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At least 775 records · Page 43

Assembly and Testing of Scintillator Tile Modules for the CMS High-Granularity Calorimeter Upgrade

The High-Granularity Calorimeter (HGCAL), part of the upgrade to the Compact Muon Solenoid (CMS) experiment, employs silicon and scintillator tile modules in the endcaps to maintain detector performance during the High-Luminosity Large Hadron Collider (HL-LHC) era, scheduled to operate from 2030 to 2040. The upgraded calorimeter will provide highly segmented three-dimensional imaging, energy measurements, and precise timing for particle shower reconstruction. Approximately half of the HGCal plastic scintillator tile modules (1,834 total) will be assembled at Fermilab using an automated pick-and-place (PnP) machine. Following assembly, each tile module undergoes quality control (QC) procedures such as electrical validation, thermal testing, and physics validation using cosmic rays. This poster/talk presents the QC procedures and results from the tile module production in 2026, demonstrating the performance and quality of the assembled tile modules.

Bazimya, Jean Luc [Grambling State U.]↗

3D Projection Scintillator Tracker in the DUNE Near Detector

One of the main purposes of the Deep Underground Neutrino Experiment (DUNE) is to measure the CP-violationphase in long-baseline neutrino oscillations with a liquid argon detector of unprecedented size.In order to constrain the systematic uncertainties from the flux, neutrino interaction cross section, energy scale and so on, a near detector is needed to measure the un-oscillated neutrino spectra. In the near detector complex, a three dimensional projection scintillator tracker, also called 3DST, located downstream ofthe liquid-argon detector, is proposed and being studied. 3DST is comprisedof a large number of 1 cm x 1 cm x 1cm scintillator cubes. We expect this tracker to have full solidangle coverage for charged particles, as well as good energy and angular resolutions.3DST provides a unique opportunity of carbon cross section and flux measurements in DUNE,and a great potential of neutron tagging and nuclear effect extraction in the neutrino interactions.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Scintillating Bubble Chambers for Rare Event Searches

The Scintillating Bubble Chamber (SBC) collaboration is developing liquid-noble bubble chambers for the detection of sub-keV nuclear recoils. These detectors benefit from the electron recoil rejection inherent in moderately-superheated bubble chambers with the addition of energy reconstruction provided from the scintillation signal. The ability to measure low-energy nuclear recoils allows the search for GeV-scale dark matter and the measurement of coherent elastic neutrino-nucleus scattering on argon from MeV-scale reactor antineutrinos. The first physics-scale detector, SBC-LAr10, is in the commissioning phase at Fermilab, where extensive engineering and calibration studies will be performed. In parallel, a functionally identical low-background version, SBC-SNOLAB, is being built for a dark matter search underground at SNOLAB. SBC-SNOLAB, with a 10 kg-yr exposure, will have sensitivity to a dark matter–nucleon cross section of 2×10 –42 cm 2 at 1 GeV/c 2 dark matter mass, and future detectors could reach the boundary of the argon neutrino fog with a tonne-yr exposure. In addition, the deployment of an SBC detector at a nuclear reactor could enable neutrino physics investigations including measurements of the weak mixing angle and searches for sterile neutrinos, the neutrino magnetic moment, and the light Z’ gauge boson.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

C$^{7}$LYC: A New Scintillator for Fast Neutron Spectroscopy

The scintillator Cs 2 LiYCl 6 (CLYC) has emerged as a versatile detector for both gammas and neutrons, with excellent pulse shape discrimination. Originally developed as a thermal neutron counter, the discovery of its unexpected and unprecedented ~10% pulse height resolution for fast neutrons in the few MeV range has prompted studies to benchmark its use in low-energy nuclear science and applications. Since the typical long time-of-flight arms are not needed for achieving good energy resolution, geometrical efficiency can be enhanced by positioning the detectors much closer to the target. We have constructed a 16-element array of 1” × 1”7Li-enriched C 7 LYC, to eliminate the dominant peak in the spectrum from thermal neutron capture on 6Li, leaving the energy region above 3 MeV with a clean baseline for fast neutron spectroscopy. We have also procured the first ever 3” × 3” C 7 LYC crystal. Test experiments under way with C 7 LYC include elastic and inelastic neutron scattering cross sections at Los Alamos with a pulsed white neutron source, efficiency measurements using mono-energetic neutron beams up to a few MeV at UMass Lowell, and fission neutron measurements with GRETINA and CHICO detector arrays at Argonne. Beta-delayed neutron spectroscopy experiments have also been initiated at the CARIBU and NSCL facilities, to evaluate C 7 LYC as a possible candidate for auxiliary scintillator arrays for stopped beam physics at the next generation rare isotope accelerators.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Epoxy resins produce improved plastic scintillators

Plastic scintillator produced by the substitution of epoxy resins for the commonly used polystyrene is easy to cast, stable at room temperature, and has the desirable properties of a thermoset or cross-linked system. Such scintillators can be immersed directly in strong solvents, an advantage in many chemical and biological experiments.

Markley, F. W.↗

Scintillation detector for carbon-14

Detector consists of plastic, cylindrical double-wall scintillation cell, which is filled with gas to be analyzed. Thin, inner cell wall is isolated optically from outer (guard) scintillator wall by evaporated-aluminum coating. Bonding technique provides mechanical support to cell wall when device is exposed to high temperatures.

Knoll, G. F.↗

Scintillator handbook with emphasis on cesium iodide

This report provides a background of reasonable depth and reference material on scintillators in general. Particular attention is paid to the cesium iodide scintillators as used in the High Energy Astronomy Observatory (HEAO) experiments. It is intended especially for use by persons such as laboratory test personnel who need to obtain a working knowledge of these materials and their characteristics in a short time.

Tidd, J. L.↗

An empirical model for average F-layer scintillation at VHF/UHF.

An empirical approach to modeling the electron-density irregularities in the F layer that are primarily responsible for amplitude scintillation of VHF/UHF signals has been devised and tested. An irregularity model was postulated as a function of geomagnetic latitude, local time of day, season, and sunspot number. The primary parameters of the irregularities that were postulated were their strength and transverse scale-size. The irregularities were assumed to be aligned along the geomagnetic field, and their axial ratio was taken as constant, as were the height and thickness of the irregular layer. The model is offered as a tool for VHF/UHF communication-systems planning, to the extent that the average value of scintillation in a specified circumstance is of engineering value.

Fremouw, E. J.↗

Interplanetary scintillations of cosmic rays.

Statistically significant broad-band fluctuations or 'scintillations' in the high-energy (T about 1 GeV) cosmic-ray flux observed by neutron monitors are interpreted. A mechanism by which interplanetary magnetic-field fluctuations induce cosmic-ray scintillations is presented and shown to be in quantitative agreement with observation.

Owens, A. J.↗

Impact of scintillation of transionospheric communications

Analyses of AGC analog data from the Small Astronomy Satellite (SAS) at VHF (136 MHz) have shown amplitude fluctuations in the signals received at several equatorial tracking sites operated by NASA. Coincident digital telemetry data, transmitted from SAS at 1 kbps, has also been analyzed. Errors in data are shown to increase markedly for nighttime satellite passes around the periods of the two equinoxes as compared to the errors observed during other periods. This paper establishes the qualitative and quantitative correlations between the ionospheric scintillation phenomenon and the occurrence of errors. Strong time and geographic cause and effect relationships are established by determining the statistical correlation between scintillation indices and bit error rates.

Blank, H. A.↗

Methods of alleviation of ionospheric scintillation effects on digital communications

The degradation of the performance of digital communication systems because of ionospheric scintillation effects can be reduced either by diversity techniques or by coding. The effectiveness of traditional space-diversity, frequency-diversity and time-diversity techniques is reviewed and design considerations isolated. Time-diversity signaling is then treated as an extremely simple form of coding. More advanced coding methods, such as diffuse threshold decoding and burst-trapping decoding, which appear attractive in combatting scintillation effects are discussed and design considerations noted. Finally, adaptive coding techniques appropriate when the general state of the channel is known are discussed.

Massey, J. L.↗

Observations of artificially produced scintillations using satellite transmissions

The ionospheric modification experiment, utilizing a high-powered transmitter, provides an opportunity to study ionospheric irregularities under relatively known conditions. The irregularities were studied by means of transionospheric signals from the polar-orbiting satellite ESSA 8 transmitting at 137 MHz. These observations show that scintillations occur when the satellite to ground station geometry is such that the ray from the satellite passes through the region in the ionosphere under modification. In general, a cut across the illuminated volume is obtained; thus an active region of about 100 km in diameter is indicated. For the most part, the artificial scintillations appear to be similar to those obtained from naturally occurring irregularities, but a systematic change from 3 to 1 sec in the fluctuation period is usually observed as the satellite traverses from the northern to the southern portions of the active region. The change in period appears to be produced by a systematic change in irregularity scale size from about 4 to about 1 km.

Pope, J. H.↗

Effects of multiple scattering on scintillation of transionospheric radio signals

Recent development in the optical scintillation theory has been adapted to the ionospheric geometry in order to study the ionospheric scintillation phenomenon in the presence of multiple scattering. Under approximations well satisfied in typical ionospheres for a frequency above about 20 MHz, the first through fourth moment equations have been derived and some analytic solutions given. The fourth moment equation has also been solved numerically. The numerical results show clearly the occurrence of focusing and saturation phenomena. The new multiple-scatter effects are emphasized.

Liu, C. H.↗