A vacuum controll instruments are implemented in the cryostat. As a pump functions the HighCube 80eco, as a sensor a PKR 251 connected to a TPG361 is used, all from PFEIFFER Vacuum. A solenoid valve is implemented in the system to separate the cryostat from the pump. As a solenoid valve funtions the 0211 from Bürkert, it is a normally closed device, meaning applying energy will open the device. If it's Powered on it connects the pump to the chamber. Furthermore, the vacuum pump and the solenoid valve are both controlled via the PDU, while the single gauge is controlled via a LabVIEW Script via the server.

First turn the vacuum pump on, and then make sure that the Turbomolacularpump is turned off. Only start the vacuum pump when you are sure that the Turbo is off, then start the compressor pump, when the pressure reaches the lower single digits (5 mbar >) turn the Turbomolacularpump on.

The pressure within the Cryostat is monitored with a Single Gauge TPG361 from Pfeiffer Vaccum, which uses a PKR 251 FPM-sealed, DN 25 ISO-KF gauge sensor. The maximum pressure applies to inert gases and temperatures below 55 °C and is corrosion resistant. The TPG361 is designed for installation to a 19“ rack chassis adapter according to DIN 41494 and provides serial communication via R485 (24V, 5-pin circular), USB and Ethernet interfaces.It is used to measure the pressure inside the chamber.

• Front panel Operation: Manual
• Supported Commands: Communication protocol

The HighCube 80 eco from Pfeiffer is uses as a turbumolacular vacuum pump. It allows for a pressure range below 10e(-7)pa. It is possible to remote controll the pump, for this a RS-485 to LAN converter is installed (Moxa Serial LAN device).

* Manual

===== Flowchart =====¨

For better understanding on how the different components of the vacuum subsystem are linked together, the following scheme is provided: