pulsed_cap_disch

Power Supply:: The capacitor bank provides 1.1 megajoules at 10 kV. There are 8 sub-modules with 4 in use and 4 in reserve. Presently the system uses ignitron switches for both the initial switching and the crowbar.
The switching noise is about 0.05% of the magnet's dB/dt, except for switching transients. Recent deHaas-van Alphen measurements on gold in a stainless steel cryostat enjoyed a signal to noise ratio greater than 100 at 4 K.
Magnet Cells:: Different pulsed field magnets can be installed interchangeably in either of three magnet cells. The magnet is cooled to 77 K before being pulsed. The cool-down time following a pulse at the highest field is about one hour. A magnet dewar with optical windows is available for through-bore optical transmission experiments.

Magnet and Cryostat Characteristics:

50 T, 24 mm bore, 20 ms total pulse length, He-4 cryostats, He-3 cryostat with base temperature of 400 mK, dilution refrigerator with base temperature of 30 mK (60 mK following pulse)
60 T, 14 mm bore, 20 ms total pulse length, He-4 glass cryostat
45 T, 24 mm bore, 20 ms total pulse length, higher homogeneity magnet (for pulsed field NMR)

Magnets Planned for future installation:

* 42 T, 24 mm bore, long decay time magnet, (500 ms) expected early in 1995.