Vacuum & Cooling

Due to the occasional failure of the thermal monitoring unit (see above) which includes the measurement of the water temperature of the PTR cooler of NOTCam a second alternative system has been developed as a back-up in case the TMS unit fails. The new monitoring system talks over Ethernet and uses a digital temperature sensor and has been found to track the old TMS calibrated sensor well.

The supply tube of the PTR was cracked just after the point were it is fixed to the instrument and Helium was leaking. The tube needed to be welled, cleaned, and refilled with Helium. The hoses have been attached a bit differently to the instrument in an attempt to minimise stresses as far as possible when moving the instrument. The plan is to purchase one extra hose to have a spare that can be readily exchanged with a broken one next time we get a leak. As it is now, several hours of repair work is needed when this happens. A new quotation from Kelvin International must be asked, but the one we got in 2010 for a 12.5 m long flexible steel hose (including couplings and filled with 99.999% Helium gas), was at $1090 plus transport.