TORCH: A Cherenkov Based Time-of-Flight Detector

TORCH is a novel high-precision time-of-flight detector suitable for large area applications and covering the momentum range up to 10 GeV/c. The concept uses Cherenkov photons produced in a fused silica radiator which are propagated to focussing optics coupled to fast photodetectors. For this purpose, custom MCP-PMTs are being produced in collaboration with industrial partners. The development is divided into three phases. Phase 1 addresses the lifetime requirements for TORCH, Phase 2 will customize the MCP-PMT granularity and Phase 3 will deliver prototypes that meet the TORCH requirements. Phase 1 devices have been successfully delivered and initial tests show stable gain performance for integrated anode current >5 C/cm2 and a single photon time resolution of ≤ 30 ps. Initial simulations indicate the single photon timing resolution of the TORCH detector will be ∼70 ps

TORCH: A Cherenkov Based Time-of-Flight Detector

TORCH is a novel high-precision time-of-flight detector suitable for large area applications and covering the momentum range up to 10 GeV/c. The concept uses Cherenkov photons produced in a fused silica radiator which are propagated to focussing optics coupled to fast photodetectors. For this purpose, custom MCP-PMTs are being produced in collaboration with industrial partners. The development is divided into three phases. Phase 1 addresses the lifetime requirements for TORCH, Phase 2 will customize the MCP-PMT granularity and Phase 3 will deliver prototypes that meet the TORCH requirements. Phase 1 devices have been successfully delivered and initial tests show stable gain performance for integrated anode current >5 C/cm2 and a single photon time resolution of ≤ 30 ps. Initial simulations indicate the single photon timing resolution of the TORCH detector will be ∼70 ps

Multianode photomultiplier tube studies for imaging applications

Highly efficient and position sensitive photon detection is essential in a variety of applications from particle identification in fundamental nuclear and particle physics research, to radionuclide imaging in healthcare. Due to their position sensitivity and high packing fraction, the Hamamatsu H8500 and H9500 multianode photomultiplier tubes (MAPMTs) are promising candidates for such applications and have thus been studied through precision laser scans at several light intensities. This has revealed signal and crosstalk dependencies upon constructional features of the MAPMTs. Both MAPMTs feature a common last dynode output signal, which can be used for self-triggering. The strength and timing of this signal have been investigated for the H8500 MAPMT, yielding similar dependencies upon MAPMT construction and standard deviation time resolutions of 67.5 ps and 154.4 ps for 20 and single photoelectron signals respectively

Factors influencing texture modifying characteristics of selected strains of lactic acid bacteria

SIGLEAvailable from British Library Document Supply Centre- DSC:DX176304 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Micro-channel plate photon detector studies for the TORCH detector

The Time Of internally Reflected Cherenkov light (TORCH) detector is under development. Charged particle tracks passing through a 1 cm plate of quartz will generate the Cherenkov photons, and their arrival will be timed by an array of micro-channel plate photon detectors. As part of the TORCH R&D studies, commercial and custom-made micro-channel plate detectors are being characterized. The final photon detectors for this application are being produced in a three-phase program in collaboration with industry. Custom-made single-channel devices with extended lifetime have been manufactured and their performance is being systematically investigated in the laboratory. Optical studies for the preparation of beam and laboratory tests of a TORCH prototype are also underway

Radiation hardness study on fused silica

Radiation hardness tests have been carried out on fused silica samples of the highest optical grade from three different manufacturers (Suprasil, Lithosil and Corning). The samples were irradiated with protons in order to emulate the expected accumulated radiation damage over the entire life span of the future PANDA experiment. Changes in optical properties were the primary focus of this study. The optical transmission over a broad wavelength band ranging from UV to visible light was investigated using a commercial spectrophotometer. In addition, changes of the polished surface were studied using an interferometer. No evidence for changes in transmission and surface quality was found within the obtained precision