Time projection chambers for the T2K near detectors

The T2K experiment is designed to study neutrino oscillation properties by directing a high intensity neutrino beam produced at J-PARC in Tokai, Japan, towards the large Super-Kamiokande detector located 295 km away, in Kamioka, Japan. The experiment includes a sophisticated near detector complex, 280 m downstream of the neutrino production target in order to measure the properties of the neutrino beam and to better understand neutrino interactions at the energy scale below a few GeV. A key element of the near detectors is the ND280 tracker, consisting of two active scintillator-bar target systems surrounded by three large time projection chambers (TPCs) for charged particle tracking. The data collected with the tracker is used to study charged current neutrino interaction rates and kinematics prior to oscillation, in order to reduce uncertainties in the oscillation measurements by the far detector. The tracker is surrounded by the former UA1/Nomad dipole magnet and the TPCs measure the charges, momenta, and particle types of charged particles passing through them. Novel features of the TPC design include its rectangular box layout constructed from composite panels, the use of bulk micromegas detectors for gas amplification, electronics readout based on a new ASIC, and a photoelectron calibration system. This paper describes the design and construction of the TPCs, the micromegas modules, the readout electronics, the gas handling system, and shows the performance of the TPCs as deduced from measurements with particle beams, cosmic rays, and the calibration system

The DIRC Particle Identification System for the BABAR Experiment

A new type of ring-imaging Cherenkov detector is being used for hadronic particle identification in the BABAR experiment at the SLAC B Factory (PEP-II). This detector is called DIRC, an acronym for Detection of Internally Reflected Cherenkov (Light). This paper will discuss the construction, operation and performance of the BABAR DIRC in detail

The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C

SNDICE: a direct illumination calibration experiment at CFHT

International audienceWe present the first results of the SuperNova Direct Illumination Calibration Experiment (SNDICE), installed in January 2008 at the Canada France Hawaii Telescope. SNDICE is designed for the absolute calibration of the instrumental response of a telescope in general, and for the control of systematic errors in the SuperNova Legacy Survey (SNLS) on Megacam in particular. Since photometric calibration will a critical ingredient for the cosmological results of future experiments involving instruments with large focal planes (like SNAP, LSST and DUNE), SNDICE functions also as a real-size demonstrator for such a system of instrumental calibration. SNDICE includes a calibrated source of 24 LEDs, chosen for their stability, spectral coverage, and their power, sufficient for a flux of at least 100 electron/s/pixel on the camera. It includes also Cooled Large Area Photodiode modules (CLAPs), which give a redundant measurement of the flux near the camera focal plane. Before installing SNDICE on CFHT, we completed a full calibration of both subsystems, including a spectral relative calibration and a 3D mapping of the beam emitted by each LED. At CFHT, SNDICE can be operated both to obtain a complete one-shot absolute calibration of telescope transmission in all wavelengths for all filters with several incident angles, and to monitor variations on different time scales