The Baby-DEMO small scale low temperature CO2 cooling demonstrator for ATLAS ITk PIXEL at CERN
Author
Zwalinski, L.
Bojdol, K.
Bortolin, C.
Dziurdzia, P.
Giakoumi, D.
Godlewski, J.
Ilyashenko, I.
Kantor, R.
Klimczyk, L.
Kuczek, T.
Niezgoda-Zelasko, B.
Puppo, R.
Rossi, C.
Verlaat, B.
Vogt, S.
Data powstania
2017
Language
English
Comments
Forum on Tracking Detector Mechanics 2017 July 3-5 2017, Marseille, France
Abstract
The evaporative CO2 has been selected as a detector cooling technology for Phase II upgrade of the silicon detectors at CERN. In order to provide input to the ATLAS Pixel TDR about minimum attainable cooling temperature by the end of 2017 as it will have an impact on technological choices for the new detector sensing elements. ATLAS together with contribution of CMS, has launched a dedicated detector cooling R&D study called Baby-DEMO. The Baby-DEMO will be the demonstration of a typical 2PACL CO2 plant to operate at the lowest temperature ever achieved. It will investigate capability to reach an operational temperature down to -45°C taking into account that at -56°C CO2 freezes and CO2 pumps require to operate with safe sub cooling margin. The target is to bring the on evaporator temperature down to -40°C or lower. System composed of cooling plant, low temperature chiller and typical distribution beyond ATLAS PP2 will be constructed at CERN. The real size ATLAS mock-up will be used to hold realistic manifolding as it’s critical path might have strong impact on cooling performance. Additionally the Baby-DEMO programme address study of the high power flexible vacuum insulated transfer lines and warm nose boiling enhancement as possible solutions for phase 2 upgrade. This presentations will show the system design including CO2 plant, primary chiller and typical distribution. We will describe challenges and solutions that we put in place to achieve lowest temperature operation. Results will become of a great value for Phase II upgrade cooling systems design for both for ATLAS and CMS.
