2T 3D Vector magnet

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Scientific Magnetics 2T 3D Vector Magnet

The system comprises:

• Temperature controllers (including a Lakeshore 336)
• 3 power supplies (one for each axis)
• Helium level gauge
• Rotation stage (controlled separately by a Galil axis)
• Motorised needle valve (controlled by Galil analogue output, or Thurlby-Thandar EX355P benchtop PSU)

VI

There is a manufacturer supplied VI and an LVDCOM IOC. There are two versions of the manufacturer's VI and both are stored in SourceSafe at the following location: \LabVIEW Modules\Drivers\Scientific Instruments\3D Magnet\Source Code\. This VI has been used on LARMOR and ZOOM and uses the TTi PSU for needle valve control. When the magnet was originally used on POLREF, an analogue output from the Galil was used.

The settings for the manufacturer VI are stored (and can be edited) in the plain text file: settings.txt. The COM ports are defined in the first section of the file, but it shouldn't be necessary to change these.

Ethernet Switch

The magnet control rack has a small Ethernet switch inside to provide network access to the Lakeshore 336 and MOXA (see below). This will need to be connected to the ISIS network to enable remote control of the magnet.

MOXA NPort

The rack has its own dedicated MOXA NPort 5616 due to the number of devices it uses. When the system is moved between instruments, this MOXA is added to the NPort configuration on the local control machine and its ports assigned to COM101-COM116 (so as not to interfere with common equipment). The control machine IP address should be added to the "accessible IPs list" of the MOXA via the administration webpage (and subsequently removed when the magnet is finished with). Currently, the settings of the dedicated MOXA are:

• IP address : 130.246.37.108
• Port 1 : SMC X PSU
• Port 2 : SMC Y PSU
• Port 3 : SMC Z PSU
• Port 4 : Cryocon 32 temperature controller
• Port 5 : Helium level meter
• Port 6 : TTi EX355P PSU (for needle valve)

Rotation Stage

Standard unit controlled by a Galil axis on both SECI and IBEX instruments. Details:

• +- 370 degrees
• Motor with encoder
• No limit switches - Do not rotate more than 360 degrees too many times or cables will be damaged.
• Home position defined by an index pulse on the encoder

When this magnet was last installed on ZOOM, one of the slit axes was used for the rotation stage as there are no spare cables in the sample area. A batch file exists in the configurations\galil directory of the settings area to set the required PV values for the axis (edit if different axis is used), and a corresponding batch file in the user\users\ZOOM directory of the 'U-drive' will reinstate the settings for the slit axis when the magnet rotation stage is removed.

NB There are plans to install additional cabling into the ZOOM sample area to connect extra motion stages, so this borrowing of an axis may not be needed any longer. Check before altering PV values.

Needle Valve

This is a motorised valve which is controlled via an analogue output from a Galil on SECI instruments (POLREF at least) and a Thurlby-Thandar Instruments EX355P benchtop PSU on IBEX instruments (LARMOR and ZOOM at least). There are two front panel VIs for this purpose, one for each scenario: Vector-control-v16isis.vi for the TTi-EX355P controlled valve and Vector-control-v16isis-Galil-Valve.vi for analogue output controlled valve. Both are in the SourceSafe location mentioned above: \LabVIEW Modules\Drivers\Scientific Instruments\3D Magnet\Source Code\.

If the PSU is to be used, it's possible to check the communication to it via its own VI (located in SourceSafe here: \LabVIEW Modules\Drivers\Thurlby EX355P), once it has been configured with the correct port from the settings.txt file mentioned above.

Lakeshore 336 Temperature Controller

Miscellaneous Information

• The system takes approximately 3 days to reach base temperature