Speaker
Yu Takahashi
(University of Tsukuba (JP))
Description
The Large Hadron Collider (LHC) is planned to be upgraded to High Luminosity LHC (HL-LHC) in ten years. The upgrade aims at increasing the luminosity up to 5.0 × 10^34 cm^-2 s^-1 where the strip sensors will receive about 20 Gy/h of radiation. We are designing n-strip on p-bulk microstrip sensors for the ATLAS experiment at the HL-LHC. The sensors have been shown to be radiation tolerant up to the fluence of 1.0 × 10^15 n/cm^2, which is maximum fluence expected at the HL-LHC, from the irradiation studies using protons, neutrons and other particles.
We carried out series of Co gamma irradiation studies to investigate the stability of their IV and isolation properties under irradiation at the expected rates. Non-irradiated sensors tend to lose the IV stability within receiving about 20Gy, which is more evident at higher biases and higher irradiation rates. After they survive at a minimum required bias, they recover the stability as they accumulate the dosage and become sufficient to be operated in the HL-LHC radiation environment. These results indicate that early unstable surface condition is stabilized by radiation. The strip isolation is degraded by irradiation but stays stable within a usable level.
Authors
K Hara
(University of Tsukuba (JP))
Yu Takahashi
(University of Tsukuba (JP))
