No abstract available

No abstract available

[en] MOSFET dosimeters have been exposed to a large range of radiation fields: 192 MeV positive pions, 500 MeV electrons, 23 GeV protons and a wide energy-spectrum of neutrons. This is the first time that pion dosimetry with MOSFETs is presented. The response curves of the devices are given, together with an evaluation of their dynamic range, showing that these dosimeters can be successfully used to monitor radiation fields up to very high doses and fluences. In the 500 MeV electron beam, an irradiation of p⁺/n/n⁺ diodes together with MOSFETs was also performed. The results of this irradiation show that both types of dosimeters can be used in CMS to monitor in real time the radiation environment

[en] In the UK cancer is the leading cause of mortality in people under the age of 75 and accounts for one in four deaths overall. Cancer is currently the third largest NHS (National Health Service) disease programme. Radiotherapy is one of the main forms of cancer treatment, with an overall cure rate of 40 %. In this paper we review the different types of radiotherapy treatments used and we summarise their current status. Particular emphasis will be placed on a new approach to radiotherapy: the multi-modality approach. We will explain how to develop this multi-modality approach and what will be the benefits to the patients. We will discuss the technological challenges faced in the development of such a multi-modality approach to radiotherapy and the advances needed in the fields of dosimetry and quantitative imaging. We will present two examples of R and D projects for future technologies: in-vivo dosimetry and TOF PET imaging.

[en] A tracking detector made of scintillating fibers is being developed at FNAL, for the experiment E835. The tracker will be used for the measurement of the polar angle θ, i.e. of the coordinate along the beam. The small amount of light from the fibers will be detected by solid state devices (Visible Light Photon Counters) with very high quantum efficiency. This paper reports the performance of a fiber tracker prototype, as measured at FNAL. The authors present results on light yield/mip, efficiency and homogeneity of response. They measured an average number of about 14 photoelectrons per mip and an efficiency higher than 99%

[en] In recent years the silicon photomultiplier has been investigated as an alternative to the traditional photomultiplier tube in a range of applications, including Time-of-flight Positron Emission Tomography (TOF-PET). In this paper we discuss a GEANT4 simulation framework, which has been developed to drive the design of a scalable TOF-PET apparatus to be built at the Rutherford Appleton Laboratory, UK. First results presented in this paper simulate the response of an Hamamatsu Multi-Pixel Photon Counter (S10362-33-050c) coupled to LYSO scintillating crystals, with focus on the timing response of coincidence signals

[en] The recently developed Silicon Photo Multiplier (SiPM) is a solid state photon detector operating in the Geiger mode. Due to the avalanche nature of its operation, it has a fast response time, potentially useful in Time-Of-Flight (TOF) applications. This work is aimed at the application of TOF to Positron Emission Tomography (PET). We have characterised SiPMs from two manufacturers in terms of breakdown voltages, dark count rates and the rise times of the signal in response to pulsed light sources. SiPM timing performances were studied with a Na-22 source, using two-channel systems in which the SiPMs were coupled to scintillator crystals. The best timing resolutions measured were given by Hamamatsu 3×3 mm² area 50 μm pixel size SiPMs. These devices gave timing resolutions of 176 ps (σ) and 227 ps (σ), when coupled to 30 mm-long LaBr₃(Ce) and 5 mm-long LYSO crystals, respectively.

[en] A tracking detector made of scintillating fibers wound on a cylinder is being developed at FNAL, for the experiment E835 (study of the spectroscopy of charmonium formed in pp annihilations, at the Fermilab Antiproton Accumulator). The tracker will be used for the measurement of the polar angle, i.e. of the longitudinal coordinate. The small amount of light from the fibers will be detected by solid state devices (Visible Light Photon Counters) with very high QE, currently being developed and tested by the D0 Fiber Tracking Group at FNAL. This paper reports the performance of a prototype fiber tracker, as measured at FNAL. We present results on light yield/mip, attenuation, efficiency, homogeneity of response and cross-talk. The data are then compared with Monte Carlo predictions. We measured an average number of 14 photoelectrons per mip and a very low noise level. An efficiency greater than 99% is foreseen for the future double layered tracker. (orig.)

[en] Tests of a prototype for the electromagnetic calorimeter (ECAL) of the compact muon solenoid experiment (CMS) at the large hadron collider are described. The basic unit for the endcap ECAL in CMS is a 'supercrystal' of 25 lead tungstate crystals. Results are presented from tests of the first full-sized supercrystal in electron beams and in a 3 T magnetic field. The supercrystal was exposed to electron beams with energies from 25 to 180 GeV. An energy resolution (σ_E/E) of (0.48±0.01)% was measured at 180 GeV

[en] ZEPLIN II is a two-phase xenon detector designed to detect dark matter in the form of Weakly Interacting Massive Particles (WIMPs). Following the first 31-day underground run in Boulby Mine, UK, the collaboration published dark matter limits in January 2007; the first such limits using two-phase xenon technology. We outline the key detector design, performance and results here.