MA6


MA6 vertical field cryomagnet

Sample space dimensions

see Magnet List

Restrictions

Instrument Field Limit Comment
DMC 6 Tesla
MARS 6 Tesla
TriCS 6 Tesla
PREP 6 Tesla in its trolley, far enough from "Kabelkanal"
HRPT 6 Tesla (measured forces below 200 N vertically and horizontally, even for xy table)
RITA II 6 Tesla with goniometer mounted (goniometer motors removed? - to be verified)
EIGER 6 Tesla with goniometer mounted (also gonio motors mounted)
TASP 4 Tesla with goniometer mounted (need force test for higher field)
6 Tesla without gonio

On EIGER the vertical force was less than 80 N at 4.25 Tesla -> no problem. (force test 2020-09-14 by MZ)

On all other instruments, to be evaluated before first use.

max. Forces on Magnet:

horizontal 500N
vertical 500N

max. goniometer tilt: +-5 deg

Specifications

More Information on intranet page (Drawing): LdmWiki:MA6

Energisation rates (Tesla/min)

Field rangeTraining mode (slow)Normal mode (fast)
below 4.8 T0.1922 0.3844
4.8 ... 6 T0.0641 0.3844

Main Coils

Guaranteed maximum central magnetic field6 Tesla
Current for full field 93.661 A
Homogeneity over 15 mm diameter sphere 1.0 %
Magnet clear bore diameter 50 mm
Nominal inductance 18.13 Henry
Switch heater current for open state 65 mA
Current decay in persistent mode < 1/10000 / h
Distance of magnetic field centre for base of cryostat 165 mm
Neutron split 40 mm
Vertical neutron access on a 15 mm sphere±15 deg
Horizontal neutron access 340 deg

Resistance values (Ohm)

RT 77 K 4.2 K
Magnet coil 48.4 39.4 0.1
Switch heater 114.7112.5104.5
Spare switch heater 112.7110.4103.5
Thermometer on coil (Allen Bradley)317.5385 4560

General

Liquid He evaoration rate (needle vale close, no current)<275 cm3/h
Liquid N2 evaporation rate 300 cm3/h
Useful liquid He volume 22 l
Liquid N2 volume 25 l
Approximate weight 150 kg

Field Homogeneity

MA6/ma6_homogeneity.png

Solved Issues

The following problems seem to be solved after repair at Oxford Instruments (Aug 2010)