Abstract
It is anticipated that the LHC accelerator will reach and exceed the luminosity of L=2×1034 cm−2s−1 during the LHC Run 2 period until 2023. At this higher luminosity and increased hit occupancies the CMS phase-0 pixel detector would have been subjected to severe dead time and inefficiencies introduced by limited buffers in the analog read-out chip and effects of radiation damage in the sensors. Therefore a new pixel detector has been built and replaced the phase-0 detector in the 2016/17 LHC extended year-end technical stop. The CMS phase-1 pixel detector features four central barrel layers and three end-cap disks in forward and backward direction for robust tracking performance, and a significantly reduced overall material budget including new cooling and powering schemes. The design of the new front-end readout chip comprises larger data buffers, an increased transmission bandwidth, and low-threshold comparators. These improvements allow the new pixel detector to sustain and improve the efficiency of the current pixel tracker at the increased requirements imposed by high luminosities and pile-up. A new DAQ system has been developed based on a combination of custom and standard microTCA parts. This contribution gives an overview of the design and performance of the CMS phase-1 pixel detector.
Highlights
The phase-0 pixel detector of the CMS experiment (1) which operated until 2016 was designed to record efficiently and with high precision the first three space-points near the interaction region up to an instantaneous luminosity of 1.0×1034cm−2s−1 with 25 ns colliding bunch spacing
It is anticipated that the LHC accelerator will reach and exceed the luminosity of L = 2×1034cm−2s−1 during the LHC Run 2 period until 2023. At this higher luminosity and increased hit occupancies the CMS phase-0 pixel detector would have been subjected to severe dead time and inefficiencies introduced by limited buffers in the analog read-out chip and effects of radiation damage in the sensors
The phase-1 pixel detector with modified data acquisition (DAQ) (3), two-phase CO2 cooling and detector control systems (DCS) was installed during an extended year-end technical stop in the beginning of 2017 and it is expected to contribute to high performance tracking in the high luminosity environment of the LHC up to Long Shutdown 3 (LS3)
Summary
The phase-0 pixel detector of the CMS experiment (1) which operated until 2016 was designed to record efficiently and with high precision the first three space-points near the interaction region up to an instantaneous luminosity of 1.0×1034cm−2s−1 with 25 ns colliding bunch spacing. Performance of the CMS Phase 1 Pixel Detector At this higher luminosity and increased hit occupancies the CMS phase-0 pixel detector would have been subjected to severe dead time and inefficiencies introduced by limited buffers in the analog read-out chip and effects of radiation damage in the sensors.
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 call
