Proton detection with large-acceptance scintillator detection systems

Two highly segmented plastic-scintillator arrays have been developed for proton detection in electron scattering experiments. The detectors subtend solid angles of 225 and 550 msr and cover energy ranges of 50-225 and 25-165 MeV, respectively. The charge and arrival time of each photomultiplier signal are digitized by flash ADCs and temporarily stored in a dual-port memory. The readout parameters are computer controlled, tuned, and monitored. These detectors have been employed in (e, e′p) and (e, e′pp) experiments for proton emission angles greater than 30° and for luminosities up to 1

Virgo: a laser interferometer to detect gravitational waves

This paper presents a complete description of Virgo, the French-Italian gravitational wave detector. The detector, built at Cascina, near Pisa (Italy), is a very large Michelson interferometer, with 3 km-long arms. In this paper, following a presentation of the physics requirements, leading to the specifications for the construction of the detector, a detailed description of all its different elements is given. These include civil engineering infrastructures, a huge ultra-high vacuum (UHV) chamber (about 6000 cubic metres), all of the optical components, including high quality mirrors and their seismic isolating suspensions, all of the electronics required to control the interferometer and for signal detection. The expected performances of these different elements are given, leading to an overall sensitivity curve as a function of the incoming gravitational wave frequency. This description represents the detector as built and used in the first data-taking runs. Improvements in different parts have been and continue to be performed, leading to better sensitivities. These will be detailed in a forthcoming paper. © 2012 IOP Publishing Ltd and Sissa Medialab srl

Seismic attenuation system for the external injection bench of the Advanced Virgo gravitational wave detector

In November 2011 a major upgrade of the Virgo gravitational wave detector was started. After these improvements the detector's sensitivity will have increased by an order of magnitude, increasing the expected event rate by 103 compared to its predecessor. Extensive noise studies showed that this improvement can only be accomplished if a number of optical benches, hosting ancillary optics and optical sensors for the alignment of the interferometer, are isolated from seismic ground motion to reduce the amount of beam jitter and control noise they introduce. Here we present the first of these systems: the External Injection Bench Seismic Attenuation System, or EIB-SAS, which is able to reduce seismically induced motion of the external injection bench (last bench before laser beam enters the vacuum system) by more than 40 dB above 10 Hz in 6 degrees of freedom

Seismic attenuation system for the external injection bench of the Advanced Virgo gravitational wave detector

In November 2011 a major upgrade of the Virgo gravitational wave detector was started. After these improvements the detector's sensitivity will have increased by an order of magnitude, increasing the expected event rate by 1

A polarized 3He internal target for storage rings

A polarize

A small-angle large-acceptance detection system for hadrons

The performance of a segmented large-acceptance detector, capable of measuring particles at small forward angles, is presented. The Small-Angle Large-Acceptance Detector (SALAD), was built to handle very high rates of particles impinging on the detector. Particles down to a few MeV can be detected with it. The position of charged particles is measured by two Multi-Wire Proportional Chambers while scintillator blocks are used to measure the energy of the detected particle. A stack of thin scintillators placed behind the energy detectors allows for a hardware rejection (veto) of high-energy particles going through the scintillator blocks. (C) 2000 Elsevier Science B.V. All rights reserved

Vertical and horizontal seismic isolation performance of the Advanced Virgo External Injection Bench Seismic Attenuation System

AbstractDuring the combined commissioning and science run of Virgo in 2010, an extensive noise study revealed that vibrations of some of the injection/detection optics on the external injection bench (EIB) made a significant contribution to the interferometer's noise budget. Several resonances were identified between 10 and 100Hz of the EIB support structure and between 200 and 300Hz of the optics mounts. These resonances introduced a significant amount of beam jitter that would limit the sensitivity of Advanced Virgo. This beam jitter needed to be reduced for Advanced Virgo to reach its full potential. To eliminate this noise source we developed a seismic attenuation system to isolate the EIB from ground vibrations: EIB-SAS. It employs vertical and horizontal passive seismic filters based on negative stiffness technology to attenuate seismic noise by 40dB above 10Hz. The isolation capabilities of the system have been characterized up to 400Hz with the aid of a custom designed piezoelectric actuated shaking platform. The results of the vertical and horizontal transfer function measurements are presented

Performance of a hydrogen/deuterium polarized gas target in a storage ring

The performance of a hydrogen/deuterium polarized gas target in a storage ring is presented. The target setup consisted of an atomic beam source, a cryogenic storage cell and a Breit-Rabi polarimeter. High frequency transition units were constructed to produce vector polarized hydrogen and deuterium, or tensor polarized deuterium. The nuclear-polarized gas was produced in an atomic beam source (ABS) and injected into the feed tube of a storage cell. The electron beam encountered no window materials when passing through the target which resulted uncertainities in scattering from contaminants were small