Performance of fully instrumented detector planes of the forward calorimeter of a Linear Collider detector

Abstract

Detector-plane prototypes of the very forward calorimetry of a future detector at an e + e − collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.

Performance and Molière radius measurements using a compact prototype of LumiCal in an electron test beam

“…All detector planes, for both the calorimeter and the tracker, were powered with a reverse bias voltage of 120 V . This bias voltage is about 2 to 3 times the depletion voltage [11], but well below the breaking voltage of these silicon sensors.…”

“…Results of beam tests and more details about the sensor can be found in Ref. [11,6]. The first prototype of a LumiCal detector plane, which has been successfully used in a multi-layer configuration [6], had a thickness of about 4 mm and only 32 pads were connected to the readout electronics.…”

“…The effect due to the usage of one single radius R 0 in equation (11) for the calculation of En is estimated by selecting a narrow range of the particles impact position around the sensor pad with the radial index n = 45. The relative changes of the effective Molière radius is within 0.13 mm.…”

Photon structure functions at the ILC energy range

“…The analysis used the information related to the forward detectors, tracking detectors and calorimeters which are parts of the ILD (International Large Detector) detector concept [3]. The results of PYTHIA 6.4 [19] Monte Carlo studies as well as those obtained using the reconstructed kinematic variables in the case of tagging the scattered electrons in deep inelastic eγ scattering with the special calorimeters in the very forward region, LumiCal 2 and BeamCal 3 detectors [20], are presented in Figure 2. These forward detectors allow scattered electron tagging in the regions 31 -78 mrad and 5.8 -43.5 mrad respectively.…”

Recent progress with very forward calorimeters for linear colliders

“…This work is aimed to use the same LumiCal sensor, which was studied in labs and in test-beams. The sensor was briefly described in section 2, more information can be found in [8,13]. It is essentially an array of diodes produced on one side of high resistivity n-type silicon wafer surrounded by three guard rings.…”