Search results for "Icon"
showing 10 items of 3539 documents
2.45 GHz synchronised polarised electron injection at MAMI
1998
Abstract A semiconductor modelocked diode laser has been used to produce picosecond spin-polarised electron bunches from strained GaAsP photocathodes and inject them into MAMI, synchronised to the 2.45 GHz accelerating field. The laser meets the operational requirements of MAMI producing stable electron beams, with a polarisation purity of 72% and a transmission efficiency of 52% at an accelerated beam current of 10.1 μA.
Time of flight measurements based on FPGA and SiPMs for PET–MR
2014
Coincidence time measurements with SiPMs have shown to be suitable for PET/MR systems. The present study is based on 3 x 3 mm(2) SiPMs, LSO crystals and a conditioning signal electronic circuit. A Constant Fraction Discriminator (CFD) is used to digitalize the signals and a TDC FPGA-implemented is employed for fine time measurements. TDC capability allows processing the arrival of multiple events simultaneously, measuring times under 100 ps. The complete set-up for time measurements results on a resolution of 892 +/- 41 ps for a pair of detectors. The details of such implementation are exposed and the trade-offs of each configuration are discussed. (C) 2013 Elsevier By, All rights reserved,
Detector blockbased on arrays of 144 SiPMs and monolithic scintillators: A performane study
2015
[EN] We have developed a detector block composed by a monolithic LYSO scintillator coupled to a custom made 12 12 SiPMs array. The design is mainly focused to applications such as Positron Emission Tomography. The readout electronics is based on 3 identical and scalable Application Specific Integrated Circuits (ASIC). We have determined the main performance of the detector block namely spatial, energy, and time resolution but also the system capability to determine the photon depth of interaction, for different crystal surface treatments. Intrinsic detector spatial resolution values as good as 1.7 mm FWHM and energies of 15% for black painted crystals were measured. & 2014 Elsevier B.V. All…
Development of silicon pad detectors and readout electronics for a Compton camera
2003
Abstract Applications in nuclear medicine and bio-medical engineering may profit using a Compton camera for imaging distributions of radio-isotope labelled tracers in organs and tissues. These applications require detection of photons using thick position-sensitive silicon sensors with the highest possible energy and good spatial resolution. In this paper, research and development on silicon pad sensors and associated readout electronics for a Compton camera are presented. First results with low-noise, self-triggering VATAGP ASIC's are reported. The measured energy resolution was 1.1 keV FWHM at room temperature for the 241 Am photo-peak at 59.5 keV .
A prototype of very high resolution small animal PET scanner using silicon pad detectors
2007
Abstract A very high-resolution small animal positron emission tomograph (PET), which can achieve sub-millimeter spatial resolution, is being developed using silicon pad detectors. The prototype PET for a single slice instrument consists of two 1 mm thick silicon pad detectors, each containing a 32×16 array of 1.4×1.4 mm pads readout with four VATAGP3 chips which have 128 channels low-noise self-triggering ASIC in each chip, coincidence units, a source turntable and tungsten slice collimator. The silicon detectors were located edgewise on opposite sides of a 4 cm field-of-view to maximize efficiency. Energy resolution is dominated by electronic noise, which is 0.98% (1.38 keV) FWHM at 140.5…
In-beam spectroscopy with intense ion beams: Evidence for a rotational structure in246Fm
2012
The rotational structure of ${}^{246}$Fm has been investigated using in-beam $\ensuremath{\gamma}$-ray spectroscopic techniques. The experiment was performed using the JUROGAMII germanium detector array coupled to the gas-filled recoil ion transport unit (RITU) and the gamma recoil electron alpha tagging (GREAT) focal plane detection system. Nuclei of ${}^{246}$Fm were produced using a 186 MeV beam of ${}^{40}$Ar impinging on a ${}^{208}$Pb target. The JUROGAMII array was fully instrumented with Tracking Numerical Treatment 2 Dubna (TNT2D) digital acquisition cards. The use of digital electronics and a rotating target allowed for unprecedented beam intensities of up to 71 particle-nanoamper…
First measurement of the lifetime of the charmed strange baryon Ξc0
1990
Abstract We have observed four unambiguous decays of the charmed strange baryon Ξco in the NA32 experiment at CERN. Charge- coupled devices and silicon microstrip detectors were used to reconstruct the decay mode Ξ c o → pK − K ∗ (892) o seen in events produced by the interaction of 230 GeV/c negative poins and kaons on a copper target. We present the first measurement of the lifetime of the Ξco, together with a determination of its mass and production cross section. The resonant components of the Ξco decay are studied. We use our earlier measurement of the mass of the Ξc+ in the determination of the isospin mass splitting of the Ξc states.
Spectroscopy of Transfermium Nuclei
2006
The advent of efficient recoil separator devices coupled to large arrays of germanium detectors and versatile focal plane detection systems has in recent years allowed a wealth of spectroscopic information to be obtained for transfermium nuclei. At the Department of Physics at the University of Jyvaskyla, the RITU gas‐filled separator is employed in conjunction with the GREAT focal plane spectrometer and the JUROGAM array of germanium detectors. Whilst initial studies using these devices concentrated on even‐even nuclei, more recent experiments have attempted to study single‐particle properties by examining the structure of odd‐mass nuclei and multi‐quasiparticle states. An overview of the …
Electron Scattering Experiments at the Mainz 300 MeV Linear Accelerator
1970
The Mainz electron scattering facility provides energies between 80 and 300 MeV and scattering angles up to 158° which corres-pond to a useful momentum transfer region 0.4 ≤ q ≤ 3.0 fm−1. The accelerator and analyzing system produce approximately 1 μA average current with the overall resolution in the final spectra of usually 0.15% to 0.30%.
Photonuclear reactions induced by a clinical linac
2015
1st NUBA International Conference on Nuclear Physics and Astrophysics -- SEP 14-21, 2014 -- Akdeniz Univ, Antalya, TURKEY