Improving the Sensitivity and Data Analysis Techniques of the ARIANNA Detector with Deep Learning

• Main Author: Anker, Astrid Lund
• Other Authors: Barwick, Steven
• Format: Thesis
• Language: English
• Published: eScholarship, University of California 2023
• Subjects: Physics; Particle physics; Artificial intelligence; ARIANNA; Deep-Learning; Neutrinos; Antarc*; Antarctic
• Online Access: https://escholarship.org/uc/item/5bq04830; https://escholarship.org/content/qt5bq04830/qt5bq04830.pdf

The ARIANNA experiment is an Askaryan detector designed to record radio signals induced by neutrino interactions in the Antarctic ice. Because of the low neutrino flux at high energies, the ability to increase detector sensitivity and data analysis techniques is crucial to maximizing the number of neutrinos measured. In this work, deep learning techniques are explored to improve real-time data collection capabilities and offline neutrino searches. As an introduction, the broader field of multi-messenger astronomy is outlined, an overview of the ARIANNA experiment is provided, and deep learning techniques are detailed. Next, two projects utilizing deep learning to analyze ARIANNA data are presented. In the first project, the amplitudes of the trigger threshold are limited by the rate of triggering on unavoidable thermal noise fluctuations. Here, a real-time thermal noise rejection algorithm is created that enables the trigger thresholds to be lowered, increasing the sensitivity to neutrinos by up to a factor of two (depending on energy) compared to the current ARIANNA capabilities. A deep learning discriminator, based on a Convolutional Neural Network (CNN), is implemented to identify and remove thermal events in real time. This project demonstrated a CNN trained on Monte Carlo data can run on the current ARIANNA microcomputer; the CNN retained 95% of the neutrino signal at a thermal noise rejection factor of 100,000, compared to a template matching procedure which reached only 100 for the same signal efficiency. The results are verified by feeding in generated neutrino-like signal pulses and thermal noise directly into the ARIANNA data acquisition system. There are further studies of the CNN including deep learning network interpretability and hyperparameter optimization. Lastly, the CNN is used to classify cosmic rays events to confirm they are not rejected; the network properly classified 102 out of 104 cosmic ray events as signal. In the second project, deep learning is used in an offline analysis to classify ...