The Slow Control System for the Large Prototype

For every gaseous detector exists the inherent need of controlling or at least monitoring the conditions of the employed gas and the detector itself.
Since composition and physical condition (pressure, temperature) of the gas as well as operational voltages and environmental conditions are changing and do on the other hand affect the operation of the detector, a gas system was set up at the testbeam area 24/1 at DESY.

With the slow control system developed for the Large Prototype, it will possible to monitor water and oxygen content of the gas (the two main pollutions), pressure, temperature, fill level of the gas bottles and gas flow. The latter can also be controlled. The system is constantly being improved and adapted to new needs. It is planned to extend the LCTPC system towards a full slow control system for the experiment and incorporate it into a run control system.

The measurements are digitized by the system and and read out by the Distributed Object Oriented Control System (DOOCS). The system itself is housed in a 19” rack, including the piping for the gas, such that a relatively flexible operation is possible and the system can be moved to various measuring locations with sufficient ease.