Abstract
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.
Highlights
In this paper we report on the results of a prototype test of the trigger and digital processing electronics for the electromagnetic calorimeter of the CMS experiment [1]
The data were collected during summer 96 in the H4 beamline at the CERN SPS, where a prototype of the PbWO4 crystal calorimeter of CMS was under test
As for the charge ADC total energy estimate, the energy of the matrix has been computed using the sum of the nine energy values of the crystals. This energy sum is represented by En, as it depends on the number (n) of samples used in the optimal weighted sum
Summary
In this paper we report on the results of a prototype test of the trigger and digital processing electronics for the electromagnetic calorimeter of the CMS experiment [1]. The readout electronics of the CMS electromagnetic calorimeter is required to digitise the analog signals with a precision of 12 bits and to cover a dynamic range above 216. The trigger electronics is required to compute the trigger primitives (trigger tower energy sums, and fine-grain cluster shape variables) at a rate of 40 MHz and to provide the correct bunch crossing assignment, performing the first stage of the CMS synchronous and pipelined calorimeter triggering [2]. The main goals of the test reported here were to validate the concepts used in the digital signal processing on data from the high precision CMS crystal calorimeter, both for triggering and data acquisition purposes. PbWO4 crystals, readout system [5], consisting of a dynamic non-linear analog compressor, a 10-bit sampling ADC, a lineariser look-up table and a readout pipeline memory. The system operated in synchronous and pipelined mode at 40 MHz clock frequency, and data were collected using electron beams with energies ranging from 15 to 150 GeV
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
