Characterization and Validation of Irradiated Novel Vacuum Sensors

The High-Luminosity Large Hadron Collider (HL-LHC) upgrade will expose vacuum systems to radiation levels ten times higher than current operations. This increase necessitates radiation-tolerant vacuum sensors for reliable detector performance. However, commercially available radiation-hard sensors cost approximately 2500 CHF per channel including readout electronics, making large-scale deployment prohibitively expensive. Previous cost-reduction efforts involved relocating readout electronics to low-radiation areas while keeping sensor heads in the vacuum system. Although this approach reduced radiation damage to electronics, it required extensive manual labor and offered limited cost savings.

Recently, low-cost Pirani gauges without integrated electronics have become available at a fraction of the cost. While manual labor is still required to establish the readout system, sensors can be easily swapped without modifications once the system is integrated. Unlike traditional Pirani sensors that rely on pressure-dependent resistance, these new sensors use multiple thermocouples that generate pressure-dependent voltages within the vacuum environment.

Although this price reduction would enable higher granularity monitoring and improved redundancy, the radiation tolerance of these sensors remains uncharacterized. The project addresses this knowledge gap through systematic testing: constructing a calibrated test setup, establishing baseline sensor performance, exposing sensors to controlled radiation doses, and evaluating post-irradiation characteristics.