Superconducting magnet
The rectangular tail contains the split pair magnet mounted so that the field direction is horizontal and provides:
- 4 sets of optical windows in strain-free mounts
- Choice of 7 (8) T or 10 (11) T at 4.2 (2.2) K
- Homogeneity 0.6% over a 10 mm diameter sphere
- Field sweep rate up to 1 T/min
- Stability in persistent mode < 0.01 %/hour
- Low LHe boil-off with > 100 hour static liquid helium hold time
The magnet tail is designed to reduce the volume of helium around the magnet, and maximise the optical access; there is no liquid helium in the optical path.
Sample temperature and wiring
The standard variable temperature insert (VTI) provides sample temperatures in the range 1.5 - 300 K and a clear sample space of 25 mm diameter. Top loading allows samples to be changed while the system is cold and the magnet is at field.
- Enhanced sample space
- A modified insert is available that allows measurements on samples up to 30 mm diameter, with a restricted temperature range
- 3He low temperature option
- HelioxTL. This 3He insert provides sample temperatures in the range 0.45 - 80 K, supplied either as an alternative to the standard insert or as an interchangeable unit. Changing inserts is an easy operation that takes just a few hours. The sample region has 25 mm diameter access and is fitted with a set of 4 radial Spectrosil B windows in strain-free mounts. The sample rod has a wired 24-way Fischer connector.
Windows
A wide range of window materials can be fitted to the Spectromag to meet specific spectroscopy applications
Sample rods
- The standard sample rod permits ±15 mm axial adjustment and full 360° rotation about the vertical axis. There are 3 electrical (Fischer) 10 way connectors, all of which may be pre-wired
- Special sample rods are also available to provide precision movement of the sample about vertical and horizontal axes
Control
- Automatic control using a stepper motor is usually possible
- All standard electronic items are provided with LabVIEW drivers to allow control of the sample temperature and magnetic field. Integration with other virtual instruments provides full experimental control
Special magnets
- Vertical field split pair magnets - These systems have the magnet oriented with the field axis vertical but are otherwise identical to the standard Spectromag. Special systems are also available for Mössbauer spectroscopy with a vertical cooled source/absorber configuration
- Horizontal field solenoids with RT bores - The standard Spectromag cryostat may be fitted with an alternative tail set containing a horizontally mounted magnet with a room temperature bore; these are particularly suited to beamline experiments. Standard magnets are available to 11 tesla with 50 mm RT bore; samples can be cooled to 2.7 K using a separate continuous flow cryostat
- Vertical field solenoids with axial optical access only - The standard Spectromag cryostat may be fitted with vertical solenoids up to 18 T. These systems have 1.5 - 300 K inserts provided with one set of Spectrosil B quartz windows in the base. Special systems are also available for Mössbauer spectroscopy with a vertical cooled source/absorber configuration
- High homogeneity magnets - For measurements such as optically detected magnetic resonance (ODMR) and electron paramagnetic resonance (EPR), enhanced homogeneity magnets (to 10 ppm) are available.