Applications of X-ray Instrumentation for Dark Matter Searches with Cosmic-ray Antiparticles
Approximately 85% of the mass in the Universe is composed of dark matter. Scientific consensus is that this dark matter is comprised of some unidentified fundamental particle, but despite compelling evidence of abundant dark matter and precise observation of its gravitational effects, the nature of...
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| Format: | Thesis |
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Massachusetts Institute of Technology
2023
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| Online Access: | https://hdl.handle.net/1721.1/150702 |
| _version_ | 1811095392614350848 |
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| author | Rogers, Field Rose |
| author2 | Perez, Kerstin |
| author_facet | Perez, Kerstin Rogers, Field Rose |
| author_sort | Rogers, Field Rose |
| collection | MIT |
| description | Approximately 85% of the mass in the Universe is composed of dark matter. Scientific consensus is that this dark matter is comprised of some unidentified fundamental particle, but despite compelling evidence of abundant dark matter and precise observation of its gravitational effects, the nature of this material remains a mystery. The effort to reveal the fundamental properties of the dark matter is a central and and unifying theme of modern particle and astrophysics. Indirect dark matter detection centers on cosmic-ray signatures of possible dark matter annihilation or decay to Standard Model particles in the Galaxy. Relative to terrestrial experiments, such indirect dark matter searches benefit from the large size of the Galaxy and can probe broad classes of dark matter models including those that, due to low cross sections, evade both production at colliders and direct detection. The challenge for indirect dark matter detection lies in disentangling possible dark matter signatures from the large and often uncertain cosmic-ray fluxes arising from other astrophysical sources. At the same time, cosmic-ray particles, which are themselves agents of Galactic evolution, provide unparalleled probes of the Galactic environment and dynamics. This dissertation describes two complementary approaches to the interconnected worlds of indirect dark matter detection and cosmic-ray physics: first, searching for rare cosmic-ray species local to Earth, and second, using astrophysical techniques to observe the effects of cosmic-ray particles in remote regions of the Galaxy.
The General Antiparticle Spectrometer (GAPS) is an upcoming balloon mission to search for signatures of dark matter annihilation or decay in low-energy (<0.25 GeV/𝑛) cosmic-ray antinucleus fluxes. The goal of GAPS is to deliver 1) a precision cosmic antiproton spectrum in an unexplored low-energy region; 2) a first detection of cosmic antideuterons, a signature of new physics essentially free of astrophysical background; and 3) leading sensitivity to cosmic antihelium-3. To identify rare antinuclei out of the trillions of particles expected in flight, GAPS pioneers a novel exotic atom-based particle identification technique, which relies on >10 m2 of lithium-drifted silicon (Si(Li)) detectors to capture an incoming antinucleus into an exotic atom and measure the resulting X-ray and nuclear annihilation products. This dissertation details the development, noise performance, and tracking capabilities of the large-area, high-temperature Si(Li) detectors developed for the GAPS mission. Their performance is precisely characterized using a semiconductor noise model and has been shown to be stable over time. In addition, the GAPS sensitivity to cosmic-ray antiprotons is demonstrated in this work using a full instrument simulation, event reconstruction, and models of solar and atmospheric effects. With its large geometric acceptance, GAPS will detect ∼500 cosmic antiprotons per flight, producing a precision spectrum extending to lower energies than any previous measurement. This measurement will be sensitive to models of dark matter, evaporating primordial black holes, and cosmic ray propagation. It will also validate the exotic atom particle identification technique prior to the other GAPS analyses.
Beyond local detection in high-altitude particle detectors, cosmic ray populations can be probed remotely via the electromagnetic radiation they produce as they prop-agate through the Galaxy. Recent evidence points to enhanced particle populations of uncertain origin in the Galactic Center region. These unexplained particles challenge the conventional models of cosmic ray propagation used to predict the local fluxes critical for dark matter detection. Using X-ray observations of the giant molecular cloud Sagittarius B2, new upper limits are set on low-energy cosmic ray populations near the Galactic center. The limits are comparable to predictions from hydrogen ionization measurements, supporting the observation of elevated Galactic Center cosmic ray populations. |
| first_indexed | 2024-09-23T16:16:02Z |
| format | Thesis |
| id | mit-1721.1/150702 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T16:16:02Z |
| publishDate | 2023 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/1507022023-05-16T03:03:23Z Applications of X-ray Instrumentation for Dark Matter Searches with Cosmic-ray Antiparticles Rogers, Field Rose Perez, Kerstin Massachusetts Institute of Technology. Department of Physics Approximately 85% of the mass in the Universe is composed of dark matter. Scientific consensus is that this dark matter is comprised of some unidentified fundamental particle, but despite compelling evidence of abundant dark matter and precise observation of its gravitational effects, the nature of this material remains a mystery. The effort to reveal the fundamental properties of the dark matter is a central and and unifying theme of modern particle and astrophysics. Indirect dark matter detection centers on cosmic-ray signatures of possible dark matter annihilation or decay to Standard Model particles in the Galaxy. Relative to terrestrial experiments, such indirect dark matter searches benefit from the large size of the Galaxy and can probe broad classes of dark matter models including those that, due to low cross sections, evade both production at colliders and direct detection. The challenge for indirect dark matter detection lies in disentangling possible dark matter signatures from the large and often uncertain cosmic-ray fluxes arising from other astrophysical sources. At the same time, cosmic-ray particles, which are themselves agents of Galactic evolution, provide unparalleled probes of the Galactic environment and dynamics. This dissertation describes two complementary approaches to the interconnected worlds of indirect dark matter detection and cosmic-ray physics: first, searching for rare cosmic-ray species local to Earth, and second, using astrophysical techniques to observe the effects of cosmic-ray particles in remote regions of the Galaxy. The General Antiparticle Spectrometer (GAPS) is an upcoming balloon mission to search for signatures of dark matter annihilation or decay in low-energy (<0.25 GeV/𝑛) cosmic-ray antinucleus fluxes. The goal of GAPS is to deliver 1) a precision cosmic antiproton spectrum in an unexplored low-energy region; 2) a first detection of cosmic antideuterons, a signature of new physics essentially free of astrophysical background; and 3) leading sensitivity to cosmic antihelium-3. To identify rare antinuclei out of the trillions of particles expected in flight, GAPS pioneers a novel exotic atom-based particle identification technique, which relies on >10 m2 of lithium-drifted silicon (Si(Li)) detectors to capture an incoming antinucleus into an exotic atom and measure the resulting X-ray and nuclear annihilation products. This dissertation details the development, noise performance, and tracking capabilities of the large-area, high-temperature Si(Li) detectors developed for the GAPS mission. Their performance is precisely characterized using a semiconductor noise model and has been shown to be stable over time. In addition, the GAPS sensitivity to cosmic-ray antiprotons is demonstrated in this work using a full instrument simulation, event reconstruction, and models of solar and atmospheric effects. With its large geometric acceptance, GAPS will detect ∼500 cosmic antiprotons per flight, producing a precision spectrum extending to lower energies than any previous measurement. This measurement will be sensitive to models of dark matter, evaporating primordial black holes, and cosmic ray propagation. It will also validate the exotic atom particle identification technique prior to the other GAPS analyses. Beyond local detection in high-altitude particle detectors, cosmic ray populations can be probed remotely via the electromagnetic radiation they produce as they prop-agate through the Galaxy. Recent evidence points to enhanced particle populations of uncertain origin in the Galactic Center region. These unexplained particles challenge the conventional models of cosmic ray propagation used to predict the local fluxes critical for dark matter detection. Using X-ray observations of the giant molecular cloud Sagittarius B2, new upper limits are set on low-energy cosmic ray populations near the Galactic center. The limits are comparable to predictions from hydrogen ionization measurements, supporting the observation of elevated Galactic Center cosmic ray populations. Ph.D. 2023-05-15T19:33:34Z 2023-05-15T19:33:34Z 2022-05 2023-05-10T22:36:00.823Z Thesis https://hdl.handle.net/1721.1/150702 In Copyright - Educational Use Permitted Copyright MIT http://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology |
| spellingShingle | Rogers, Field Rose Applications of X-ray Instrumentation for Dark Matter Searches with Cosmic-ray Antiparticles |
| title | Applications of X-ray Instrumentation for Dark Matter Searches with Cosmic-ray Antiparticles |
| title_full | Applications of X-ray Instrumentation for Dark Matter Searches with Cosmic-ray Antiparticles |
| title_fullStr | Applications of X-ray Instrumentation for Dark Matter Searches with Cosmic-ray Antiparticles |
| title_full_unstemmed | Applications of X-ray Instrumentation for Dark Matter Searches with Cosmic-ray Antiparticles |
| title_short | Applications of X-ray Instrumentation for Dark Matter Searches with Cosmic-ray Antiparticles |
| title_sort | applications of x ray instrumentation for dark matter searches with cosmic ray antiparticles |
| url | https://hdl.handle.net/1721.1/150702 |
| work_keys_str_mv | AT rogersfieldrose applicationsofxrayinstrumentationfordarkmattersearcheswithcosmicrayantiparticles |