PMT Response Research Articles

UNDERSTANDING INDONESIAN CITIZEN'S INTENTIONS TO TAKE PERSONAL PROTECTIVE MEASURES AND FOLLOW A STAY-AT-HOME ORDER TO LIMIT THE SPREAD OF COVID-19

Purpose of the study: This study is aimed to analyze the factors which influence the Intention of the Indonesian public to take personal protective measures and follow the stay-at-home order.
 Methodology: This study was a cross-sectional study, using an instrument of an online questionnaire consisting of 75 questions. A total of 8 hypotheses, built on the foundation of the TPB and PMT model, was tested. The hypotheses were tested using a Structural Equation Modeling (SEM). An online questionnaire was distributed in May 2020 with the target population of the Indonesian public, especially the ones who have a stay-at-home order in their cities.
 Main Findings: All 8 hypotheses were accepted. In the TPB model, It was revealed that Attitude (AT), Subjective Norms (SN), and Perceived Behavioral Control (PBC) significantly affect the public Intention to take personal protective measures. While in the PMT model, Perceived Vulnerability (PV), Perceived Severity (PS), Self-efficacy (SE), Response Efficacy (RE), and Response Cost (RC) have significant relationships with the public Intention to follow a stay-at-home order.
 Applications of this study: Perceived Behavioral Control (PBC) is found to be a powerful predictor of the public Intention to take personal protective measures while for the compliance towards stay-at-home order, Response Efficacy (RE) is found to be a powerful predictor. Therefore, governments and public health organizations are encouraged to focus on giving educations to the public of how a stay-at-home order could be a crucial thing to do in combating COVID-19 promoting to the public that taking personal protective measures is a good thing and not a hard action to do.
 Novelty/Originality of this study: We addressed COVID-19 in a novel way, which is understanding people's underlying psychological factors that influence particular COVID-19 related behaviors. By doing so, this study helps researchers and policymakers in making the appropriate policies and recommendations in slowing the spread of COVID-19.

Gated-Dynode photomultiplier tube assembly for the boronated scintillator detector of the ISS-CREAM experiment

Abstract We present the design of a four-photomultiplier tube (PMT) assembly for measuring light generation in the Boronated Scintillator Detector (BSD) of the Cosmic Ray Energetics And Mass experiment for the International Space Station (ISS-CREAM). The light produced in the scintillator includes a contribution from the capture of thermalized neutrons produced in cosmic ray interactions, as well as delayed fluorescence, in the range of several microseconds following the incident cosmic ray impact. The BSD is held in an insensitive state until a cosmic-ray trigger causes a rapid turn on of the PMTs to detect late light signals, several microseconds after the trigger. The design includes two pulsed high-voltage supplies, which serve to gate the first two dynodes of the Hamamatsu R1924A PMTs used in the assembly. When the dynode gates are held in the “off” state, this scheme is shown to suppress >10 5 photons from injection into the tube’s multiplier stage, while being capable of rapid switching into a stable operating mode in less than 1 μ s. This mitigates any backgrounds from afterpulsing that might otherwise be present in the PMT response following the cosmic ray incidence.

Calibration and performance of the ATLAS Tile Calorimeter during the LHC Run 2

The Tile Calorimeter (TileCal) is the hadronic sampling calorimeter of the ATLAS experiment at the Large Hadron Collider (LHC). TileCal uses iron absorbers and scintillators as active material and it covers the central region | η| < 1.7. Jointly with the other sub-detectors it is designed for measurements of hadrons, jets, tau-particles and missing transverse energy. It also assists in muon identification. TileCal is regularly monitored and calibrated by several different calibration systems: a Cs radioactive source, a laser light system to check the PMT response, and a charge injection system (CIS) to check the front-end electronics. These calibration systems, in conjunction with data collected during proton-proton collisions, Minimum Bias (MB) events, provide extensive monitoring of the instrument and a means for equalizing the calorimeter response at each stage of the signal propagation. The performance of the calorimeter has been established with cosmic ray muons and the large sample of the proton-proton collisions and compared to Monte Carlo (MC) simulations. The response of high momentum isolated muons is also used to study the energy response at the electromagnetic scale, isolated hadrons are used as a probe of the hadronic response. The calorimeter time resolution is studied with multijet events. A description of the different TileCal calibration systems and the results on the calorimeter performance during the LHC Run 2 are presented. The results on the pile-up noise and response uniformity studies are also discussed.

Laboratory tests of the response stability of the ATLAS Tile Calorimeter photomultipliers

High performance stability of the ATLAS Tile Calorimeter is achieved with a procedure including a multi-step calibration. One step of the calibration is based on measurements of the response stability to laser excitation of the PMTs that are used to read out the calorimeter cells. A facility to study the performance of the PMT stability response has been operating in the PISA-INFN laboratories since 2015. Goals of the tests are to study the time evolution of the PMT response in order to reproduce and understand the origin of the response drifts observed with the Tile Calorimeter PMTs during LHC Run I and Run II. A new statistical approach was used to measure the drift of the absolute PMT gain. A new procedure which combines studies of the time evolution of the global PMT responses and of the individual PMT gains was adopted to derive the evolution of the cathode quantum efficiency. The experimental setup of the Pisa facility and the first results obtained by testing about 30 PMTs are presented.

Large photocathode 20-inch PMT testing methods for the JUNO experiment

The 20 kt Liquid Scintillator (LS) JUNO detector is being constructed by the International Collaboration in China, with the primary goal of addressing the question of neutrino mass ordering (hierarchy). The main challenge for JUNO is to achieve a record energy resolution, ∼ 3% at 1 MeV of energy released in the LS, which is required to perform the neutrino mass hierarchy determination. About 20 000 large 20′′ PMTs with high Photon Detection Efficiency (PDE) and good photocathode uniformity will ensure an approximately 80% surface coverage of the JUNO detector. The JUNO collaboration is preparing equipment for the mass tests of all PMTs using 4 dedicated containers. Each container consists of 36 drawers. Each drawer will test a single PMT. This approach allows us to test 144 PMTs in parallel. The primary measurement in the container will be the PMT response to illumination of its photocathode by a low-intensity uniform light. Each of the 20000 PMTs will undergo the container test. Additionally, a dedicated scanning system was constructed for sampled tests of PMTs that allows us to study the variation of the PDE over the entire PMT photocathode surface. A sophisticated laboratory for PMT testing was recently built. It includes a dark room where the scanning station is housed. The core of the scanning station is a rotating frame with 7 LED sources of calibrated short light flashes that are placed along the photocathode surface covering zenith angles from the top of a PMT to its equator. It allows for the testing of individual PMTs in all relevant aspects by scanning the photocathode and identifying any potential problems. The collection efficiency of a large PMT is known to be very sensitive to the Earth Magnetic Field (EMF), therefore, understanding the necessary level of EMF suppression is crucial for the JUNO Experiment. A dark room with Helmholtz coils compensating the EMF components is available for these tests at a JUNO facility. The Hamamatsu R12860 20′′ PMT is a candidate for the JUNO experiment. In this article the container design and mass-testing method, the scanning setup and scanning method are briefly described and preliminary results for performance test of this PMT are reported.

Performances investigation and material selection of PMT magnetic shields for the space experiments with GRIS and PING-M instruments

PMT performances significantly change under the influence of magnetic field. Even the relatively weak geomagnetic field, which typically value is about 0.5 gauss, has an appreciable effect. Gain variations of PMT with 76 mm photocathode diameter may reach 10-20% depending on spatial orientation. Therefore, it is necessary to apply magnetic shields for PMT response stability enhancement. The performances investigation of magnetic shields made of steel, permalloy and amorphous metallic alloy ribbon for PMT with 51 and 76 mm photocathode diameters was carried out. Based on obtained data the choice of magnetic shield was made.

Correction for PMT temperature dependence of the LHCf calorimeters

LHCf is an experiment to measure the very forward production of particles at LHC in order to calibrate the hadronic interaction models used to simulate cosmic-ray air showers. The results obtained from √s = 7 TeV proton-proton collisions have large systematic errors resulting from the energy scale shift of the reconstructed π0 mass. It was found that one of the major sources of this shift is the temperature dependence of the PMT response used in the LHCf detectors. In order to correct the variation of the PMT gain by temperature, two types of temperature variation were considered. As a result, systematic errors resulting from the energy scale of Arm2 was improved by 30 %.

Energy spectrum of cascade showers generated in water by near-horizontal muons

We discuss measuring cascade shower energy using the NEVOD Cherenkov water detector with a spatial lattice of quasi-spherical modules (QSMs). Dense QSM spacing makes it possible to reconstruct a number of cascade particles along the shower axis from the PMT response amplitude. Our cascade curve reconstruction technique is applied to showers generated by near-horizontal high-energy muons selected using the DECOR coordinate detector deployed around NEVOD. The first results from cascade energy spectrum measurements are reported.

Reconstruction of single muon tracks in Cherenkov water detector NEVOD

The technique of single muon track reconstruction in Cherenkov water detector NEVOD is presented. The technique is based on the maximum likelihood method, in which probabilities of PMT response are used. The reconstruction technique has been tested on real experimental events selected by the coordinate detector DECOR. The angular distribution of detected muons has been estimated.

PMT measurements in Antares

The comparison of simulated and real data in the Antares experiment shows some discrepancies. Differences are observed in the charge distribution of background hits, in the trigger efficiency, and in the counting rate of 40K decay induced events. These discrepancies must be understood to improve data analysis. It turns out that most of the simulated/real data mismatch can be explained by a undetailed description of the PMT response in the simulations. PMT parameters such as late pulses, afterpulses and angular acceptance have been reviewed and when necessary measurements of these parameters have been carried out using Antares PMTs and optical modules. In addition a more detailed simulation of the angular acceptance of the Antares optical module has been performed. Results of these studies are presented.

Was the Scanner Calibration Slide used for its intended purpose?

In the article, Scanner calibration revisited, BMC Bioinformatics 2010, 11:361, Dr. Pozhitkov used the Scanner Calibration Slide, a key product of Full Moon BioSystems to generate data in his study of microarray scanner PMT response and proposed a mathematic model for PMT response [1]. In the end, the author concluded that "Full Moon BioSystems calibration slides are inadequate for performing calibration," and recommended "against using these slides." We found these conclusions are seriously flawed and misleading, and his recommendation against using the Scanner Calibration Slide was not properly supported.

The LHCb Hadron Calorimeter

The Hadron Calorimeter of LHCb is a sampling iron-scintillator calorimeter of 5.6 δ1 thickness with structure arranged along the collider beam direction. The light readout is performed with WLS fibers running along the scintillator tile edges. The fast front end electronics allows to digitize events at 40 MHz without dead time. The self-calibration system based on 137Cs radioactive source embedded into the calorimeter structure allows to obtain absolute calibration with precision of about 2It is also equipped with a LED monitoring system, which allows to follow the PMT response variations during physics data taking.

Tracking stars with the fluorescence detector of the Pierre Auger Observatory

Recording tracks of stars traversing the field of view of the Auger's fluorescence detector (FD) is a powerful tool to monitor various FD parameters. Regular control of these tracks would allow checking the telescope's stability during the whole life of the experiment, estimated to be about 20 years. The prototypes used during the engineering array phase have been equipped with a novel optoelectronic system that measured the DC anode current. Dim stars were clearly recorded. We report the results of a reconstruction performed to determine the pointing of a telescope as well as comparisons of a PMT's response to shower and star signals.

Evaluation of candidate photomultiplier tubes for the NOE scintillating fiber calorimeter

Several measurements have been made on different phototubes in order to select the type to be used for the readout system of the NOE magnetized scintillating fiber calorimeter. Characteristics such as gain, linearity, time resolution and cathode uniformity have been examined on several PMT types with standard, fine mesh or channel multiplier structure. The PMT response in the presence of the magnetized calorimeter fringe fields has also been studied. Here we report on the results of these measurements and of the comparisons between the different PMT types.

Results of the R&D program on a magnetized SCIFI calorimeter

A comprehensive R&D program has been developed on a magnetized scintillating fiber imaging calorimeter to be used for hadronic and electromagnetic energy measurements on neutrino events in a LBL ν beam. In this paper we report on the optimization of the optical readout, in particular on gain, linearity, time resolution and cathode uniformity measurements on several PMT types with standard, fine mesh or channel multiplier structure. The PMT response in the presence of the magnetized calorimeter fringe fields has also been studied.