-- EstherBabetteMenz - 2021-04-29

Vacuum at the CRYRING@ESR Particle Detectors

There are currently two particle detector setups in operation at CRYRING@ESR. Both are located downstream from the electron cooler and are used to detect downcharged product ions. The YAP:Ce scintillation detector (YR03DS1HA) sits directly behind the first dipole magnet after the cooler and is used for light ions in low charge states (including neutral reaction products). The CEM detector (YR04DS2HA) is located further down the straight section (YR04) and is used for heavier, highly charged ions (up to and including He-like uranium). Both detectors are used in recombination experiments at the electron cooler, including dielectronic recombination measurements.

Both detectors have self-contained vacuum chambers that can be closed of from the main ring vacuum while the detectors are not in use or to facilitate easy replacement of components (e.g. scintillation crystals).

Vacuum Read-out

The vacuum read-out of the detector chambers (as well as the two window chambers on either side of the electron cooler) can be found here. The scintillation detector is represented by the red line (YR03DS1HA) and the CEM detector by the green line (YR04DS2HA). Both should be in the range of 10^-11 mbar during operation. The vacuum read-out should be closely watched while the pneumatic drive is operated in automatic mode.

Closing the valves

Important: Before closing the valves make sure that the detector arm is fully retracted to the outside position of the step motor (not the pneumatic drive). Closing the valve while the detector is in the way will lead to substantial damage and further vacuum leaks. Instruction for stopping the pneumatic drive and driving to the outside positon with the step motor can be found here.

Close the valve using the hand wheel until fully closed. The resistance becomes noticeably bigger during the last few rotations, be sure to keep going until the end position is reached.