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Brian Doty

Publications and source records attributed to Brian Doty.

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The Solar Neutrino and Astro-Particle PhYsics (SNAPPY) CubeSat Development

The SNAPPY CubeSat, which was launched May 3, 2026, will demonstrate and space qualify the nuSol neutrino-detection technology. The nuSol technology detects solar neutrinos using a gallium isotope which decays by emitting two particles spaced apart in time; this allows differentiating neutrino events from cosmic rays. In the NIAC Phase II project review in 2021, concept and science were determined to be feasible; however, two precursor studies were recommended before pursuing a full mission study. These studies were to characterize the true deep-space background for the detector's gallium double-pulse signal and to collect a statistically significant number of double-pulse events demonstrating that fast electronics can reliably select and analyze this signal. To test double-pulse signals in space, a NIAC Phase III funded building a 3U CubeSat carrying a 0.1-kg gallium-aluminum-gadolinium-garnet detector housed within an active veto array and shielding. Because the detector requires deep-space-like conditions, the CubeSat is designed for a polar low-Earth orbit at 450 km or higher altitude, collecting data over the Earth's poles above the Van Allen belts. The detector is highly sensitive, with roughly 7-percent energy resolution, with active veto shielding and passive shielding using a patented tungsten-powder and epoxy mixture that disintegrates upon atmospheric reentry. SNAPPY enables additional science during the extended mission phase of year two operations. These include measurements of solar wind particle density and energy spectra with particle identification of electrons, protons, and alpha particles; detection of very low-energy gamma rays from galactic gamma-ray bursts without directionality.

physics.ins-det

SNAPPY CubeSat Control Script Generation and Data File Processing

This is a document discussing the creation and usage of a server system dedicated to retrieving, processing, and storing data generated from the Solar Neutrino and Astro-Particle PhYsics (SNAPPY) CubeSat by the nuSOL (Neutrino Solar Orbiting Laboratory) Project. On a traditional desktop computer with CERN's ROOT and PostgreSQL software installed, and with a file system on two mirrored drives, it is possible to automatically process and organize incoming data, along with keeping a database to record each incoming file along with a command record. In addition to this, an application was created to provide a Graphical User Interface to assist with creating commands to communicate with the CubeSat. With that said, there are still plenty of plans to improve the software, mainly providing an automatic emailing system to notify team members when they are not around the server.

astro-ph.IM

Segment Geometry Optimization and Prototype Studies of a Multi-Coincidence GAGG Solar Neutrino Detector

A GAGG detector capable of dissecting a multi-coincidence solar neutrino interaction on ${}^{71}$Ga is under development for potential space-based applications. We identify three distinct detection signatures when ${}^{71}$Ge$^*$ is produced, two of which are significantly delayed in time and could be detected within a single large GAGG volume. Further optimizations can be made by optically isolating smaller segments of GAGG to maximize the probability of a spatial separation between the prompt/delayed signals. We construct and test prototype GAGG detectors capable of sub 7% energy resolution @ ${}^{137}$Cs and reliable detection of spatially-separated ${}^{57}$Co double-pulse decays.

hep-ex

New methods of neutrino and anti-neutrino detection from 0.115 to 105 MeV

We have developed a neutrino detector with threshold energies from ~0.115 to 105 MeV in a clean detection mode almost completely void of accidental backgrounds. It was initially developed for the NASA $\nu$SOL project to put a solar neutrino detector very close to the Sun with 1,000 to 10,000 times higher solar neutrino flux than on Earth. Similar interactions have been found for anti-neutrinos, which were initially intended for Beta decay neutrinos from reactors, geological sources, or for nuclear security applications. These techniques work at the 1 to 100 MeV region for neutrinos from the ORNL Spallation Neutron Source or low energy accelerator neutrino and anti-neutrino production targets less than $\sim$100 MeV. The identification process is clean, with a double pulse detection signature within a time window between the first interaction producing the conversion electron or positron and the secondary gamma emission 100 ns to ~1 $\mu$s, which removes most accidental backgrounds. These new modes for neutrino and anti-neutrino detection of low energy neutrinos and anti-neutrinos could allow improvements to neutrino interaction measurements from an accelerator beam on a target.

physics.ins-det

Gamma Ray Detection Efficiency of GAGG Crystal Scintillator Using Three Tagged Gamma Ray Techniques

A CubeSat with a prototype scintillating detector with a sensitive volume of GAGG crystal is being developed with a possible launch date of 2025. Its purpose is to characterize the background signals that mimic the neutrino interaction that the nuSOL (Neutrino Solar Orbiting Laboratory) team is looking for. An important part of the characterization of the backgrounds and the expected real signal is understanding the gamma ray detection efficiency of the prototype detector when compared to simulations performed in Geant4. To this end we have used three techniques to do a measurement of the gamma ray efficiency compared to simulation. The first is using electron capture sources that emit an X-ray before prompt emission of a de-excitation gamma ray, specifically Zn-65 and Mn-54. The second is using a beta + decay source wherein a positron annihilates on an atomic shell electron producing two back-to-back 511 keV gammas followed promptly by a de-excitation gamma, specifically Na-22. The third is using a gamma cascade of two near-simultaneous de-excitation gammas from the same nucleus, specifically from Co-60 decay.

physics.ins-det

New lower background and higher rate technique for anti-neutrino detection using Tungsten 183 Isotope

Low energy anti-neutrinos detected from reactors or other sources have typically used the conversion of an anti-neutrino on Hydrogen, producing a positron and a free neutron. This neutron is subsequently captured on a secondary element with a large neutron capture cross section such as gadolinium or cadmium. We have studied the anti-neutrino conversion and suggest other elements that have a comparable cross section for anti-neutrino reactions. With most neutron captures on gadolinium, it is possible to get two or three delayed gamma signals of known energy to occur. Experiments like ATLAS can make measurements with timing on the order of 25 ns. With electronics like these, this leads to the possibility of having a triple delayed coincidence using the positron annihilation on atomic shell electrons as the starting signal. We have also found an isotope of tungsten, $^{183}$W that offers a large anti-neutrino interaction cross section of $1.19 \times 10^{-46}$ m$^2$ and an anti-neutrino threshold energy for the production of the ground state at 2.094 MeV and the production of the first excited state at 2.167 MeV. This reaction makes a nuclear m1 excited state of $^{183}$Ta$^*$ that emits a signature secondary gamma pulse of 73 keV with a 106 ns half-life. This offers a new delayed coincidence technique that can be used to identify anti-neutrinos with lower background noise. This allows for less shielding than required for modern inverse beta decay detectors.

physics.ins-det