The sample stage accepts two water cooled electro-magnets which can be used to provide a continuous magnetic flux density up to 1.5T. Both magnets have the capability to hold an "Orange ILL" type cryostat but the Oxford continuous flow cryostat cannot be held by the Newport magnet The main characteristics of the two magnets are detailed in table below.
Max field at 20mm gap
Longitudinal and transverse
*Relative to the neutron beam direction
The installation of both magnets is a complicated process and should not be undertaken by external users. If requested on the application form the magnet will be installed by your local contact at the beginning of the experimental run. Please discuss your magnetic field requirements with your local contact in advance of any experiment.
Measuring the magnetic field
A "Hirst" teslameter is available in the CRISP cabin to measure the magnetic field strength of the magnet and the neutron guide fields. The hand held unit is simple to operate although care should be taken to ensure the correct Hall probe is used to measure either the longitudinal or transverse magnetic field. The teslameter may also be connected to the RS232 terminal box within the blockhouse for continuous measurement of the field.
Safety and the Newport magnet
The Newport magnet will be installed at the beginning of your experiment by the local contact but there are several safety issues which you should be familiar with before operating the magnet:
The presence of an input voltage to the power supply is indicated by the "Magnet On" sign in the blockhouse. If illuminated then there is the possibility that the magnet is energised and users must ascertain if the magnet is actually powered (measure the field or check the power supply).
The power supply can be immediately shut off by tripping the interrupter switch which is clearly marked on the CRISP blockhouse wall.
The electrical connection for the magnet is located in the CRISP blockhouse. It is essential that if the magnet needs to be connected/disconnected then the power must be shut-off either at the power supply or by tripping the interrupter switch.
Cooling water must flow through the magnet at all times, even at low operating currents.
When energised care should be taken to avoid introducing magnetic materials (e.g. watches, screwdrivers) near to the pole pieces.
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