Thermal Grease Evaluation for ATLAS Upgrade Micro-Strip Detector.

The ATLAS upgrade detector foreseen at the phase 2 upgrade of LHC requires a complete new inner detector using silicon pixel and strip detectors. For both technologies, a specific mechanical and thermal design is required. Such a design may use soft thermal interfaces such as grease between the various parts. One foreseeable use would be between the cooling pipe and the thermal block allowing the strip modules to be decoupled from the mechanical and cooling structure. This note describes the technique used and the results obtained when characterizing a few grease samples. The results have been compared with thermal FEA simulations. A thermal conductivity measurement for each sample could be extracted from the measurements, with a systematic uncertainty of less than 6%. Some samples were irradiated to the expected fluence at sLHC and their resulting thermal conductivity compared with the non-irradiated samples

Performance of the ABCN-25 readout chip for the ATLAS Inner Detector Upgrade

We present the test results of the ABCN-25 front end chip implemented in CMOS 0.25 μm technology and optimised for the short, 2.5 cm, silicon strips intended to be used in the upgrade of the ATLAS Inner Detector. We have obtained the full functionality of the readout part, the expected performance of the analogue front-end and the operation of the power control circuits. The performance is evaluated in view of the minimization of the power consumption, as the upgrade detector may contain up to 70 million of channels. System tests with different power distribution schemes proposed for the future tracker detectors are possible with this chip. The ABCN-25 ASIC is now serving as the prototype readout chip in the developments of the modules and staves for the upgrade of the ATLAS Inner Detector

ATLAS liquid argon calorimeter back end electronics

The Liquid Argon calorimeters play a central role in the ATLAS (A Toroidal LHC Apparatus) experiment. The environment at the Large Hadron Collider (LHC) imposes strong constraints on the detectors readout systems. In order to achieve very high precision measurements, the detector signals are processed at various stages before reaching the Data Acquisition system (DAQ). Signals from the calorimeter cells are received by on-detector Front End Boards (FEB), which sample the incoming pulse every 25ns and digitize it at a trigger rate of up to 75~kHz. Off-detector Read Out Driver (ROD) boards further process the data and send reconstructed quantities to the DAQ while also monitoring the data quality. In this paper, the ATLAS Liquid Argon electronics chain is described first, followed by a detailed description of the off-detector readout system. Finally, the tests performed on the system are summarized

New results on diamond pixel sensors using ATLAS frontend electronics

Diamond is a promising sensor material for future collider experiments due to its radiation hardness. Diamond pixel sensors have been bump bonded to an ATLAS pixel readout chip using PbSn solder bumps. Single chip devices have been characterised by lab measurements and in a high-energy pion beam at CERN. Results on charge collection, spatial resolution, efficiency and the charge carrier lifetime are presented