The high-luminosity upgrade of the ATLAS and CMS experiments includes dedicated sub-detectors to perform the time-stamping of minimum ionizing particles (MIPs). These detectors will be exposed up to fluences in the range of 1.5-2.5 x 10(15) eta(eq)/cm(2) and require a time resolution per detecting layer of 30 ps, for non-irradiated sensors, to 50-70 ps (depending on the exposed fluences) for sensors at the end of their lifetime. To cope with these requirements, the low-gain avalanche diode (LGAD) has been chosen as the baseline detection technology. In this article, an in-depth radiation tolerance study on LGADs manufactured at IMB-CNM using a so-called shallow junction is presented. Proton irradiation at CERN-PS up to fluences of 3 x 10(15)eta(eq)/cm(2) and neutron irradiation at JSI-Ljubljana up to 2.5 x 10(15) eta(eq)/cm(2) were performed. Two different active thicknesses were studied: 35 mu m and 50 mu m. Gain degradation, operation stability, and timing performance were evaluated.

The high-luminosity upgrade of the ATLAS and CMS experiments includes dedicated sub-detectors to perform the time-stamping of minimum ionizing particles (MIPs). These detectors will be exposed up to fluences in the range of 1.5–2.5×1015neq/cm2 and require a time resolution per detecting layer of 30 ps, for non-irradiated sensors, to 50–70 ps (depending on the exposed fluences) for sensors at the end of their lifetime. To cope with these requirements, the low-gain avalanche diode (LGAD) has been chosen as the baseline detection technology. In this article, an in-depth radiation tolerance study on LGADs manufactured at IMB-CNM using a so-called shallow junction is presented. Proton irradiation at CERN-PS up to fluences of 3×1015neq/cm2 and neutron irradiation at JSI-Ljubljana up to 2.5×1015neq/cm2 were performed. Two different active thicknesses were studied: 35μm and 50μm. Gain degradation, operation stability, and timing performance were evaluated.

Low Gain Avalanche Detector (LGAD) is the baseline sensing technology of the recently proposed Minimum Ionizing Particle (MIP) end-cap timing detectors (MTD) at the Atlas and CMS experiments. The current MTD sensor is designed as a multi-pad matrix detector delivering a poor position resolution, due to the relatively large pad area, around 1 mm(2); and a good timing resolution, around 20-30 ps. Besides, in his current technological incarnation, the timing resolution of the MTD LGAD sensors is severely degraded once the MIP particle hits the inter-pad region since the signal amplification is missing for this region. This limitation is named as the LGAD fill-factor problem. To overcome the fill factor problem and the poor position resolution of the MTD LGAD sensors, a p-in-p LGAD (iLGAD) was introduced. Contrary to the conventional LGAD, the iLGAD has a non-segmented deep p-well (the multiplication layer). Therefore, iLGADs should ideally present a constant gain value over all the sensitive region of the device without gain drops between the signal collecting electrodes; in other words, iLGADs should have a 100% fill-factor by design. In this paper, tracking and timing performance of the first iLGAD prototypes is presented.

The two main limiting factors in the accuracy of an optomechanical position monitoring system based on laser sources and photosensors are mechanical transfer between the monitored imaging sensors to the active particle tracking elements and non-straight propagation of the reference laser lines. Laser based alignment systems of Si trackers that use their own tracking detectors as photosensors are not affected by the first factor. Improving the transmittance of Si to infrared beams certainly minimizes the second one. Simulation of the passage of a light beam through a real microstrip detector and analysis of first measurements of samples are presented in this paper.