please see my honors thesis, or the paper in the Journal of Astroparticle physics.