guest ::
| Home > Publications database > Improvement and calibration of a thermal conductivity measurement setup |
| Home > Publications database > Improvement and calibration of a thermal conductivity measurement setup |
| Bachelor Thesis | PUBDB-2025-05375 |
; ;
2025
Abstract: The outer tracker of the Compact Muon Solenoid (CMS) Detector will be upgraded as part of the upgrade of the Large Hadron Collider (LHC) to the High-Luminosity LHC.The Tracker Endcap Double-Discs (TEDD), that are part of the outer tracker are built and integrated with modules at DESY. The CMS detector and with it the TEDD will be cooled to evacuate the generated heat of the modules, to minimize their leakage current due to the heavy irradiation from the passing through particles and avoid thermal runaway. Therefore, a good thermal coupling of the modules to the cooling structure of the TEDD is necessary. This creates the necessity for new materials, that have a high thermal conductivity, while having a large radiation length and a small density. A custom setup for thermal conductivity measurements was developed, with which the thermal conductivity of suitable materials can be precisely measured. This bachelor thesis provides an overview about the operation of the custom thermal conductivity measurement setup and the measurement process.Additionally, the setup is improved as a part of the thesis by installing a Peltier element based temperature control, to enable faster and more frequent measurements. The used thermistors and the full setup are calibrated as preparation for a calibration campaign in the context of the Detector Research and Development Collaboration for Mechanics & Cooling of Future Vertex and Tracking Systems (DRD8), that has the objective to make results comparable to those of other institutes.The thermistors, that are used in the setup, are calibrated for a temperature range from 2 ◦C to 30 ◦C. For one thermistor, the decision to exclude it from the data analysis was confirmed. For the other thermistors, the standard deviation of the temperature difference between the corrected temperature measurements and the reference temperature measurement is below 0.016 ◦C. The proportional-integral-derivative (PID) control for the Peltier element is calibrated to ensure a more stable temperature control, that prevents large fluctuations. The values Kp = 80, TN = 20 and TV = 5 were determined for the PID parameters proportional gain Kp, integral time TN and derivative time TV to enable a control with these characteristics. The standarddeviation of the temperature control was achieved to be below 0.01 ◦C. The prevention of larger fluctuations significantly shortens the time one measurement takes to achieve morefrequent measurements.To calibrate the modified setup, brass alloy CW614N and sapphire glass samples were measured. The results were compared to the respective nominal value and the mean calibration factor ccal = 0.984 was extracted. That calibration factor will be multiplied with the measured thermal conductivity of future measurements to obtain the resulting thermalconductivity.
|
The record appears in these collections: |
PDF
PDF (PDFA)