EPPD: Particle Detector for the LHCb-ECAL Upgrade 2 Featuring ~10 Picosecond Timing

Phase II LHCb Electromagnetic Calorimeter (ECAL) upgrade for high luminosity flavor physics program at LHC is projected to overcome limitations of the present ECAL system. Upgraded ECAL modules should be tolerant to a radiation dose of about 1 MGy, capable of timing resolution of about 10 psec and energy resolution of about 10% for 5-100 GeV electrons. The choice for the central part of ECAL is presently thought to be implemented as a sampling calorimeter with dense tungsten-based converter and radiation hard crystal scintillator. Concerning the particular structure type, it was found that the Spaghetti Calorimeter (SPACAL) concept based on GAGG:Ce or YAG:Ce scintillators meets the requirements on radiation hardness. However, the timing resolution for experimental SPACAL modules read out with conventional PMTs is still far from the required goal. We propose to adopt the well-established High Rate Picosecond Photon Detector (HRPPD) technology for achieving the required timing capability for SPACAL. This will be realized by developing a dedicated radiation hard ECAL Picosecond Particle Detector (EPPD) units featuring 6 um pore ALD functionalized borosilicate glass MCPs. EPPD units will be integrated into the SPACAL modules to provide 10-20psec timing resolution. MCP-PMTs with 6 um pore MCPs will enable new techniques in HEP, homeland security (non-proliferation) sensors to screen vehicles and cargo for Special Nuclear Materials (SNMs) and scientific detectors for astrophysics, time-of-flight mass spectrometry and medical imaging products including detectors for positron emission tomography (PET scanning) that are not achievable with conventional small area MCP-PMTs. ECAL Phase II upgrade will require about 50 square meters of detector coverage that translates to about 3,500 EPPDs. With production volume of more than 1000 devices, the EPPD price will be conservatively reduced to $100 per cm2 of active area.