LHCb SciFi - Analysis of service performance

In this project report, the analysis of the service performance in the Scintillating Fibre Tracker (SciFi), part of the LHCb experiment at CERN, is summarised. The considered services are used to prevent condensation appearing in the detector. Condensation occurs due to cooling the readout silicon photomultipliers to reduce dark noise. The monophased cooling liquid C6 F14 is used. The services include dry gas flowing through the detector to reduce humidity in the detector, heating by heating wires and the monitoring of outside temperatures. Additionally, the dew point inside the cavern is observed since it has a relation to monitoring the temperatures. The analysis shows that all services are working as expected and it can be assumed that no condensation occurs in the detector and the operating is thus save. During the dew point measurements in the cavern, a constant offset of 2°C was observed. Furthermore, long-term cooling tests using the monophased cooling liquid Novec7100 were performed using a prototype C-frame. Novec7100 has a lower global warming potential is would therefore be preferred. So far, no problems occurred during the tests with several cooling temperatures.