Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userThe Heavy Photon Search beamline and its performance
76
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The Heavy Photon Search (HPS) is an experiment to search for a hidden sector photon, aka a heavy photon or dark photon, in fixed target electroproduction at the Thomas Jefferson National Accelerator Facility (JLab). The HPS experiment searches for the e$^+$e$^-$ decay of the heavy photon with bump hunt and detached vertex strategies using a compact, large acceptance forward spectrometer, consisting of a silicon microstrip detector (SVT) for tracking and vertexing, and a PbWO$_4$ electromagnetic calorimeter for energy measurement and fast triggering. To achieve large acceptance and good vertexing resolution, the first layer of silicon detectors is placed just 10 cm downstream of the target with the sensor edges only 500 $mu$m above and below the beam. Placing the SVT in such close proximity to the beam puts stringent requirements on the beam profile and beam position stability. As part of an approved engineering run, HPS took data in 2015 and 2016 at 1.05 GeV and 2.3 GeV beam energies, respectively. This paper describes the beam line and its performance during that data taking.
rate research
Read More
The Heavy Photon Search (HPS), an experiment to search for a hidden sector photon in fixed target electroproduction, is preparing for installation at the Thomas Jefferson National Accelerator Facility (JLab) in the Fall of 2014. As the first stage of this project, the HPS Test Run apparatus was constructed and operated in 2012 to demonstrate the experiments technical feasibility and to confirm that the trigger rates and occupancies are as expected. This paper describes the HPS Test Run apparatus and readout electronics and its performance. In this setting, a heavy photon can be identified as a narrow peak in the e$^+$e$^-$ invariant mass spectrum, above the trident background or as a narrow invariant mass peak with a decay vertex displaced from the production target, so charged particle tracking and vertexing are needed for its detection. In the HPS Test Run, charged particles are measured with a compact forward silicon microstrip tracker inside a dipole magnet. Electromagnetic showers are detected in a PbW0$_{4}$ crystal calorimeter situated behind the magnet, and are used to trigger the experiment and identify electrons and positrons. Both detectors are placed close to the beam line and split top-bottom. This arrangement provides sensitivity to low-mass heavy photons, allows clear passage of the unscattered beam, and avoids the spray of degraded electrons coming from the target. The discrimination between prompt and displaced e$^+$e$^-$ pairs requires the first layer of silicon sensors be placed only 10~cm downstream of the target. The expected signal is small, and the trident background huge, so the experiment requires very large statistics. Accordingly, the HPS Test Run utilizes high-rate readout and data acquisition electronics and a fast trigger to exploit the essentially 100% duty cycle of the CEBAF accelerator at JLab.
We have developed a Multi-Pixel Photon Counter (MPPC) for the neutrino detectors of T2K experiment. About 64,000 MPPCs have been produced and tested in about a year. In order to characterize a large number of MPPCs, we have developed a system that simultaneously measures 64 MPPCs with various bias voltage and temperature. The performance of MPPCs are found to satisfy the requirement of T2K experiment. In this paper, we present the performance of 17,686 MPPCs measured at Kyoto University.
We present the design and characterization of a large-area Cryogenic PhotoDetector (CPD) designed for active particle identification in rare event searches, such as neutrinoless double beta decay and dark matter experiments. The detector consists of a $45.6$ $mathrm{cm}^2$ surface area by 1-mm-thick $10.6$ $mathrm{g}$ Si wafer. It is instrumented with a distributed network of Quasiparticle-trap-assisted Electrothermal feedback Transition-edge sensors (QETs) with superconducting critical temperature $T_c=41.5$ $mathrm{mK}$ to measure athermal phonons released from interactions with photons. The detector is characterized and calibrated with a collimated $^{55}$Fe X-ray source incident on the center of the detector. The noise equivalent power is measured to be $1times 10^{-17}$ $mathrm{W}/sqrt{mathrm{Hz}}$ in a bandwidth of $2.7$ $mathrm{kHz}$. The baseline energy resolution is measured to be $sigma_E = 3.86 pm 0.04$ $(mathrm{stat.})^{+0.23}_{-0.00}$ $(mathrm{syst.})$ $mathrm{eV}$ (RMS). The detector also has an expected timing resolution of $sigma_t = 2.3$ $mumathrm{s}$ for $5$ $sigma_E$ events.
A picoammeter system has been developed and engineering. It consists in a current-voltage converter, based on an operational amplifier with very low input current, a high precision ADC, a radio controlled data acquisition unit and the computer-based control, visualization and storage. The precision is of the order of a tenth of picoampers and it can measure currents between electrodes at potentials up to 8 kV. The system is battery powered and a number of strategies have been implemented to limit the power consumption. The system is designed for multichannel applications, up to 256 parallel channels. The overall implementation is cost-effective to make the availability of multichannel setups easily affordable. The design, implementation and performance of the picoammeter system are described in detail as well as a an application: the measurement of ion backflow in MPGD-based photon detectors.
A high-pressure xenon gas time projection chamber, with a unique cellular readout structure based on electroluminescence, has been developed for a large-scale neutrinoless double-beta decay search. In order to evaluate the detector performance and validate its design, a 180~L size prototype is being constructed and its commissioning with partial detector has been performed. The obtained energy resolution at 4.0~bar is 1.73 $pm$ 0.07% (FWHM) at 511 keV. The energy resolution at the $^{136}$Xe neutrinoless double-beta decay Q-value is estimated to be between 0.79 and 1.52% (FWHM) by extrapolation. Reconstructed event topologies show patterns peculiar to track end-point which can be used to distinguish $0 ubetabeta$ signals from gamma-ray backgrounds.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
