LaBr3:Ce crystals have been introduced for radiation imaging in medical physics, with photomultiplier or single SiPM readout. An R&D was pursued with 1/2″ and 1″ LaBr3:Ce crystals, from different ...producers, to realize compact large area detectors (up to some cm2 area) with SiPM array readout, aiming at high light yields, good energy resolution, good detector linearity and fast time response for low-energy X-rays. A natural application was found inside the FAMU project at RIKEN-RAL muon facility, that aims at a precise measure of the proton Zemach radius to solve the so-called “proton radius puzzle”, triggered by the recent measure of the proton charge radius at PSI. The goal is the detection of characteristic X-rays around 130 keV. Other applications may be foreseen in medical physics, such as PET, and gamma-ray astronomy. A limiting factor is the gain drift of SiPM arrays with temperature, that give a deterioration of the detector’s FWHM energy resolution. To solve this problem, a custom NIM module, based on CAEN A7585 digital power supply, was developed. Test results of the correction of gain drift with temperature for SiPM arrays from Advansid, Sensl, Hamamatsu will be presented. At the 137Cs peak, an energy resolution better than 3% was obtained for a typical LaBr3:Ce crystal, using Hamamatsu S13461 arrays. This compares well with best available results obtained with a PMTs.
Muon beams of high brilliance are basilar for future facilities such as a Neutrino Factor)', an Higgs-factory or a multi-TeV Muon Collider, Along this R&D path, cooling of the incoming muon beams is ...essential: cooling factors up to ~ 10 super(6) are needed in the Muon Collider case. Due to the need for fast cooling (as the muon lifetime is ~ 2.2 mu s) the only practical solution is "ionization cooling", realized via energy loss in a suitable absorber and re-acceleration of muons by r,f, cavities in the longitudinal direction. Ionization cooling is effective only in the transverse directions. For a 6-D cooling, where also a longitudinal cooling is needed, the only viable solution is by "emittance exchange". The fundamental R&D on cooling is the subject of this review,
The FAMU experiment aims to measure for the first time the hyperfine splitting of the muonic hydrogen ground state. From this measurement the proton Zemach radius can be derived and this will shed ...light on the determination of the proton charge radius. In this paper, we describe the scientific goal, the method and the detailed preparatory work. This includes the outcome of preliminary measurements, subsequent refined simulations and the evaluation of the expected results. The experimental setup being built for the measurement of the hyperfine splitting to be performed at the RAL laboratory muon facility is also described.
The ICARUS-T600 Liquid Argon (LAr) Time Projection Chamber (TPC) is taking data with the Fermilab Booster Neutrino Beam-line (BNB) in the Short Baseline Neutrino (SBN) program to search for a ...possible LSND-like sterile neutrino signal. A light detection system, based on 360 Hamamatsu R5912-MOD Photo-Multiplier Tubes (PMTs) deployed behind the TPC wire chambers, has been realized to detect vacuum ultraviolet (VUV) photons produced by ionizing particles in LAr. This system is fundamental for the detector operation, providing an efficient trigger and contributing to the 3D reconstruction of events. Moreover, since the TPC is exposed to a huge flux of cosmic rays due to its shallow depths operations, the light detection system allows for the time reconstruction of events, contributing to the identification and to the selection of neutrino interactions within the beam spill gates.
Abstract
The ICARUS-T600 Liquid Argon (LAr) Time Projection Chamber (TPC) is presently taking data
in the Short Baseline Neutrino (SBN) program at Fermilab (U.S.A.) to search for a possible LSND-like
...sterile neutrino signal at Δ
m
2
≈ 1 eV
2
with the Booster Neutrino Beam (BNB). A
light detection system, based on 360 large area Photo-Multiplier Tubes (PMTs), has been realized
for ICARUS-T600 to detect VUV photons produced by the passage of ionizing particles in LAr. This
system is fundamental for the TPC operation, providing an efficient trigger and contributing to
the 3D reconstruction of events. Moreover, since the detector is exposed to a huge flux of cosmic
rays due to its shallow depths installation, the light detection system allows for the time
reconstruction of events, contributing to the identification and to the selection of genuine
neutrino interactions. The correct time reconstruction of events requires the precise knowledge of
the delay of each PMT channel and a good synchronization of recording electronics, this last based
on fast sampling digitizers. To achieve a time resolution better than 1 ns, we perform three
consecutive timing corrections deployed at different stages of the optical data flow. Results
demonstrate the capability of the ICARUS-T600 light detection system to allow a precise
reconstruction of the temporal evolution of each event occurring in the detector and the
association of neutrino events with the bunched structure of BNB.
The idea of the CHNET-TANDEM experiment is to develop and optimize a non-destructive technique, which allows analysis deep inside the sample with a good spatial resolution, using a negative muon ...beam. By selecting the primary muon energies appropriately, bulk analysis can be performed without destructing the sample. The experimental setup used for this experiment, made by 2 hodoscopes and 5 HpGe, allowed us to collect very interesting preliminary data concerning scan momentum, positioning and centering of the samples by means of two hodoscopes, analysis of standard material targets and elemental characterization of Nuragic “Bronze Age” votive ship fragments.
Abstract
The FAMU experiment aims at an indirect measurement of the Zemach radius of the
proton. The measurement is carried out on muonic hydrogen atoms (μH) produced through the
low-momentum (50–60 ...MeV/c) muon beam a the RIKEN-RAL μ
-
facility. The particle flux plays
an important role in this measurement, as it is proportional to the number of μH atoms
produced, which is the target of the FAMU experimental method. The beam monitor calibration
technique and results, presented here, are meant to extract a reliable estimation of the muon flux
during the FAMU data taking. These measurements were carried out at the CNAO synchrotron in Pavia,
Italy, using proton beams and supported by Monte Carlo simulation of the detector in Geant4.
ICARUS T600 is the far detector of the Short Baseline Neutrino program at Fermilab (U.S.A.), which foresees three Liquid Argon Time Projection Chambers along the Booster Neutrino Beam line to search ...for LSND-like sterile neutrino signal. The T600 detector underwent a significant overhauling process at CERN, introducing new technological developments while maintaining the already achieved performances. The realization of a new liquid argon scintillation light detection system is a primary task of the detector overhaul. As the detector will be subject to a huge flux of cosmic rays, the light detection system should allow the 3D reconstruction of events contributing to the identification of neutrino interactions in the beam spill gate. The design and implementation of the new scintillation light detection system of ICARUS T600 is described.
The ICARUS T600 LAr TPC is the far detector of the Short Baseline Program at FNAL. As it will have to work at shallow depth in the Booster Neutrino Beam, a large cosmic rays background (∼11 kHz) will ...be present. To reduce it, precise timing information is needed from the new light detection system, based on 360 large area photomultipliers. For precise time measurements a calibration system based on a fast laser diode and a system based on one optical switch, several 01×1 fused fiber splitters, ultra-high vacuum optical feedthroughs and multimode optical patchcords up to 20 m long, to distribute the laser pulses to each single PMT, was designed. The time evolution of the PMTs' gain/timing and possibly their initial calibrations at a time t0 will be done by using this system. The expected time resolution of this calibration system will be around 100 ps. The laboratory tests needed to set up the system are reported.
The high precision measurement of the hyperfine splitting of the muonic-hydrogen atom ground state with pulsed and intense muon beam requires careful technological choices both in the construction of ...a gas target and of the detectors. In June 2014, the pressurized gas target of the FAMU experiment was exposed to the low energy pulsed muon beam at the RIKEN RAL muon facility. The objectives of the test were the characterization of the target, the hodoscope and the X-ray detectors. The apparatus consisted of a beam hodoscope and X-rays detectors made with high purity Germanium and Lanthanum Bromide crystals. In this paper the experimental setup is described and the results of the detector characterization are presented.
PDF
