Investigating the slow component of the infrared scintillation time response in gaseous xenon

Xenon is the target material of choice in several rare event searches. The use of infrared (IR) scintillation light, in addition to the commonly used vacuum ultraviolet (VUV) light, could increase the sensitivity of these experiments. Understanding the IR scintillation response of xenon is essential in assessing the potential for improvement. This study focuses on characterizing the time response and light yield (LY) of IR scintillation in gaseous xenon for alpha particles at atmospheric pressure and room temperature. We have previously observed that the time response can be described by two components: one with a fast time constant of O(ns) and one with a slow time constant of O($\mathrm{\mu}$s). This work presents new measurements that improve our understanding of the slow component. The experimental setup was modified to allow for a measurement of the IR scintillation time response with a ten times longer time window of about 3 $\mathrm{\mu}$s, effectively mitigating the dominant systematic uncertainty of the LY measurement. We find that the slow component at about 1 bar pressure can be described by a single exponential function with a decay time of about 850 ns. The LY is found to be (6347 $\pm$ 22 (stat) $\pm$ 400 (syst)) ph / MeV, consistent with our previous measurement. In addition, a measurement with zero electric field along the alpha particle tracks was conducted to rule out the possibility that the slow component is dominated by light emission from drifting electrons or the recombination of electrons and ions.Comment: 9 pages, 4 figure

First time-resolved measurement of infrared scintillation light in gaseous xenon

Xenon is a widely used detector target material due to its excellent scintillation properties in the ultraviolet (UV) spectrum. The additional use of infrared (IR) scintillation light could improve future detectors. However, a comprehensive characterization of the IR component is necessary to explore its potential. We report on the first measurement of the time profile of the IR scintillation response of gaseous xenon. Our setup consists of a gaseous xenon target irradiated by an alpha particle source and is instrumented with one IR- and two UV-sensitive photomultiplier tubes. Thereby, it enables IR timing measurements with nanosecond resolution and simultaneous measurement of UV and IR signals. We find that the IR light yield is in the same order of magnitude as the UV yield. We observe that the IR pulses can be described by a fast and a slow component and demonstrate that the size of the slow component decreases with increasing levels of impurities in the gas. Moreover, we study the IR emission as a function of pressure. These findings confirm earlier observations and advance our understanding of the IR scintillation response of gaseous xenon, which could have implications for the development of novel xenon-based detectors.Comment: 11 pages, 10 figure

5-Fluoro pyrimidines: labels to probe DNA and RNA secondary structures by 1D 19F NMR spectroscopy

19F NMR spectroscopy has proved to be a valuable tool to monitor functionally important conformational transitions of nucleic acids. Here, we present a systematic investigation on the application of 5-fluoro pyrimidines to probe DNA and RNA secondary structures. Oligonucleotides with the propensity to adapt secondary structure equilibria were chosen as model systems and analyzed by 1D 19F and 1H NMR spectroscopy. A comparison with the unmodified analogs revealed that the equilibrium characteristics of the bistable DNA and RNA oligonucleotides were hardly affected upon fluorine substitution at C5 of pyrimidines. This observation was in accordance with UV spectroscopic melting experiments which demonstrated that single 5-fluoro substitutions in double helices lead to comparable thermodynamic stabilities. Thus, 5-fluoro pyrimidine labeling of DNA and RNA can be reliably applied for NMR based nucleic acid secondary structure evaluation. Furthermore, we developed a facile synthetic route towards 5-fluoro cytidine phosphoramidites that enables their convenient site-specific incorporation into oligonucleotides by solid-phase synthesis

The Electron Capture in 163^{163} Ho Experiment - a Short Update

The definition of the absolute neutrino mass scale is one of the main goals of the Particle Physics today. The study of the end-point regions of the β- and electron capture (EC) spectrum offers a possibility to determine the effective electron (anti-)neutrino mass in a completely model independent way, as it only relies on the energy and momentum conservation. The ECHo (Electron Capture in 163Ho) experiment has been designed in the attempt to measure the effective mass of the electron neutrino by performing high statistics and high energy resolution measurements of the 163 Ho electron capture spectrum. To achieve this goal, large arrays of low temperature metallic magnetic calorimeters (MMCs) implanted with with 163Ho are used. Here we report on the structure and the status of the experiment

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Data reduction for a calorimetrically measured

The electron capture in $$^{163}\mathrm {Ho}$$ experiment (ECHo) is designed to directly measure the effective electron neutrino mass by analysing the endpoint region of the $$^{163}\mathrm {Ho}$$ electron capture spectrum. We present a data reduction scheme for the analysis of high statistics data acquired with the first phase of the ECHo experiment, ECHo-1k, to reliably infer the energy of $$^{163}\mathrm {Ho}$$ events and discard triggered noise or pile-up events. On a first level, the raw data is filtered purely based on the trigger time information of the acquired signals. On a second level, the time profile of each triggered event is analysed to identify the signals corresponding to a single energy deposition in the detector. We demonstrate that events not belonging to this category are discarded with an efficiency above 99.8%, with a minimal loss of $$^{163}\mathrm {Ho}$$ events of about 0.7%. While the filter using the trigger time information is completely energy independent, a slight energy dependence of the filter based on the time profile is precisely characterised. This data reduction protocol will be important to minimise systematic errors in the analysis of the $$^{163}\mathrm {Ho}$$ spectrum for the determination of the effective electron neutrino mass

JelleAalbers/blueice: v1.2.0

<ul> <li>Prevent negative rates being passed to Barlow-Beeston equation, and allow per-event weights (#32)</li> <li>Add likelihood that takes coupling as shape parameters (#34)</li> <li>Patch for tests (#37)</li> <li>Use scipy stats for PoissonLL (#40)</li> <li>Do not scale mus when livetime_days is 0 (#41)</li> </ul&gt