Fiber Hodoscope Research Articles

A Scintillating Fiber Hodoscope for the SPASCHARM Experiment at the U-70 Accelerator Complex

A Scintillating Fiber Hodoscope for the SPASCHARM Experiment at the U-70 Accelerator Complex

A fast profile monitor with scintillating fiber hodoscopes for high-intensity photon beams

A fast beam-profile monitor has been developed for high-energy photon beamlines at the Research Center for Electron Photon Science, Tohoku University. The position of the photon converted into an electron–positron pair in a 0.5mm-thick aluminum plate is measured with two hodoscopes made of scintillating fibers with cross-sections of 3×3mm2. Events in which charged particles are produced upstream are rejected with a charge veto plastic scintillator placed in front of the plate, and pair-production events are identified with a trigger plastic scintillator placed behind the plate. The position is determined by a developed logic module with a field-programmable gate array. The dead time for processing an event is 35ns, and a high data acquisition efficiency (~100%) can be achieved with this monitor for high-intensity photon beams corresponding to 20MHz tagging signals.

Charged Particle Detection with NUV-Sensitive SiPM in a Beam of Relativistic Ions

Particle detector prototypes equipped with Silicon Photomultipliers designed to be sensitive in the near-ultraviolet wavelength region (NUV-SiPM) were tested in a beam of relativistic ions with electric charge Z in the range 1 ≤ Z ≤ 28, at energies 13 and 30 GeV/amu at CERN SPS. Two different prototypes of charged particle detectors were tested. The first one was a scintillating fiber hodoscope with individual fibers optically coupled to single SiPM devices. The second one consisted of an array of discrete SiPM sensors that were directly exposed to the ion beam to study their capability to trigger an avalanche in response to the ionization generated inside the silicon device. In this paper, we first report the results of the characterization and dedicated tests of the NUV-SiPM sensors that were carried out in our laboratory under controlled conditions; then, we discuss the analysis of the beam test data and the performance of both prototypes.

The Cosmic Ray Energetics And Mass (CREAM) instrument

The Cosmic Ray Energetics And Mass (CREAM) experiment is designed to investigate high-energy (10 12∼10 15 eV) cosmic rays over the elemental range from hydrogen to iron (1⩽ Z⩽26), through a series of long balloon flights. Originally planned to be flown on the first of the new Ultra Long Duration Balloons (ULDB) being developed by NASA, the CREAM instrument was launched as a Long Duration Balloon (LDB) payload from McMurdo Station, Antarctica on December 16, 2004 and flew for a record-breaking 42 days. A second CREAM flight one year later lasted 28 days. The CREAM design is unique in that it obtains two independent energy measurements using a tungsten/scintillator sampling calorimeter and a Transition Radiation Detector (TRD) with up to four independent charge measurements of incident particles using a novel Timing-based scintillator Charge Detector (TCD), a plastic Cherenkov Detector (CD), scintillating fiber hodoscopes, and a Silicon Charge Detector (SCD). The energy limits are determined by trigger efficiency and telemetry bandwidth at the low end and by statistics at the high end.

Diagnostics and Upgrade of the DAFNE Beam Test Facility (BTF)

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.

Construction and test of a scintillator hodoscope for the CREAM experiment

CREAM (Cosmic Ray Energetics And Mass) is a balloon-borne experiment being prepared for the first flight which is scheduled for the end of 2004 from Antarctica. It is designed to perform direct measurements of cosmic ray composition over the elemental range from proton to iron to the supernova energy scale of 10 15 eV in a series of balloon flights using the new Ultra Long Duration Balloon (ULDB) capability under development by NASA. The instrument includes a sampling tungsten/scintillating fiber calorimeter preceded by a graphite target with scintillating fiber hodoscopes, a pixelated silicon charge detector, a transition radiation detector and a segmented timing-based particle-charge detector. The hodoscope system provides track reconstruction capability by means of 4 orthogonal layers of fibers (S0,S1) on top of the carbon target and 2 additional layers (S2) located in between the upper and lower target sections. Its construction technique and beam test results are presented.

Construction and test of a tungsten/Sci-Fi imaging calorimeter for the CREAM experiment

Cosmic Ray Energetics And Mass (CREAM) is a balloon-borne experiment designed to perform direct measurements of cosmic ray composition over the elemental range from proton to iron to the supernova energy scale of 10 15 eV in a series of balloon flights using the new Ultra Long Duration Balloon (ULDB) capability under development by NASA. The first flight of CREAM will take place at the end of 2004 from Antarctica. The instrument includes a sampling tungsten/scintillating fiber calorimeter preceded by a graphite target with scintillating fiber hodoscopes, a pixelated silicon charge detector, a transition radiation detector and a segmented timing-based particle-charge detector. The thin ionization calorimeter has been designed to operate in the range of energies from a few hundred GeV to 1 PeV providing imaging capability in the reconstruction of the showers originating from the interaction of primary nuclei in the carbon target. A twin calorimeter for the second CREAM payload has been built and tested at CERN. Its construction technique and preliminary test results are presented.

A scintillating fibre hodoscope for high rate applications

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.

Time resolution of multi-cladding scintillating fiber hodoscope

Abstract A prototype of a scintillating fiber hodoscope was constructed with multi-cladding scintillating fibers and a multi anode photomultiplier (H6568, HAMAMTSU). The hodoscope has a seven structure of a scintillating fiber with 0.5 mm in diameter and stacked in closest packing in order to improve its efficiency and time resolution. The hodoscope has been tested using a proton beam. The time resolution of about 700 ps in FWHM has been obtained.

A detector system for proton radiography on the gantry of the Paul-Scherrer-Institute

Abstract A detector system for fast in vivo proton radiography on the proton gantry of the Paul Scherrer Institute was developed. The system, consisting of two scintillating fiber hodoscopes and a range telescope made of plastic scintillator tiles, is capable of detecting position and range of 10 6 protons/s as single coincidence events. The spatial resolution achieved for the residual-range images is ≈1 mm and the density resolution is 0.3% for 200 protons/mm2.

A helical scintillating fiber hodoscope

A novel scintillating fiber hodoscope in helically cylindric geometry has been developed for detection of low multiplicity events of fast protons and other light charged particles in the internal target experiment EDDA at the Cooler Synchrotron COSY. The hodoscope consists of 640 scintillating fibers (2.5 mm diameter), arranged in four layers surrounding the COSY beam pipe. The fibers are helically wound in opposing directions and read out individually using 16-channel photomultipliers connected to a modified commercial encoding system. The detector covers an angular range of 9°⩽ Θ ⩽72° and 0°⩽ ϕ ⩽360° in the lab frame. The detector length is 590 mm, the inner diameter 161 mm. Geometry and granularity of the hodoscope afford a position resolution of about 1.3 mm. The detector design took into consideration a maximum of reliability and a minimum of maintenance. An LED array may be used for monitoring purposes.

Scintillating fiber hodoscopes for DIRAC and COMPASS experiments

Fast and precise scintillating fiber detectors using KURARAY fibers and HAMAMATSU multianode H6568 tubes were constructed for new experiments (DIRAC and COMPASS) at CERN. Tests of the DIRAC detector and COMPASS prototype show high detection efficiency, good time and space resolution.

The high-intensity hyperon beam at CERN

A high-intensity hyperon beam was constructed at CERN to deliver Σ − to experiment WA89 at the Omega facility and operated from 1989 to 1994. The setup allowed rapid changeover between hyperon and conventional hadron beam configurations. The beam provided a Σ − flux of 1.4×10 5 per burst at mean momenta between 330 and 345 GeV/ c produced by about 3×10 10 protons of 450 GeV/ c. At the experiment target the beam had a Σ −/π − ratio close to 0.4 and a size of 1.6×3.7cm 2. The beam particle trajectories and their momenta were measured with a scintillating fibre hodoscope in the beam channel and a silicon microstrip detector at the exit of the channel. A fast transition radiation detector was used to identify the pion component of the beam.

Readout of scintillating fibers by avalanche photodiodes operated in the normal avalanche mode

We have evaluated the performance of avalanche photodiodes (APDs) as the photon detectors for scintillating fibers. The signal-to-noise ratios were estimated and experimentally measured with commercially available APDs coupled to 3HF scintillating fibers. Following those basic studies, we have built a prototype of a scintillating fiber hodoscope read out by the APDs. The performance of this prototype is also described. Throughout this work, we considered only the APDs operated in the normal avalanche mode avoiding the problematic Geiger mode operation. In the measurements, APDs were operated at room temperature without using any cooling system.

Scintillating fiber hodoscope for a bremsstrahlung luminosity monitor at an electron–positron collider

The performance of a scintillating fiber (2 mm diameter) position sensitive detector (4.8×4.8 cm2 active area) for the single bremsstrahlung luminosity monitor at the VEPP-2M electron-positron collider in Novosibirsk, Russia is described. Custom electronics is triggered by coincident hits in the Y and Y planes of 24 fibers each, and reduces 64 photomultiplier signals to a 10-bit (X,Y) address. Hits are accumulated (10 kHz) in memory and display (few Hz) the VEPP-2M collision vertex. Fitting the strongly peaked distribution (∼3–4 mm at 1.6 m from the collision vertex of VEPP-2M) to the expected QED angular distribution yields a background in agreement with an independent determination of the VEPP-2M luminosity.

A detector system for hyperon production at the COSY time-of-flight spectrometer

In an experiment at the external COSY beam associated strangeness production will be investigated [1] by measuring total and differential cross sections as well as the polarization of the produced hyperons by means of an almost 4π time-of-flight spectrometer. In a first step we will concentrate on the reaction pp → KΛp. The apparatus will consist of an inner arrangement as start detector and highly granulated scintillator hodoscopes as stop detector. Both parts give information on multiplicity and allow to identify the interesting reaction by means of the delayed charged decay of the Λ. Moreover the tracks of all prompt and delayed reaction products can be reconstructed with high precision. The detector allows the momentum measurement by time-of-flight. To get all this information the inner detector is composed of tiny granulated plastic scintillator detectors, silicon microstrip devices and a scintillating fibre hodoscope. The outer detector barrel with a diameter of about 3m and a length of about 7.5m will consist of three layers of plastic scintillator slabs, two of them bended in helix form. The status of the experiment will be presented. Moreover the results of test measurements for the different detector components will be discussed together with Monte Carlo calculations.

Level 1 tracking trigger and pattern recognition at LHC with a scintillating fibre hodoscope

A scintillating fibre hodoscope aimed at providing a first-level tracking trigger and at enhancing the track pattern recognition capability at LHC is described. The hodoscope performances are discussed on the basis of Monte Carlo simulations. The results show that the performances required at the trigger level in momentum resolution, as well as in fake track rejection, can be achieved at LHC with 24 000 channels, and that the tracking trigger can be implemented at level 1.

A Bevalac calibration of a scintillating optical fiber hodoscope

As part of instrument definition activities for the Advanced Composition Explorer (ACE) we have evaluated a hodoscope comprised of scintillating fibers for possible use in the Cosmic Ray Isotope Spectrometer (CRIS). The hodoscope would determine the trajectories of individual cosmic ray nuclei with 3 ⩽ Z ⩽ 40 and energies up to several hundred MeV/n which stop in four silicon solid state telescopes. We report on the analysis of data from a December 1990 Bevalac calibration of a CRIS test model in which the hodoscope consisted of 200 μm, square cross section, scintillating fibers, and which used silicon detectors for d E/d x - E Tot measurements. The positional resolution obtained with the fiber hodoscope was ∼ 60 μmfor iron nuclei at angles from 0–30° with respect to the normal to the fiber planes. The detection efficiency for iron and silicon nuclei was determined to be > 99% for beam angles of ⩾ 20°.

A scintillating fibre hodoscope with avalanche photodiode readout

We have built a scintillating fibre hodoscope with rectangular fibres of 1.0×0.5 mm2 cross section coupled to avalanche photodiodes operated in the “Geiger” mode. A total of 64 fibres have been arranged in 4 layers to investigate resolution and to obtain high efficiency and negligible cross talk for a special set of fibers. In this paper we describe the advantages and problems associated with such a readout and present results from a test run.

A Fine Grained Scintillating Optical Fiber Hodoscope for Use at ISABELLE

In order to exploit the high event rates at ISABELLE, it will be necessary to have fast detection with fine spatial resolution. The authors are currently constructing a prototype fine-grained hodoscope, the elements of which are scintillating optical fibers. The fibers have been drawn from commercially available plastic scintillator which has been clad with a thin layer of silicone. So far it has been demonstrated with one mm diameter fibers, that with a photodetector at each end, the fibers are more than 99% efficient for lengths of about 60 cm. The readout will be accomplished either with small diameter photomultiplier tubes or avalanche photodiodes used either in the linear or Geiger mode. The program of fiber development and evaluation will be described. In addition an account of the progress on the prototype hodoscope will be given.