J.Y. Hemery

Energy resolution and longitudinal shower development in a Si/W electromagnetic calorimeter

Abstract The performance of a silicon/tungsten sandwich calorimeter has been investigated for incoming electron energies between 4 and 49 GeV. The calorimeter has an energy response which is linear to better than 1%, and an energy resolution of σ(E) E = (17.6±0.3)% √ τ E , where τ is the number of radiation lengths of passive material interspaced between two active samplers. The longitudinal shower development has been fitted to a two exponential component fall-off beyond the shower maximum.

Electromagnetic shower development in uranium and tungsten: A comparison of data from a silicon sampling calorimeter

Abstract Longitudinal electromagnetic shower development has been studied in uranium and tungsten using a sandwich calorimeter with silicon as the active medium. Data were taken with incoming electron energies of 2, 4 and 6 GeV. The silicon detectors were operated with depletion layers of both 200 and 70 μm. The energy resolution of the calorimeter was reduced by less than 10–15% when the detectors had depleted layer widths of 70 μm.

The antiproton decelerator: AD

A simplified scheme for the provision of antiprotons at 100 MeV/c based on fast extraction is described. The scheme uses the existing p~ production target area and the modified Antiproton Collector Ring in their current location. The physics programme is largely based on capturing and storing antiprotons in Penning traps for the production and spectroscopy of antihydrogen. The machine modifications necessary to deliver batches of 1/spl times/10/sup 7/ p~/min at 100 MeV/c are described. Details of the machine layout and the experimental area in the existing AAC Hall are given.

The energy response dependence of a silicon sampling calorimeter on the silicon depleted layer width

Abstract The dependence of the energy response of a silicon sampling calorimeter on the depletion depth of silicon detectors has been studied with tungsten as absorber and for incoming electrons with an energy of 4 GeV. The detectors were operated with depletion depths of 40, 70, 100, 125, 150 and 200 μm (by adjusting the reverse bias voltage). The total deposited energy varies linearly with the depleted layer width. However, at large depths (greater than 18 radiation lengths), where the deposited energy is small compared to the total energy, a deviation from linearity is observed.

Silicon detectors and associated electronics oriented to calorimetry

Abstract In electromagnetic calorimetry large-size silicon detectors, employing relatively low-resistivity material, can be used. The improvement in the leakage current performance of these devices enables average depleted layers of widths varying by less than 0.3%. The low noise large capacitance oriented electronics provides a good signal-to-noise ratio for single relativistic particles traversing such a large area detector.

The Antiproton Decelerator: AD

Abstract In view of a possible future programme of physics with low-energy antiprotons, a simplified scheme for the provision of antiprotons at 100 MeV/ c has been studied. It uses the present target area and the modified Antiproton Collector (AC) in its present location. In this report the modifications and the operation are discussed.

Status of the antiproton decelerator: AD

A simplified scheme for the provision of antiprotons at 100 MeV/c in fast extraction is described. The scheme uses the existing p production target area and the modified Antiproton Collector Ring in their current location. Some modifications necessary to deliver batches of 1 × 10 7 antiprotons every minute at 100 MeV/c are described, details of the machine layout and the experimental area in the existing AAC Hall are given.

The CERN PS east area in the LHC era

Experiments planned at the CERN Large Hadron Collider (LHC) will require a well-equipped test area with low momentum (<15 Gev/c) secondary particle beams. These beams will be used to test some of the LHC detectors components (ALICE, ATLAS, CMS, LHC-B). In addition another recently approved experiment (DIRAC) will be installed in the PS East Area. This experiment will require a primary proton beam of 24 GeV/c to test QCD predictions. In this context, the EHNL project (East Hall New Look) has been launched. The major modifications include (i) an extension of the present area with a primary 24 GeV/c beam line, (ii) a new secondary beam line layout with test areas at 3.5, 7, 10 and 15 GeV/c, (iii) an additional irradiation area, (iv) an improved facility for beam sharing between the various users. This paper describes the scope of the project, its new features, the planned facilities and its installation schedule.