Thursday, the 14th of February 2019, a new laboratory for the testing of silicon particle detectors was opened at the Institute of Physics of the Czech Academy of Sciences. The new laboratory is part of the Detector Development and Data Processing Department (Division of Elementary Particle Physics). It was set up at the premises of the Institute of Information Theory and Automation of the CAS, which are leased by the Institute of Physics. The total floor area of the lab is 52 m2. The laboratory complies with the ISO 7 Cleanroom Standard in accordance with ISO 14644-1 classification system and meets basic conditions of antistatic protection. The laboratory infrastructure includes a dressing room with laminar airflow and a floor area of 2.3 m2, a technical corridor, with a floor area of 12 m2, and a technical room, with a floor area of 6.5 m2.
The laboratory was set up to test strip silicon sensors at the production stage of the ATLAS ITK Project. The main target of the project is a total replacement of the ATLAS Inner Detector for the new High-Luminosity LHC accelerator, which is to be launched at the CERN international laboratory in 2026. The core instrument of the laboratory is the “Probe Station”, which makes it possible to automatically contact different points of the sensor and to measure its electrical properties. Now the laboratory is equipped with two such stations, an older one of Karl Suss PA200 type, and with a brand new Probe Station Tesla. The mechanical properties of silicon sensors, such as their dimensions or planarity, will be examined using the OGP SmartScope CNC 500 metrology station. The sensors are stored in an MP Dry Cabinet IV ST, in which an inert nitrogen atmosphere and relative humidity of less than one per cent are maintained. The Probe Station Tesla and the OGP SmartScope CNC 500 metrology station were acquired with significant funding provided from a programme to support the purchase of high-priced instruments of the Czech Academy of Sciences.
In addition to the testing of non-irradiated silicon sensors, the laboratory will also investigate the radiation damage of silicon sensors induced by intense beams of protons, neutrons and gamma particles. The electrical testing of irradiated sensors is performed at temperatures below -20 °C to avoid inducing uncontrolled changes in the structure of the damaged silicon. For this purpose, the laboratory is equipped with special cold testing set up, where the studied sensors are wire bonded to the prepared test structures using the Delvotec 5330 manual wire bonding station and placed into the Binder MK 53 environmental chamber. The electrical properties of sensors are then tested in the environmental chamber at controlled temperature and relative humidity. The measurement of irradiated sensors may also be performed using Probe Station Tesla which allows the sample to be cooled down to -55 °C.
In addition to individual measuring instruments, the laboratory also includes a distribution system for compressed air, gaseous nitrogen and vacuum. Compressed air is produced by the Renner SLDK-S 7.5 oil-free compressor. Gaseous nitrogen with a purity of 99,99% is prepared from the compressed air by the IMT PN OnTouch 1250 OV nitrogen generator. Technical vacuum is formed using the SCROLLVAC 15 plus oil-free vacuum pump. The instruments are located in the technical room.
The laboratory was set up by the Institute of Physics of the CAS, in cooperation with the Faculty of Mathematics and Physics, Charles University, with significant funds provided by the Czech Academy of Sciences.