Abstract
The upgrades of ATLAS and CMS for the High Luminosity LHC (HL-LHC) highlighted physics objects timing as a tool to resolve primary interactions within a bunch crossing. Since the expected pile-up is around 200, with an r.m.s. time spread of 180ps, a time resolution of about 30ps is needed. The timing detectors will experience a 1-MeV neutron equivalent fluence of about Φeq=1014 and 1015cm−2 for the barrel and end-cap regions, respectively. In this contribution, deep diffused Avalanche Photo Diodes (APDs) produced by Radiation Monitoring Devices are examined as candidate timing detectors for HL-LHC applications. To improve the detector’s timing performance, the APDs are used to directly detect the traversing particles, without a radiator medium where light is produced. Devices with an active area of 8 × 8mm2 were characterized in beam tests. The timing performance and signal properties were measured as a function of position on the detector using a beam telescope and a microchannel plate photomultiplier (MCP-PMT). Devices with an active area of 2 × 2mm2 were used to determine the effects of radiation damage and characterized using a ps pulsed laser. These detectors were irradiated with neutrons up to Φeq=1015cm−2.
Highlights
The high luminosity upgrade of the CERN Large Hadron Collider (HL-LHC), foreseen to start in 2026, will provide an instantaneous luminosity of up to 7.5 ⋅ 1034 cm−2s−1 with a bunch spacing of 25 ns, and an average pile-up of up to 200 collisions per bunch crossing [1]
To reduce the effects of pile-up on the physics analyses, both the ATLAS and CMS experiments are planning to implement dedicated systems to measure the time of arrival of minimum ionizing particles (MIPs) with an accuracy of about 30 ps [2,3]
These timing detectors will be subjected to radiation levels corresponding to a 1-MeV neutrons fluence (Φeq) of up to 4.9 ⋅ 1015 cm−2 for the goal integrated luminosity of HL-LHC of 4000 fb−1
Summary
The high luminosity upgrade of the CERN Large Hadron Collider (HL-LHC), foreseen to start in 2026, will provide an instantaneous luminosity of up to 7.5 ⋅ 1034 cm−2s−1 with a bunch spacing of 25 ns, and an average pile-up of up to 200 collisions per bunch crossing [1]. By providing the time of arrival information of MIPs, these systems allow for the correct association of particles to their primary vertexes in the case the latter have a proximity in space that renders their separation impossible These timing detectors will be subjected to radiation levels corresponding to a 1-MeV neutrons fluence (Φeq) of up to 4.9 ⋅ 1015 cm−2 for the goal integrated luminosity of HL-LHC of 4000 fb−1. This paper summarizes the characterization of deep diffused Avalanche Photo Diodes (APDs) produced by Radiation Monitoring Devices [4] used as timing detectors for charged particles Studies of these sensors as MIP timing detectors, using an AC-coupled readout, were performed previously and showed promising results [5,6].
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 callMore From: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Disclaimer: 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.
