Search

Designs of hodoscopes of nuclear fragments based on quartz and scintillation plates with light pickup by silicon avalanche photodiodes are described. Hodoscopes are planned for use in the BM@N experiment for registration of heavy nuclear fragments near the axis of the heavy ion beam. The results of measurements of light yields in detector elements based on quartz and scintillation plates on the electron beam of the synchrotron "Pakhra" (LPI) are presented. The measured nonuniformity of the light collection shows that readout from both sides of hodoscope detector elements is needed.

A universal model is considered for a scintillation muon hodoscope (MH) to be used in the muonography of large objects. Muon tracks are registered by a multilayer assembly of narrow long scintillation strips with light collected by optical fibers on silicon photomultipliers. Characteristics of the scintillation MH are determined and its model in the Geant4 software package is described. The model strip’s parameters are calibrated on the basis of experimental data.

Cosmic ray muons are widely used to study the internal structure of different large-scale natural and artificial objects. The technique is called muonography in analogy with radiography. In this work, results are presented from tests of different elements of the detecting system of the muon hodoscope under development at MEPhI.

We present a study of the radiation field at various locations in the ATLAS experiment, using compact detector systems based on pixelated silicon sensors assembled with Timepix readout chips. The hodoscope design of the ATLAS-Timepix (TPX) detectors includes neutron converters in between two sensors, allowing the characterization of both neutron and charged particle fields on a track by track basis. Thermal and fast neutrons are discriminated by segmenting the sensor area with dedicated sensitive materials. Using specific pattern recognition algorithms, clusters from electrons and photons above ~10 keV, minimum ionizing particles (MIPs), and highly ionizing particles are classified. A coincidence method using the time-over-threshold mode of the chip is developed to extract stopping power and directional information of energetic charged particles. Thermal neutron fluences are obtained for each ATLAS-TPX unit, illustrating the effect of detector material and shielding in the experimental cavern. Reconstructed trajectories of energetic charged particles point out radiation coming from the interaction point and other hot spots.

The Baksan Underground Scintillation Telescope (BUST) is located in the North Caucasus in an underground laboratory at an effective depth of 850 m.w.e. The BUST began working in 1977, and the installation is still in operation. The successful design of the BUST allows it to be used to solve a number of problems in astrophysics and particle physics. The new data acquisition system is designed to record and analyze experimental data with greatly improved measurement characteristics of digital and analog signals. The data acquisition system is based on the VME interface and provides complete compatibility with existing low-level BUST recording electronics. The hodoscope of pulse channels was completely redeveloped and implemented on field-programmed gate array (FPGA) and LVDS chips.

This work describes the theoretical and experimental performances of four alternatives to the original Hornyak Button-type device that was used in the construction of the Transient Reactor Test (TREAT) Facility hodoscope. The alternatives considered differ in geometry, construction and detection materials to improve performance while decreasing some of the negative aspects of the original device. A Geant4 model of the original Hornyak Button was developed as a benchmark to validate the physics modeled, which agreed well with the reported values. The four alternatives considered were (1) a homogenized ZnS:Ag/PMMA rectangular bar outfitted with silicon photomultipliers (SiPMs), (2) a layered ZnS:Ag/PMMA rectangular bar detector also outfitted with SiPMs, (3) a microstructured neutron detector (MSND) backfilled with hydrogenous material and (4) a pressurized, organic gaseous scintillator. In two scintillation devices, SiPMs were considered as a replacement for photomultiplier tubes for greater light collection. These alternatives were considered as they each had the potential to provide better signal-to-noise ratios, reduce Cerenkov light production, increase detection efficiency, and/or improve neutron-to-gamma discrimination. At comparable lengths, the layered design has been experimentally determined to yield an efficiency of 1.3% (the Hornyak button exhibits 0.4%), while studies on the performances of the other detectors are still underway.

The design and performance of a new front-end acquisition system is presented in this paper. It was developed to be used with muon array with resistive plate chamber (RPCs) for tagging air showers (MARTA’s) RPC detectors that measure the muonic component of cosmic ray air showers. The system is hybrid and capable of counting active channels and performing a charge measurement. It is low power (1.43 W per 64 channels), compact ( $21.6 \times 14.4\,\,\mathrm {cm^{2}}$ per 64 channels), stable, and reliable to comply with the strict demands of field operation associated with experiments that measure air showers. The front-end is based on an application-specified integrated circuit [Multi Anode Read-Out Chip (MAROC)] with 64 input channels, which is responsible for the digitization of the RPC signals. While a simple threshold measurement is applied after a fast shaper to count particles, the charge measurement is performed by an analog to digital converter that reads the peak of a slow shaper. An field-programmable gate array is responsible for control of all the digital part which includes storing the MAROC outputs and sending them to a Central Unit [via low voltage differential signal (LVDS)] or PC (via USB). Both the count and charge measurement performance are assessed. The threshold efficiency curve is measured for different temperatures. For all the conditions tested, the efficiency is 100% for charges higher than 52 fC. The overall efficiency to detect muons is studied by placing an RPC between a hodoscope and comparing the efficiency of the front-end with another established data acquisition system. The efficiency results are consistent within the statistical uncertainties of the measurements showing that the MARTA front-end does not introduce unwanted inefficiencies in the setup. The charge measurement is tested in the laboratory using a signal generator. Different shaping conditions and input charges are used to study the waveform of the slow shaper. A linear dependence between input charge and the value measured by the MAROC was found and taken as the calibration curve for the particular channel tested.

The GlueX experiment at Jefferson Lab has been designed to study photoproduction reactions with a 9-GeV linearly polarized photon beam. The energy and arrival time of beam photons are tagged using a scintillator hodoscope and a scintillating fiber array. The photon flux is determined using a pair spectrometer, while the linear polarization of the photon beam is determined using a polarimeter based on triplet photoproduction. Charged-particle tracks from interactions in the central target are analyzed in a solenoidal field using a central straw-tube drift chamber and six packages of planar chambers with cathode strips and drift wires. Electromagnetic showers are reconstructed in a cylindrical scintillating fiber calorimeter inside the magnet and a lead-glass array downstream. Charged particle identification is achieved by measuring energy loss in the wire chambers and using the flight time of particles between the target and detectors outside the magnet. The signals from all detectors are recorded with flash ADCs and/or pipeline TDCs into memories allowing trigger decisions with a latency of 3.3 $\mu$s. The detector operates routinely at trigger rates of 40 kHz and data rates of 600 megabytes per second. We describe the photon beam, the GlueX detector components, electronics, data-acquisition and monitoring systems, and the performance of the experiment during the first three years of operation., Comment: Accepted by Nuclear Instruments and Methods A, 78 pages, 54 figures

The CABRI experimental pulse reactor, located at the Cadarache nuclear research center, southern France, is devoted to the study of Reactivity Initiated Accidents (RIA). When the thermal-hydraulic conditions representative of a pressurized water nuclear reactor are reached (mostly temperature, pressure and flowrate conditions), a fuel test rod is submitted to a power excursion, triggered by the specific 3He reactivity injection system, in order to simulate a control rod ejection accident. The experiment, managed by IRSN, aims at studying both the fuel and cladding behavior of the test rod placed into the center of the reactor during the power excursion. Several test rods pre-irradiated in pressurized nuclear power plants and with different characteristics (burn up, cladding material, fuel type, Zirconia thickness) are considered for the programs performed in the CABRI reactor. Physical phenomena occurring during the power transient are monitored by various measuring systems designed or operated by IRSN. Each system provides information linked with the different phases of the experiment. Three main measuring systems will be considered in this paper: • The test devices, a sample holder that is also implemented with almost fifty sensors used to monitor the environmental parameters in the test channel such as temperature and pressure, and to control the rod behavior during the test sequence; • The Hodoscope, an online fuel motion measurement system, which aims at analyzing the fuel motion deduced from the detection of fast neutrons emitted by the test rod, with a time step of 1ms during the transient; • The IRIS facility, conceived to perform X-ray radiography and tomography imaging before and after a power transient thanks to a linear electron accelerator, as well as quantitative gamma scanning analyses. During the experimental sequence, different events are recorded. This paper focuses on a cladding failure that occurred during the transient and that can be revealed by the three systems mentioned above. The test device instrumentation allows to determine the timing of the failure and to analyze its consequences in the vicinity of the test rod from a thermal and hydraulic point of view, while the hodoscope measures fuel elongation and relocation during the power excursion. The IRIS facility, then, helps to confirm the failure, its location and its extent. These three systems are complementary and they allow the analysis of the same event from different perspectives. Their combination will ease the interpretation of the events in the next steps for the test results analysis. The study case taken into account in this paper concerns nuclear fuel after three irradiation cycles in a commercial PWR.

A beam tagging hodoscope prototype made of squared 1 mm$^2$ fibers arranged in two perpendicular planes and coupled to multi-anode photomultipliers has been studied using 65 MeV proton as well as 95 MeV/u $^{12}$C beams at various intensities. This hodoscope successfully provided 2D images of proton beams with a detection efficiency larger than 98 % with logical OR condition between the two fiber planes. The detection efficiency with a coincidence between the two planes is close to 75 % for beam intensities up to $\sim1$ MHz. Moreover, the timing resolution is around 1.8 ns FWHM. Overall, the performances show that such a technology is viable for beam monitoring during hadrontherapy., 17 pages, 18 figures

This document presents the technical layout and the performance of the CLAS12 Forward Tagger (FT). The FT, composed of an electromagnetic calorimeter based on PbWO4 crystals (FT-Cal), a scintillation hodoscope (FT-Hodo), and several layers of Micromegas trackers (FT-Trk), has been designed to detect electrons and photons scattered at polar angles from 2 ∘ to 5 ∘ and to meet the physics goals of the hadron spectroscopy program and other experiments running with the CLAS12 spectrometer in Hall B.

In order to fully exploit the ballistic potential of particle therapy, we propose an online range monitoring concept based on high-resolution Time-Of-Flight (TOF)-resolved Prompt Gamma (PG) detection in a single proton counting regime. In a proof of principle experiment, different types of monolithic scintillating gamma detectors are read in time coincidence with a diamond-based beam hodoscope, in order to build TOF spectra of PG generated in a heterogeneous target presenting an air cavity of variable thickness. Since the measurement was carried out at low beam currents ($, Comment: 17 pages, 18 figures

The performance of traditional Hornyak buttons and two proposed variants for fast-neutron hodoscope applications was evaluated using Geant4. The Hornyak button is a ZnS(Ag)-based device previously deployed at the Idaho National Laboratory’s TRansient REActor Test Facility (better known as TREAT) for monitoring fast neutrons emitted during pulsing of fissile fuel samples. Past use of these devices relied on pulse-shape discrimination to reduce the significant levels of background Cherenkov radiation. Proposed are two simple designs that reduce the overall light guide mass (here, polymethyl methacrylate or PMMA), employ silicon photomultipliers (SiPMs), and can be operated using pulse-height discrimination alone to eliminate background noise to acceptable levels. Geant4 was first used to model a traditional Hornyak button, and for assumed, hodoscope-like conditions, an intrinsic efficiency of 0.35% for mono-directional fission neutrons was predicted. The predicted efficiency is in reasonably good agreement with experimental data from the literature and, hence, served to validate the physics models and approximations employed. Geant4 models were then developed to optimize the materials and geometries of two alternatives to the Hornyak button, one based on a homogeneous mixture of ZnS(Ag) and PMMA, and one based on alternating layers of ZnS(Ag) and PMMA oriented perpendicular to the incident neutron beam. For the same radiation environment, optimized, 5-cm long (along the beam path) devices of the homogeneous and layered designs were predicted to have efficiencies of approximately 1.3% and 3.3%, respectively. For longer devices, i.e., lengths larger than 25 cm, these efficiencies were shown to peak at approximately 2.2% and 5.9%, respectively. Moreover, both designs were shown to discriminate Cherenkov noise intrinsically by using an appropriate pulse-height discriminator level, i.e., pulse-shape discrimination is not needed for these devices.

The New CHOD is a scintillation hodoscope with a pad structure featuring a total of 148 counters. The signal from each pad is read out using wavelength-shifting fibers and two or four SensL SiPMs with a sensitive area of 3 × 3 mm2. This photodetector has 4774 pixels 35 × 35 μm2 in size. The key parameters (photon detection efficiency, dark current, crosstalk, and gain) were measured for 500 SiPMs.

A Compact Spectrometer for Heavy IoN Experiments (CSHINE) has been recently built for the studies of heavy ion reactions at intermediate energies. CSHINE consists of a Si-Si-CsI telescope array and a parallel plate avalanche counter (PPAC) array. Each telescope consists of a thin single-sided silicon strip detector and a thick double-sided silicon strip detector backed by a 3 × 3 CsI(Tl) crystal hodoscope . The thicknesses of the silicon detectors are optimized in order to identify various types of light charged particles in a wide energy range. PPAC is a large-area two-dimensional position-sensitive gas detector, which records fission fragments with the intrinsic efficiency of approximately 100% but filters out light charged particles at properly selected working conditions. In the phase-II run, four Si-Si-CsI telescopes and three PPACs have been installed and operated in the beam experiment with 25 MeV/u Kr+Pb reactions. Particle identification for isotopes from Hydrogen to Boron has been achieved with the Si-Si-CsI telescopes, while excellent timing and position resolution have been achieved with the PPACs.

Artificial Intelligence (AI) algorithms have shown their capability to complement human analysis in the understanding of complex phenomena. Their advantages essentially rely on the flexibility of their construction that allows capturing complex relationships between inputs and outputs of a problem and also on their ability to adapt themselves via a learning phase to the available information. As a result, AI is widely used in many scientific fields and especially those related to the nuclear industry. This work deals an application of AI based on several classical machine learning approaches for the study of Reactivity Initiated Accidents (RIA) in the CABRI experimental pulse reactor located at the Cadarache research center, southern France. We focus on the interpretation of the fuel rod behaviour during the power pulse using the online fuel motion monitoring system called the hodoscope . The objective of this paper is to investigate how AI algorithms can be used for the automatic detection of a generic fuel delocalization from the signals recorded by the hodoscope.

International audience; A collimated gamma camera consisting of a multi-parallel slit collimator and an absorber has been proposed to be coupled with a beam hodoscope for ion-range verification during hadrontherapy by means of Prompt Gamma (PG) detection. The beam hodoscope associated to this gamma camera provides information on the incident ion position and arrival time to improve the PG image reconstruction and time-of-fight measurement. The data acquisition (DAQ) system of this detection system has been designed to meet the specifications: 1 µs trigger delay, timing resolution < 1 ns, 100 kHz trigger rate and a few 108 bits/s final data rate. It consists of 8 frond-end (FE) readout boards of two types: 2 boards for the hodoscope and 6 boards for the absorber. These FE boards have the same basic structure, consisting of a FPGA, an optical transceiver and a multi-channel analog readout module. The main difference between the two types of FE boards is that the former incorporates two 32-channel readout ASICs, and the latter employs 8-channel DRS4 (Domino Ring Sampling) mezzanines (3 for each board). In addition the system also includes a data-communication module, mainly composed of a data transmission control board called AMC40 which has a 1-Gbit/s Ethernet link for PC connection and 36 available 3 Gbit/s optical links to FE readout boards. On the other hand, we have developed the firmware of every FE board FPGA to realize several multi-phase clock time-to-digital (TDC) convertors: one for the system synchronization and the others for particle’s arrival time tagging. For the 2 hodoscope FE boards, FPGA firmware implementation includes an adjustable-depth measured-data buffer, an histogram-based fast time-of-flight estimation, coincidence-event searching and data zero-suppression. Our designed DAQ system has recently been tested successfully with a reduced-size collimated camera configuration coupled with the beam hodoscope in the Mediterranean proton therapy Institute in Nice (France).

The Transient Reactor Test (TREAT) Facility at Idaho National Laboratory is being restored to support the mission of advanced reactor and fuel development in the United States. A key part of this restoration is the fast neutron hodoscope which images the fuel tested during extreme transient conditions. Traditionally, this testing has been done with ZnS(Ag)-based proton recoil scintillators (PRS) coupled to photomultiplier tubes (PMTs). Recently, silicon photomultipliers (SiPMs) have emerged as a new candidate to replace PMTs in this application. This work develops, tests, and evaluates a SiPM-based PRS detector for incorporation into the updated fast neutron hodoscope, also known as the Fuel Motion Monitoring System (FMMS). The primary characteristics to be optimized are the gamma rejection and neutron detection efficiency of the detector, which will be done using a pulse shape discrimination (PSD) technique. Five types of SiPMs are tested and compared using standard PSD figures of merit, and the Hamamatsu 6075 is selected as the ideal SiPM. PSD performance for the Hamamatsu 6075 SiPM with the PRS detector is also characterized as a function of temperature. Finally, the gamma rejection and neutron detection efficiency are characterized for this SiPM and benchmarked to the traditional PMT-based PRS detectors. Both light sensors exhibit excellent gamma rejection and neutron detection efficiency. However, the SiPM-based detectors exhibit a greater ability to discriminate neutrons from gammas based only on pulse height which is important in operating at high count rates. This motivates the development of a SiPM-based PRS detector in a fully self-contained assembly to test directly with TREAT or in similar environments.

The increased luminosity of the HL-LHC requires a new, high rate capable, high resolution detector technology for the inner end cap of the muon spectrometer of the ATLAS experiment. For this purpose the Micromegas technology is chosen as precision tracker. The SM2 modules are 2 m^2-sized Micromegas quadruplets and cover about 25 percent of the active Micromegas area of the New Small Wheels. This large size requires a sophisticated construction to provide a spatial resolution better than 100 micrometer. The first prototype SM2 module was investigated using 120 GeV pions and muons at SPS/CERN as well as with cosmic muons in a precision facility. The spatial resolution of the SM2 detector is analyzed using two different methods. A charge weighted position reconstruction, the so-called centroid method, achieves a spatial resolution of about 80 mirometer for perpendicular particle incident. A drift time evaluation of the strip readout, yields a similar resolution for tracks inclined to the active area of the module. To investigate and calibrate the full active area of SM2 quadruplets the LMU Cosmic Ray Facility (CRF) is used. Two ATLAS Monitored Drift Tube chambers (MDT) provide precise muon track information in the order of 100 micrometer. A trigger hodoscope segments the position information in 10 cm bands along the wires of the MDTs. The angular acceptance of the CRF is between -30 degree and +30 degree to the zenith angle over an area of about 8 m^2. We present results for the first prototype SM2 quadruplet with 12288 channels read out fully by 96 APVs connected to six FEC cards. The segmentation of the active area enables a detailed analysis of local detector properties, for example geometrical quality, homogeneity in efficiency, in pulse height and in spatial resolution.

A prototype detector, called FLASH (Fast Light Acquiring Start Hodoscope), was built to provide precise Time-of-Flight (TOF) measurements and reference timestamps for detector setups at external beam lines. Radiator bars, made of synthetic fused silica, were coupled to a fast MCP-PMT with 64 channels and read out with custom electronics using Time-over-Threshold (TOT) for signal characterization. The TRB3 system, a high-precision TDC implemented in an FPGA, was used as data acquisition system. The performance of a system consisting of two FLASH units was investigated at a dedicated test experiment at the Mainz Microtron (MAMI) accelerator using its 855 MeV electron beam. The TOT measurement enabled time walk corrections and an overall TOF resolution of ∼70 ps could be achieved which translates into a resolution of ∼50 ps per FLASH unit. The intrinsic resolution of the frontend electronics including the TDC was measured to be less than 25 ps.

The Muon Scattering Experiment at the Paul Scherrer Institut uses a mixed beam of electrons, muons, and pions, necessitating precise timing to identify the beam particles and reactions they cause. We describe the design and performance of three timing detectors using plastic scintillator read out with silicon photomultipliers that have been built for the experiment. The Beam Hodoscope, upstream of the scattering target, counts the beam flux and precisely times beam particles both to identify species and provide a starting time for time-of-flight measurements. The Beam Monitor, downstream of the scattering target, counts the unscattered beam flux, helps identify background in scattering events, and precisely times beam particles for time-of-flight measurements. The Beam Focus Monitor, mounted on the target ladder under the liquid hydrogen target inside the target vacuum chamber, is used in dedicated runs to sample the beam spot at three points near the target center, where the beam should be focused., Fixed typos, added references, and rephrased some sections to be clearer. Changed numbering of tables and figures in Appendix

A cluster type NEVOD-EAS setup is being constructed by the National Research Nuclear University MEPhI on the basis of the Unique Scientific Facility “Experimental Complex NEVOD”. The NEVODEAS setup is intended for the detection of extensive air showers (EASs) with energies in the region of the knee in the energy spectrum of primary cosmic rays (1015–1017 eV). The key elements of the setup are 192 particle detectors for EAS electron–photon and muon components. These detectors are composed of NE102A organic scintillators and Philips XP3462 photomultiplier tubes enclosed in pyramidal steel cases. The techniques used to investigate the characteristics of scintillator plates, photomultiplier tubes, and NEVOD-EAS detectors, as well as the results of this investigation, are discussed. All measurements have been taken using special testing facilities and the precision URAGAN muon hodoscope, with which it is possible to comprehensively investigate the nonuniformity of light collection in the detector (the dependence of the detector response on the location of the passage of a charged particle through its operating volume).

This paper describes the design, simulation, and prototyping of a scintillating-fiber (SciFi) beam hodoscope that enables real-time particle identification, momentum and position determination, and flux counting in a low-momentum mixed beam of pions, electrons and muons for the MUon-proton Scattering Experiment (MUSE) at the Paul Scherrer Institute (PSI), Switzerland. The experimental demands and conceptual design are discussed, including the mixing scheme used to suppress cross-talk between adjacent fibers. A comparison between different types of fibers is given. The timing resolution for 1 plane of SciFis is 0.40 ± 0.05 ns , and for 2 fiber planes in coincidence, it is 0.27 ± 0.03 ns . The detection efficiency when at least two planes are required to fire is 98%.

The SeaQuest experiment (Fermilab E906) detects pairs of energetic {\mu}+ and {\mu}- produced in 120 GeV/c proton-nucleon interactions in a high rate environment. The trigger system consists of several arrays of scintillator hodoscopes and a set of field-programmable gate array (FPGA) based VMEbus modules. Signals from up to 96 channels of hodoscope are digitized by each FPGA with a 1-ns resolution using the time-to-digital convertor (TDC) firmware. The delay of the TDC output can be adjusted channel-by-channel in 1-ns steps and then re-aligned with the beam RF clock. The hit pattern on the hodoscope planes is then examined against pre-determined trigger matrices to identify candidate muon tracks. Information on the candidate tracks is sent to the 2nd-level FPGA-based track correlator to find candidate di-muon events. The design and implementation of the FPGA-based trigger system for SeaQuest experiment are presented., Comment: 12 pages, 9 figures

The contribution describes the design of Timepix-based hodoscope for cubesat applications, such as PilsenCube2, developed by the University of West Bohemia. The hodoscope is composed of two Timepix detectors with silicon thickness of 300 μ m , placed in back-to-back arrangement and rotated relative to each other by 90°, forming a telescope set-up. A copper separator is placed between two detectors to distinguish electrons and protons. The payload hardware and firmware are designed to support single detector operation as well as dual detector operation mode, in which particle coincidence detection is possible. The hodoscope electronic has been designed with respect to harsh radiation environment present in LEO (Low Earth Orbit). The device involves independent radiation hardened power supplies, including bias high voltage supply (up to 250 V) and auxiliary threshold reference DAC for each Timepix detector. Considering highly limited achievable data throughput between the CubeSat and the ground control station, advanced on-board data processing has been developed to reduce the size of transmitted data. The on-board data processing is provided by the radiation hardened SoC (System on Chip) Smartfusion2.

Modern nuclear physics experiments demand for new high-resolution and high-versatility detectors for the reconstruction of collision events. In this framework, we have developed a new hodoscope of silicon detectors for charged particles called OSCAR. This new device consists of individual modules with partially embedded electronics capable to identify low energy particles down to about 1 MeV/u. OSCAR is a particularly suitable detector to be used as a standalone detector or as ancillary system for large acceptance devices. This paper presents an overview of the layout and capabilities of the detector.

The Barrel-Time-of-Flight detector is one of the outer layers in the multi-layer design of the P anda target spectrometer, covering a polar angle region of 22 ° θ l a b 150 ° . P anda , which is being built at the FAIR facility, will use cooled antiprotons on a Hydrogen or nuclei target, to study a variety of topics in hadron physics. The detector is a scintillating tile hodoscope with an SiPM readout. A single unit consists of a 90 × 30 × 5 mm 3 fast plastic scintillator tile and 3 × 3 mm 2 SiPM photosensors on both ends. Four SiPMs are connected in series to overcome the limited sensor size of a single SiPM sensor and to improve the time resolution drastically (100 ps to 50 ps). While the P anda experiment is equipped with DIRC detectors for PID of faster particles, the Barrel TOF complements the setup by providing additional PID information with a π /K separation of 4 sigma up to the Cherenkov threshold.

The time resolution of the prototype counters for a new charged particle hodoscope for the NA62 experiment has been measured. The prototype scintillation counters with dimensions of 90 × 90, 100 × 100, 150 × 150, 180 × 100, and 270 × 100 mm are investigated. Several variants of direct light collection from a scintillator brink and a corner are considered, as well as light collection using wavelength-shifting (WLS) fibers. Silicon photodiodes from the Centre of Perspective Technologies and Apparatuses (CPTA) and SensL, as well as a compact R7400U photomultiplier tube were used as photodetectors. An R7899-20 photomultiplier tube with a high quantum efficiency in the green spectral region is used as a reference counter. The measurements have been taken with cosmic muons and the beam halo of beamline 21 in the zone of the OKA experiment. The time resolution of a 100 × 100 mm cell, averaged over the area, is 590 ± 10 ps in the case of the WLS-fiber readout and 260 ± 25 ps in the case of direct light collection from the scintillator brink.

We developed a field-programmable gate array (FPGA) TDC module for the tracking devices of Fermilab SeaQuest (E906) experiment, including drift chamber, proportional tube and hodoscope. The requirement of time resolution is better than 4 ns. This 64-channel TDC is made of a 6U VMEbus unit equipped with a Microsemi ProASIC3 Flash based FPGA of low power and high radiation tolerance. The new FPGA firmware (Run2-TDC) is designed to reduce the data volume and data acquisition (DAQ) deadtime. The firmware digitizes multiple input hits of both polarities while allowing users to turn on a multiple-hit elimination logic to remove after-pulses in the wire chambers and proportional tubes. A scaler is fitted into the firmware of each channel to allow for recording the number of hits in its respective channel. The TDC resolution is determined by internal cell delays of 450 ps, and a measurement precision of 200 ps has been achieved. As a demonstration of constructing the Wave Union TDC using an existing multi-hit TDC without modifying its firmware, external wave union launchers are utilized in our test to improve the TDC's measurement precision. Measurement precision is nearly halved (108 ps) in data based on a four-edge wave union. An even larger improvement of measurement precision (69 ps) has been reached by combining the approaches of Wave Union TDC and multiple-channel ganging.

Photo-production of hadrons is experimentally studied using 0.8 – 1.2 GeV photon beams at the Research Center for Electron Photon Science, Tohoku University, Japan. Photons areproduced at the bremsstrahlung process by inserting a carbon fiber into the circulating electrons in the 1.3 GeV electron synchrotron. The energy of each photon is determined from the trajectory of the corresponding recoil electron. The energy resolution and time resolution of the current photontagging system is not enough high for the next-generation physics program. We have developed a new system called TaggerIIs. The angular resolution should be higher than 5° to reject the background particles coming from other points than the carbon fiber. The time resolution is required to be less than 200 ps to identify the bunch corresponding to a produced photon. We have adopted a combined system of a multi wire drift chamber and plastic-scintillator hodoscope for the new system. The wire chamber has a frame with length of 1000 mm along pole shape of a bending magnet and consists of 3 sense wire planes (X, X’, X) of wire length of 116 mm. A shape of the cell is hexagonal andthe spacing of the sense wires is 6 mm. The hodoscope consists of 60 plastic scintillators (EJ212) of 30 mm height and 5mm thickness. The width of each scintillator is designed from 5 mm to 30 mm. A performance of the new system has been tested using positron beams. As a result, weachieved that the detection efficiency of the wire chamber was 99%, the angler resolution was 0.60\ensuremath{\unicode{0x25E6 \textbf{and the timing resolution of the hodoscope was 165.8 ps.

The POLAR detector is a space based Gamma Ray Burst (GRB) polarimeter with a wide field of view, which covers almost half the sky. The instrument uses Compton scattering of gamma rays on a plastic scintillator hodoscope to measure the polarization of the incoming photons. The instrument has been successfully launched on board of the Chinese space laboratory Tiangong 2 on September 15, 2016. The construction of the instrument components is described in this article. Details are provided on problems encountered during the construction phase and their solutions. Initial performance of the instrument in orbit is as expected from ground tests and Monte Carlo simulation.

Results of investigating an assembly of thin scintillators and silicon photomultipliers for registering relativistic particles with the minimum ionization are presented. A high efficiency of registering relativistic particles using an Ej-212 plastic scintillator, BSF-91A wavelength-shifting fiber (Saint-Gobain), and a silicon photomultiplier (Hamamtsu) is shown. The measurement results are used for creating a scintillation hodoscope of the magnetic spectrometer for registering γ quanta in the GlueX experiment.

This hodoscope is a position sensitive detector used in physics experiments at accelerators, for determination of position resolution of particles generated in nuclear interactions at high energy (√SNN=3-11GeV). This detector is a new type of device which uses plastic scintillators strips coupled to Hamamatsu PIN photodiodes. Usually in this kind of experiments are used position-sensitive devices on base of silicon strips and/or plastic scintillators coupled to photomultipliers(PMT). The first is very good but raises problems in construction, and the second operates at high voltage, resolution is high and its characteristics are affected by magnetic fields. The biggest advantage of the proposed hodoscope consists in easy construction, his characteristics is not influenced by high magnetic fields and has good performance in position resolution (< 5mm). This performance is obtained using an associated electronics which assures a multiparametric determination. The detector structure is made from two perpendicular planes of plastic scintillator strips, each having eight elements. Every strip is coupled to very small charge sensitive preamplifiers.

We present a multi-channel, fast-neutron/photon detection system that uses ZnS(Ag) scintillator detectors. The system employs field-programmable gate arrays to pulse-shape analysis for real-time all-digital neutron/photon differentiation, producing particle-dependent pulse height and temporal distributions while allowing count rates in excess of 1,000,000 events per second per channel. The system size is scalable in blocks of 16 channels.

A space dark matter detector is proposed by the Key Laboratory of Dark Matter And Space Astronomy of Chinese Academy of Sciences for detecting the high-energy electrons and Gamma particles produced by the annihilation of dark matter in space. The whole detector is mainly composed of the BGO (bismuth germanium oxide) high-energy image calorimeter and scintillation hodoscope. The energy range of the detector will cover the high-energy electrons and Gamma particles of 10 Gev∼10 TeV, in which the energies of high-energy particles are mainly deposited in the BGO calorimeter. For verifying the scheme of the detector, we have designed a prototype readout system for the BGO calorimeter of the space dark matter detector, and made a preliminary test on it.

The Barrel Time-of-Flight detector system will be installed in the upcoming ANDA experiment at FAIR in Germany. The detector has a barrel shape of =0.5 m and 1.8 m long, covering about 5 m2, which corresponds to the laboratory polar angle coverage of 22o

International audience; The MoniDiam project is part of the French national collaboration CLaRyS (Contrôle en Ligne de l'hAdronthérapie par RaYonnements Secondaires) for on-line monitoring of hadron therapy. It relies on the imaging of nuclear reaction products that is related to the ion range. The goal here is to provide large area beam detectors with a high detection efficiency for carbon or proton beams giving time and position measurement at 100 MHz count rates (beam tagging hodoscope). High radiation hardness and intrinsic electronic properties make diamonds reliable and very fast detectors with a good signal to noise ratio. Commercial Chemical Vapor Deposited (CVD) poly-crystalline, heteroepitaxial and monocrystalline diamonds were studied. Their applicability as a particle detector was investigated using α and β radioactive sources, 95 MeV/u carbon ion beams at GANIL and 8.5 keV X-ray photon bunches from ESRF. This facility offers the unique capability of providing a focused (~1 µm) beam in bunches of 100 ps duration, with an almost uniform energy deposition in the irradiated detector volume, therefore mimicking the interaction of single ions. A signal rise time resolution ranging from 20 to 90 ps rms and an energy resolution of 7 to 9% were measured using diamonds with aluminum disk shaped surface metallization. This enabled us to conclude that polycrystalline CVD diamond detectors are good candidates for our beam tagging hodoscope development. Recently, double-side stripped metallized diamonds were tested using the XBIC (X Rays Beam Induced Current) setup of the ID21 beamline at ESRF which permits us to evaluate the capability of diamond to be used as position sensitive detector. The final detector will consist in a mosaic arrangement of double-side stripped diamond sensors read out by a dedicated fast-integrated electronics of several hundreds of channels. Index Terms— Synthetic diamond detectors, on-line monitoring of hadron therapy, charge collection efficiency, time resolution, integrated fast read out electronics

We describe a PET device based on a novel method to extract the coordinates of the interaction point of the 511keV γ rays from 100 mm long and thin LYSO (Lutetium Yttrium OxyorthoSilicate) scintillator bars, positioned axially in the tomograph. The coordinate along the hit crystal is measured by using a hodoscope of Wave Length Shifting (WLS) plastic strips mounted perpendicularly to each plane of scintillators. As photodetectors, new Geiger mode Avalanche PhotoDetectors (G-APDs) with integrated electronics are being used to detect both the hit crystal in a block (x and y coordinates) and the interaction point in the crystal (z coordinate) through the light escaping from the crystal and transmitted to the WLS strips. In this way, the γ interaction point can be determined with a spatial resolution of few cubic millimeters down to a minimum deposited energy of about 50 keV, resulting in a volumetric precision very close to the limits imposed by the physics of the positron annihilation. The method allows to increase the detection efficiency without affecting the spatial resolution by adding scintillator planes in the radial direction. A demonstrator scanner, based on two matrices of 8 × 6 LYS crystals and 312 WLS strips, slotted in between the crystals, is under construction. Preliminary results from the feasibility studies of the various components will be presented.

Firmware for checking the electronic equipment for recording signals of the hodoscope γ-quantum detector is described. The detector has 1344 channels for measuring charges of nanosecond pulses arriving from outputs of photomultiplier tubes. The testing system is intended to test the electronics at each level of its hierarchical structure and also to perform the initial check of the γ-quantum detector itself.

Results of the analysis of the state-of-the-art time-of-flight measurement technique with the use of long scintillation counters with a small cross section (the length of the counter far exceeds its width in the plane of the hodoscope and thickness along the beam direction), which are used as basic elements of time-of-flight detectors for large physical installations and intended for identifying secondary particles generated during collisions of high-energy particles. The following issues are considered in this review. Various methods for identifying particles are compared, and it is pointed out that the time-of-flight method has certain advantages for secondary particles with momenta higher than ∼3–5 GeV/c. Some elements incorporated in scintillation counters and affecting its time resolution are considered: optical fibers, optical contacts in the scintillator-fiber-photodetector system, and high-frequency cables. Their characteristics are presented. The characteristics of all elements of a counter (scintillator, photodetector (PD), and electronics) and the processes occurring in them are discussed. The presented experimental data show that, under the conditions of high counting rates and strong magnetic fields, the working capacity of counters holds at a time resolution of ∼100–200 ps. The results of measuring the operating characteristics of counters are analyzed. The dependences of the time resolution on such variables as the coordinate of the particle transit through a counter along its length, the counter length, the light-absorption length in the scintillator, the quality of treatment of the scintillator’s surface, and the energy deposited by a particle in the scintillator substance are considered. The main characteristics of individual time counters and average parameters of time-of-flight detectors in certain physical facilities are presented. Possible ways to improve the time resolution and reduce it to ∼50–100 ps are considered.

In response to the critical need of more effective bio-dosimetric techniques to improve cancer risk estimation, this paper focuses on the design of an advanced biomedical instrumentation that could be used for radiation risk analysis on space missions. A designed concept for a hodoscope for radiation detection and tracking is tested via Monte Carlo simulation. The device consists of a set of layers of scintillating fibers, above and below a biological sample, in a design that allows for the determination of the direction of incoming and outgoing radiation. The efficiency of energy deposition on each of the different layers of the device is studied for proton radiation. The study of the response for different incoming energy is the main focus, but fiber-size is also a designed parameter considered in this study. The optimum energy range as found to be around 30 MeV’s – 50MeV’s depending on arrangement. It is found that energy deposited by protons in the optimum range in 1 mm-diameter fibers, is large enough for detection. Since smaller fibers allow for larger resolution, it is concluded that they are preferable than 2 mm fibers. Alternative arrangements consisting respectively of 3 and 4 layers of fibers on each side of the sample are tested and compared. It is observed that although one more coordinate for the source is needed, the 3-layers array is a viable alternative when that extra information is available. With this arrangement, the device is sensitive to lower energy photons.

International audience; A Compton camera is being developed for the purpose of ion-range monitoring during hadrontherapy via the detection of prompt-gamma rays. The system consists of a scintillating fiber beam tagging hodoscope, a stack of double sided silicon strip detectors (90 Â 90 Â 2 mm 3 , 2 Â 64 strips) as scatter detectors, as well as bismuth germanate (BGO) scintillation detectors (38 Â 35 Â 30 mm 3 , 100 blocks) as absorbers. The individual components will be described, together with the status of their characterization.

A pair of new hodoscopes made of 0.28 mm O scintillating fibre have been built and tested at T11 beam line of CERN PS. They consist of seven layers of fibres, and are read out using multi-anode photomultipliers. The average number of photoelectrons produced by a minimum ionizing particle is found to be about 11, which resulted in a very high detection efficiency (98.6%) at an appropriate threshold setting. The hit multiplicity for single-hit events was suppressed to 1.12 at this threshold setting, thanks to the Peak-Sensing Circuit used for the readout. A spatial resolution of ∼ 75 μ m and a time resolution of ∼ 0.56 ns (both in RMS) have been obtained with these hodoscopes. Further detailed study of the detector response such as double hit efficiency at very close distances, dependence on the incident angles has been performed.

The DAFNE Beam Test Facility (BTF), operational in Frascati LNF since November 2002, is a beam transfer line optimized for single particle production, mainly for high-energy detectors calibration. It can provide e − / e + beams in a wide range of intensity – between single particle and 1010 particles/pulse – and energy, from few tens of MeV up to 800 MeV; the pulse duration can also be adjusted between 1 and 10 ns at a maximum repetition rate of 50 Hz. In the last year many groups have accessed the facility, for testing a number of apparata: silicon detectors, calorimeters, scintillator counters, GEM (in single particle mode); fluorescence counters, crystal and nanotube bendings, Cerenkov counters, thermo-acoustical detectors (at high intensity). The large beam multiplicity range required to implement different diagnostic devices: calorimeters for particle counting at low intensity, fluorescence chambers and Cerenkov detectors for intermediate-high intensity monitor, up to standard beam diagnostic systems. The beam spot profile and position is also measured by means of a x-y scintillating fiber hodoscope with multi-anode PMT readout.

A scintillating fibre detector with high spatial granularity was built for the Crystal Barrel experiment at ELSA (CB-ELSA) in Bonn. It consists of 513 scintillating fibres with 2 mm in diameter, arranged in three layers with cylindrical geometry inside the Crystal Barrel detector surrounding the target cell. Two layers are wound in opposite directions, the third is parallel to the incident beam direction, resulting in an unambiguous hit reconstruction and a position resolution better than 1.6 mm for charged particles. The read-out is done with 16-channel multi-anode photomultipliers. The detector was designed to cover the full angular acceptance of the Crystal Barrel detector with an angular range of 12 ∘ ⩽ θ ⩽ 168 ∘ and 0 ∘ ⩽ φ ⩽ 360 ∘ in the lab frame.

Timing properties of two types of scintillation counters have been studied in 5 GeV /c hadron beam of the IHEP (Protvino) accelerator. The counters are prototypes of hodoscope elements that will be used in experiments for particle identification and fast timing of events. Scintillator cross-sections are 1.25×6.0 and 2.5×2.5 cm 2 and their length is 2 m . The dependence of the time resolution on the particle coordinate along the counters and on the beam intensity is presented.

The CsI(Tl) Detector Element (CDE) is the unit of detection of the calorimeter subsystem of the Large Area Telescope (LAT) of the GLAST satellite (IEEE Nuclear Science Symposium, 2002), which will be launched in September 2006. The LAT consists of 4×4 identical towers, each one including a strip silicon tracker on the top and a CsI(Tl) calorimeter on the bottom. A segmented plastic scintillator anticoincidence detector surrounds the 16 towers. The calorimeter modules, 8 layers of 12 CDEs each, have a hodoscope's shape to allow the measurement of the gamma-ray direction. The CDE main characteristics are its Light Yield, the energy resolution and the tapering, ratio of left/right signals used for the determination of the crossing position of the particle in the crystal. The CDE have to operate in space at about −10°C. We will describe the CDE, the optimization of its main parameter, the L.Y., and finally its variation with temperature.

We describe the facility for RPC test with cosmic rays, designed and built at the laboratory of INFN and University of Naples. Trigger and tracking systems consist of a scintillator hodoscope and two drift chambers with track reconstruction resolution of similar to400 mum. Trigger is provided by the twofold coincidence of scintillators covering a surface of 1 m(2). Two step motors move chambers synchronously along the station for RPC scanning. Up to eight RPCs can be tested simultaneously. (C) 2003 Elsevier Science B.V. All rights reserved.

A scintillating fibre hodoscope was developed for application in a high rate environment such as the central region of external beam experiments. It accommodates rates of several 10 6 s −1 per fibre channel while maintaining a time resolution of about 400 ps . Its central elements are highly efficient radiation-hard scintillating fibres and a photomultiplier tube capable of operating at such rates without appreciable loss of signal amplitude.