Located between the on-detector front-end electronics and the global data acquisition system (DAQ), the off-detector electronics of the CMS electromagnetic calorimeter (ECAL) is involved in both ...detector readout and trigger system. Working at 40 MHz, the trigger part must, within ten clock cycles, receive and deserialize the data of the front-end electronics, encode the trigger primitives using a nonlinear scale, assure time alignment between channels using a histogramming technique and send the trigger primitives to the regional trigger. In addition, it must classify trigger towers in three classes of interest and send this classification to the readout part. The readout part must select the zero suppression level to be applied depending on the regions of interest determined from the trigger tower classification, deserialize front-end data coming from high-speed (800 Mb/s) serial links, check their integrity, apply zero suppression, build the event and send it to the DAQ, monitor the buffer occupancy and send back pressure to the trigger system when required, provide data spying and monitoring facilities for the local DAQ. The system, and especially the data link speed, the latency constraints and the bit-error rate requirements have been validated on prototypes. Part of the system is about to go to production.
The performance of prototype vacuum phototriodes is presented from the first full sized supercrystal array for the CMS ECAL endcaps. The array was exposed to high-energy electrons and tested in ...magnetic fields of up to 3T, in the CERN North area, in July and August 1999. The mean VPT electron yield, normalised to a naked crystal light yield of 8photoelectrons/MeV into an HPMT, was found to be 25electrons/MeV at 3T for devices from Research Institute Electron, 35electrons/MeV for devices from Hamamatsu and 18/23electrons/MeV from Electron Tubes.
Beam test of gamma-ray large area space telescope components Atwood, W.B.; Ritz, S.; Anthony, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2000, Letnik:
446, Številka:
3
Journal Article
Recenzirano
Odprti dostop
A beam test of Gamma-ray Large Area Space Telescope (GLAST) components was performed at the Stanford Linear Accelerator Center in October 1997. These beam test components were simple versions of the ...planned flight hardware. Results on the performance of the tracker, calorimeter, and anti-coincidence charged particle veto are presented.
Tests of a prototype for the electromagnetic calorimeter (ECAL) of the compact muon solenoid experiment (CMS) at the large hadron collider are described. The basic unit for the endcap ECAL in CMS is ...a “supercrystal” of 25 lead tungstate crystals. Results are presented from tests of the first full-sized supercrystal in electron beams and in a 3
T magnetic field. The supercrystal was exposed to electron beams with energies from 25 to 180
GeV. An energy resolution (
σ
E/
E) of (0.48±0.01)% was measured at 180
GeV.
A prototype of the trigger and digital processing electronics for the electromagnetic calorimeter of the CMS experiment, coupled to a prototype of the PbWO
4 crystal calorimeter, was tested during ...summer 1996 in the H4 beamline at the CERN SPS. A very successful operation was achieved for this system, which runs in synchronous and pipelined mode at the LHC clock frequency, and performs the basic trigger and data acquisition functions needed in the CMS electromagnetic calorimeter. The performance of the trigger front-end electronics is well within the established requirements: a highly efficient bunch-crossing identification (>99.9%), a good trigger-energy resolution (
σ/E∼9%/
E
⊕2%
) and a highly efficient electron cluster shape identification (∼99%) have been achieved. The FERMI digitising system based on a dynamic analog compressor and a sampling ADC showed a very good performance, in particular the energy resolution for 150
GeV electrons was 0.54%, equal to the resolution obtained with a conventional charge integration ADC system.
Located between the on-detector front-end electronics and the global data acquisition system (DAQ), the off-detector electronics of the CMS electromagnetic calorimeter (ECAL) is involved in both ...detector readout and trigger system. Working at 40 MHz, the trigger part must, within 10 clock cycles, receive and deserialise the data of the front-end electronics, encode the trigger primitives using a non linear scale, assure time alignment between channels using a histogramming technique and send the trigger primitives to the regional trigger. In addition, it must classify trigger towers in three classes of interest and send this classification to the readout part. The readout part must select the zero suppression level to apply depending on the regions of interest determined from the trigger tower classification, deserialise front-end data coming from high-speed (800 Mbit/s) serial links, check their integrity, apply zero suppression, build the event and send it to the DAQ, monitor the buffer occupancy and send back pressure to the trigger system when required, provide data spying and monitoring facilities for the local DAQ. The system, and especially the data link speed, the latency constraints and the bit error rate requirements have been validated on prototypes. Part of the system is about to go to production.
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