MuSR Graphical User Interface: deltat
2.0
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The Oxford Instruments VARIOX cryostats are used on the GPD and DOLLY MuSR instruments. They can be used as usual so-called static helium-flow cryostat with a sample stick insert.
They can be also used in combination with the HELIOX insert, which is an 3He sorbtion pump system.
On the DOLLY instrument, the temperature of the Variox cryostat is controlled by a standard Lakeshore 340 temperature controller. The needle-valve of the cryostat is controlled by a RVC300 controller reading the actual value of the helium flow. The needed helium-flow setpoint is determined by a separated "Flow Control" front-end which can either calculate the flow automatically or use a given setpoint. See the available "Quick References DOLLY".
On the GPD instrument, the Variox cryostat is controlled by a LabView application running on a PC located near the instrument. In turn this LabView application can be controlled by the deltat
GUI through a MIDAS front-end. When using the Variox cryostat alone, the MIDAS front-end and LabView application should be configured accordingly (see section Configuring the MIDAS front-end).
Usually, the user can set the temperature of the Variox and read the cryogenic levels.
If the tab Modify Devices
is selected a list of the available devices will appear. The Variox/Heliox Cryostat can be selected and a button Modify
will be available.
By hitting the button Modify
, a first dialog appears giving the possibility either to change the setpoint (Modify Temperature
).
If the checkbox Update Title
is active, the temperature setpoint in the title of the run will be updated by the present temperature controller when a new setpoint is choosen. Also the temperature average values calculated by the present temperature controller will be written in the header of the run (if correctly set in the MIDAS database – usually done by the Instrument Scientist). Note that the user should ensure that no other temperature controller will update the run title.
OK
.When using the Variox cryostat with the Heliox, the MIDAS front-end and LabView application should be configured accordingly (see see section Configuring the MIDAS front-end).
Usually, and after the condensation of the 3He liquid, the Variox is kept at the lowest temperature (using the Lakeshore temperature controller on DOLLY or through the LabView application on GPD) and solely the temperature of the Heliox is changed from the deltat
GUI application (the possibility to change the Variox setpoint from deltat
beeing disabled on the GPD instrument).
If the tab Modify Devices
is selected a list of the available devices will appear. The Variox/Heliox Cryostat can be selected and a button Modify
will be available.
By hitting the button Modify
, a first dialog appears giving the possibility to change the setpoint (Modify Temperature
).
If the checkbox Update Title
is active, the temperature setpoint in the title of the run will be updated by the present temperature controller when a new setpoint is choosen. Also the temperature average values calculated by the present temperature controller will be written in the header of the run (if correctly set in the MIDAS database – usually done by the Instrument Scientist). Note that the user should ensure that no other temperature controller will update the run title.
OK
.The Oxford Instrument LabView application controls the Heliox insert and also the Variox cryostat on the GPD instrument. This application controls the needed temperature controllers (ITC 503's). During normal operation, the user controls the temperature of the cryostat and/or insert through a MIDAS fron-end process, which communicates with the LabView application. This MIDAS front-end is fully integrated into the deltat
GUI application.
Prior to control the Varix/Heliox system, the LabView application should be setup correctly and ready to communicate with the MIDAS front-end.
Ask the instrument scientist for advices.
Notes for the instrument scientist:
/Equipment/tempvariox/Settings/Devices/OXFORDVARIOXout/DD/ITC Variox Used
/Equipment/tempvariox/Settings/Devices/OXFORDVARIOXout/DD/ITC Heliox Used
odbedit
or through the WEB interface, by looking at the tree:http://psw404:8081/Equipment/tempvariox/Settings/Devices/OXFORDVARIOXout/DD
http://psw403:8081/Equipment/tempvariox/Settings/Devices/OXFORDVARIOXout/DD
/Equipment/tempvariox/Variables/Output[30]
/Equipment/tempvariox/Variables/Output[31]
odbedit
or through the WEB interface, by looking at the tree:http://psw404:8081/Equipment/tempvariox/Variables
http://psw403:8081/Equipment/tempvariox/Variables
Output[30]
and Output[31]
variables correspond to the variables ITC_Variox_Setpoint_Used
and ITC_Heliox_Setpoint_Used
, respectively