The main goal of the FAMU experiment is the measurement of the hyperfine splitting (hfs) in the 1S state of muonic hydrogen ΔEhfs (μ - p)1S. The physical process behind this experiment is the ...following: μp are formed in a mixture of hydrogen and a higher-Z gas. When absorbing a photon at resonance-energy ΔEhfs ≈ 0.182 eV, in subsequent collisions with the surrounding H 2 molecules, the μp is quickly de-excited and accelerated by ∼ 2/3 of the excitation energy. The observable is the time distribution of the K-lines X-rays emitted from the μZ formed by muon transfer (μp) + Z → (μZ)* + p, a reaction whose rate depends on the μp kinetic energy. The maximal response, to the tuned laser wavelength, of the time distribution of X-ray from K-lines of the (μZ)* cascade indicate the resonance. During the preparatory phase of the FAMU experiment, several measurements have been performed both to validate the methodology and to prepare the best configuration of target and detectors for the spectroscopic measurement. We present here the crucial study of the energy dependence of the transfer rate from muonic hydrogen to oxygen (Λ μp → μ0 ), precisely measured for the first time.
The FAMU experiment aims to accurately measure the hyperfine splitting of the ground state of the muonic hydrogen atom. A measurement of the transfer rate of muons from hydrogen to heavier gases is ...necessary for this purpose. In June 2014, within a preliminary experiment, a pressurized gas-target was exposed to the pulsed low-energy muon beam at the RIKEN RAL muon facility (Rutherford Appleton Laboratory, U.K.). The main goal of the test was the characterization of both the noise induced by the pulsed beam and the X-ray detectors. The apparatus, to some extent rudimental, has served admirably to this task. Technical results have been published that prove the validity of the choices made and pave the way for the next steps. This paper presents the results of physical relevance of measurements of the muon transfer rate to carbon dioxide, oxygen, and argon from non-thermalized excited μp atoms. The analysis methodology and the approach to the systematics errors are useful for the subsequent study of the transfer rate as function of the kinetic energy of the μp currently under way.
FLARES (a Flexible scintillation Light Apparatus for Rare Event Searches) is a project for an innovative detector technology to be applied to rare event searches, and in particular to neutrinoless ...double beta decay experiments. Its novelty is the enhancement and optimization of the collection of the scintillation light emitted by ultra-pure crystals through the use of arrays of high performance silicon photodetectors cooled to 120 K. This would provide scintillation detectors with ~1% level energy resolution, with the advantages of a technology offering relatively simple low cost mass scalability and powerful background reduction handles, as requested by future neutrinoless double beta decay experimental programs.
Silicon Photomultipliers (SiPM) are considered very promising in many application where high timing performances, low cost, hardness to radiation damage and single photon counting are requested. Such ...applications go from astrophysics, high energy accelerator physics to medical physics. A group of SiPM from Hamamatsu has been tested with a low noise fast amplifier based on a hetero-junction FET, mounted on a proper front end board. A first telescope prototype has been used to test the electronics and results are shown. The SiPM time resolution has been measured to be σ∼30ps, in agreement with other studies reported in literature. The SiPM gain depends critically on temperature and a thermoelectric module to control the circuit was also studied in order to use the system for space detectors.
Low-noise, position-sensitive Silicon Drift Detectors (SDDs) are particularly useful for experiments in which a good energy resolution combined with a large sensitive area is required, as in the case ...of X-ray astronomy space missions and medical applications. This paper presents the experimental characterization of VEGA, a custom Application Specific Integrated Circuit (ASIC) used as the front-end electronics for XDXL-2, a large-area (30.5 cm super(2)) SDD prototype. The ASICs were integrated on a specifically developed PCB hosting also the detector. Results on the ASIC noise performances, both stand-alone and bonded to the large area SDD, are presented and discussed.
Study of silicon photomultipliers fast amplifier and thermoregulation D’antone, I.; Fabbri, L.; Foschi, E. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2011, Letnik:
630, Številka:
1
Journal Article
Recenzirano
The silicon photomultipliers (SiPM) are adopted in various physical applications, from medical physics to astrophysics, for their advantages in terms of cost and weight with respect to traditional ...photo detectors. Their low bias voltage supply (about 30
V), hardiness and resistance to magnetic field are ideal characteristics for space application. In the frame of INFN-Irst collaboration, some of them have been developed and produced at FBK (Trento-Italy), and have been characterized in the INFN laboratories of Bologna (DaSiPM2 collaboration).
The SiPM can be used in conjunction with fibres and counters in high energy physics experiments. To exploit the SiPM time resolution, a fast amplifier has been studied. The SiPM gain depends critically on temperature and a thermal stabilization is also necessary. The use of a thermoelectric cooler module based on a Peltier cell has been investigated, and the results are shown.
The ALICE Time-of-Flight system will be a large area (150m2) detector made by Multigap RPC (MRPC). The time digitisation is based on the High Performance TDC chip (HPTDC). Tests carried out on board ...prototypes are discussed, emphasising the optimisation of the effective time resolution of the chip when working in its Very High Resolution Mode. Lab bench tests and test beam results show that a 20ps resolution has been achieved.
An Application Specific Integrated Circuit (ASIC) designed as front-end electronics for large area monolithic Silicon Drift Detectors (SDD) read-out has been developed and tested. The challenging ...framework of this project is the read-out of the large-area SDD detectors to be used for X-ray astronomy space missions and medical applications. Due to the inherent low noise of the SDD, these detectors are able to find application in payloads where instruments capable of good energy resolution combined with position resolution and large area are needed. The ASIC has been tested with a SDD prototype having a sensitive area of 4.35×7.02 cm 2 . The SDD was designed to test both the spectroscopic and imaging performance with different anode pitches (967 μm and 147 μm, respectively) being able to fulfill stringent constraints on low-noise (<; 19 erms and <; 15 er.m.s., respectively) and low-power (<; 0.65 mW/ch). The ASIC prototypes were integrated on specially developed high technology PCB hosting also the SDD. Results of the tests on the ASIC, both stand alone and when connected to the detector, are presented in this work.
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