arXiv subjects

M. Oberling

Publications and source records attributed to M. Oberling.

6 recordsLinked to original sources

arXiv2026

Characterization of UV optical components for photon detector calibration in liquid argon TPCs

Large liquid argon time projection chambers (LArTPCs) require stable and well-characterized delivery of ultraviolet (UV) light for in situ calibration of photosensors at cryogenic temperatures. This article reports bench-top and cryogenic measurements of the optical components used in a UV light calibration system, including multi-mode fused-silica fibers, SMA-to-SMA connectors, optical fiber feedthroughs, and light-diffuser assemblies. Light loss in several fiber types and SMA connectors was measured across wavelengths from \qtyrange{275}{970}{nm}. In addition, light-loss measurements of the tested fibers after several liquid-nitrogen thermal cycles showed no statistically significant degradation relative to baseline measurements, and high-rate pulsed exposure (30-90 million pulses from a \qty{275}{nm} LED) likewise showed no measurable aging in jacketed fibers. A compact, palm-sized, 3D-printed PEEK diffuser housing with stacked UV-grade fused-silica diffusers yields Lambertian emission and the most uniform angular distribution. Optical components exhibiting improved UV transmission were deployed successfully in multiple DUNE small- and large-scale prototypes, demonstrating reliable operation of UV light calibration systems. These findings inform component selection and calibration procedures for achieving reliable, uniform UV light delivery in large-scale cryogenic detectors such as DUNE.

physics.ins-det↗

arXiv2023

The Beta-decay Paul Trap Mk IV: Design and commissioning

The Beta-decay Paul Trap is an open-geometry, linear trap used to measure the decays of $^8$Li and $^8$B to search for a tensor contribution to the weak interaction. In the latest $^8$Li measurement of Burkey et al. (2022), $\beta$ scattering was the dominant experimental systematic uncertainty. The Beta-decay Paul Trap Mk IV reduces the prevalence of $\beta$ scattering by a factor of 4 through a redesigned electrode geometry and the use of glassy carbon and graphite as electrode materials. The trap has been constructed and successfully commissioned with $^8$Li in a new data campaign that collected 2.6 million triple coincidence events, an increase in statistics by 30% with 4 times less $\beta$ scattering compared to the previous $^8$Li data set.

physics.ins-det↗

arXiv2021

Design and performance of an in-vacuum, magnetic field mapping system for the Muon g-2 experiment

The E989 Muon $g-2$ experiment at Fermilab aims to measure the anomalous magnetic moment, $a^{}_μ$, of the muon with a precision of 140 parts-per-billion. This requires a precise measurement of both the anomalous spin precession frequency, $ω^{}_a$, and the average magnetic field in terms of the shielded proton Larmor frequency, $ω'^{}_p$. The measurement of $ω'^{}_p$ with a total systematic uncertainty of 70 parts-per-billion involves a combination of various NMR probes. There are 378 probes in fixed locations constantly monitoring field drifts. A water-based probe provides the calibration. A crucial element for the multi-step measurement of $ω'^{}_p$ is the regular mapping of the magnetic field over the muon storage region. The former E821 experiment at Brookhaven employed an in-vacuum field mapping system equipped with 17 NMR probes, which was developed by the University of Heidelberg. We have refurbished and upgraded this system with new probes and electronics. The upgrades include a new communication scheme incorporating time-division multiplexing to separate the important NMR reference clock from the data communication. The addition digitization of the NMR signals replaced the hardware-implemented zero-crossing counting of the E821 system. The digitized signals offer new capabilities in the NMR frequency analysis and its related systematic uncertainties. While the mechanical systems that move the field mapper around the ring have been mostly refurbished, the motion control system was completely replaced with a custom-built electronics centered around a commercial Galil motion controller. Both the field mapping NMR system and its motion control were successfully commissioned at Fermilab and have been in reliable operation during the first data taking periods. This article provides details of the upgrades of the field mapper and its performance.

physics.ins-det↗

arXiv2018

Photon detector system timing performance in the DUNE 35-ton prototype liquid argon time projection chamber

The 35-ton prototype for the Deep Underground Neutrino Experiment far detector was a single-phase liquid argon time projection chamber with an integrated photon detector system, all situated inside a membrane cryostat. The detector took cosmic-ray data for six weeks during the period of February 1, 2016 to March 12, 2016. The performance of the photon detection system was checked with these data. An installed photon detector was demonstrated to measure the arrival times of cosmic-ray muons with a resolution better than 32 ns, limited by the timing of the trigger system. A measurement of the timing resolution using closely-spaced calibration pulses yielded a resolution of 15 ns for pulses at a level of 6 photo-electrons. Scintillation light from cosmic-ray muons was observed to be attenuated with increasing distance with a characteristic length of $155 \pm 28$ cm.

physics.ins-det↗

arXiv2013

Design and Testing of a Wireless Demonstrator for Large Instrumentation Systems

In this proceeding, we report the development of a wireless demonstrator intended to readout instrumentation systems having thousands of channels. A data acquisition system was designed and tested based on compliant implementation of 802.11n based hardware and protocols. This project is for large detectors containing photomultiplier tubes. Both free-space optical and radio frequency techniques were tested for wireless power transfer. The front-end circuitry, including a high-voltage power supply was powered wirelessly, thus creating an all-wireless detector readout. The system was successfully tested as a single detector module, which was powered wirelessly and transmitted data wirelessly. The performance of the prototype system and how a large scale implementation of the system might be realized are described in this proceeding.

physics.ins-det↗

arXiv2013

A Prototype of Wireless Power and Data Acquisition System for Large Detectors

A new prototype wireless data acquisition system has been developed with the intended application to read-out instrumentation systems having a large number of channels. In addition such system could be deployed in smaller detectors requiring increased mobility. The data acquisition and control system is based on 802.11n compliant hardware and protocols. In this paper we describe our case study with a single readout channel performed for a potential large detector containing photomultiplier tubes. The front-end circuitry, including a high-voltage power supply is powered wirelessly thus creating an all-wireless detector readout. The benchmarked performance of the prototype system and how a large scale implementation of the system might be realized are discussed.

physics.ins-det↗