Behaviour in Magnetic Fields of Fast Conventional and Fine-Mesh Photomultipliers

The performance of both conventional and fine-mesh Hamamatsu photomultipliers has been measured inside moderate magnetic fields. This has allowed the test of effective shielding solutions for photomultipliers, to be used in time-of-flight detectors based on scintillation counters. Both signal amplitude reduction or deterioration of the timing properties inside magnetic fields have been investigated

R&D efforts towards a neutrino factory

The R&D efforts towards a neutrino factory are outlined with special emphasis on the muon cooling issue and the data collected for target optimization.Comment: contribution to NOW08, Conca Specchiulla, Otranto, 200

The design and commissioning of the MICE upstream time-of-flight system

In the MICE experiment at RAL the upstream time-of-flight detectors are used for particle identification in the incoming muon beam, for the experiment trigger and for a precise timing (sigma_t ~ 50 ps) with respect to the accelerating RF cavities working at 201 MHz. The construction of the upstream section of the MICE time-of-flight system and the tests done to characterize its individual components are shown. Detector timing resolutions ~50-60 ps were achieved. Test beam performance and preliminary results obtained with beam at RAL are reported.Comment: accepted on Nuclear Instruments and Methods

A laser diode based system for calibration of fast time-of-flight detectors

A system based on commercially available items, such as a laser diode, emitting in the visible range $\sim 400$ nm,and multimode fiber patches, fused fiber splitters and optical switches may be assembled,for time calibration of multi-channels time-of-flight (TOF) detectors with photomultipliers' (PMTs') readout. As available laser diode sources have unfortunately limited peak power, the main experimental problem is the tight light power budget of such a system. In addition, while the technology for fused fiber splitters is common in the Telecom wavelength range ($\lambda \sim 850, 1300-1500$ nm), it is not easily available in the visible one. Therefore, extensive laboratory tests had to be done on purpose, to qualify the used optical components, and a full scale timing calibration prototype was built. Obtained results show that with such a system, a calibration resolution ($\sigma$) in the range 20-30 ps may be within reach. Therefore, fast multi-channels TOF detectors, with timing resolutions in the range 50-100 ps, may be easily calibrated in time. Results on tested optical components may be of interest also for time calibration of different light detection systems based on PMTs, as the ones used for detection of the vacuum ultraviolet scintillation light emitted by ionizing particles in large LAr TPCs.Comment: submitted to JINS

Deuteron production in p-Be interactions at 450 GeV/c and the coalescing model

The analysis of the deuteron production in p--Be interactions at 450 GeV/c taken by the NA56/SPY experiment at CERN SPS is presented. In the framework of the coalescence model, the coalescence factor $\kappa$ is determined as $(0.79 \pm 0.05 \pm 0.13) \times 10^{-2}$. Our results disfavour the hypothesis that coalescence be the dominant mechanism for deuteron production in $p+Be$ interactions at low $p_T$.Comment: EPS Conference HEP 2007, Mancheste

The FAMU experiment at RIKEN RAL for a precise measure of the proton radius

The goal of the FAMU experiment at RIKEN RAL is the measure of the hyperfine splitting of the ground state of the muonic hydrogen, to allow a determination of the proton Zemach radius with a precision better than $5 \times 10^{-3}$ . The comparison of this measurement with the ones done with ordinary hydrogen may help to solve the so-called "proton radius puzzle", triggered by the $6 \sigma$ discrepancy in the proton charge radius value as extracted from muonic Lamb shift and the value based on e-p scattering and ordinary hydrogen spectroscopy.Comment: European Physical Society Conference on High Energy Physics - EPS-HEP2019 -10-17 July, 2019 Ghent, Belgiu