sinqwiki: MA09SpecificationsManual

MA09SpecificationsManual

5 Specifications and Test Results

5.1 Magnet Specification

5.1.1 Main Magnet

Symmetric Energisation:

Guaranteed maximum central magnetic field at 4.2K: 8.0 Tesla Guaranteed maximum central magnetic field at 2.2K: 9.0 Tesla

Current for central field of 8 T	100.75 A
Current for central field of 9 T	113.34 A
Field / Current ratio	0.0794 T/A (794 Gauss/Amp)
Nominal inductance	88 Henries

Asymmetric Energisation:

Guaranteed maximum central magnetic field at 4.2K	4.0 Tesla
Current for central field of 4 T	91.35 Amps
Field / Current ratio	0.0438 T/A (438 Gauss/Amp)
Nominal inductance	46 Henries

Neutron access

340 degrees in horizontal plane
+-6 degrees onto 24 mm on axis in vertical plane.

Switch heater current for open state	75 mA

5.1.2.Resistance Values (Ohm)

Carbon resistors for lambda point refrigerator
	Room Temp	77 Kelvin	4.2 Kelvin
Magnet resistance Start-End Sym	47.4	35.9	0.1
Magnet resistance Start-End Asym	45.6	30.8	0.1
Persistent mode switch resistance	50	210	205
Switch heater resistance	214
Magnet to cryostat isolation (at 500v)	>20 M	>20 M	>20 M
Main magnet to switch heater	>20 M	>20 M	>20 M
R1	142.0	163.0	976.0
R2	153.7	176.6	1021
R3	166.8	189.3	1015
R4	164.9	185.5	1062

5.2 Magnet Energisation

Energisation Rate

Symmetric Energisation:

Energisation Current (A)	Energisation Rate (A/min)
0 to 75	3.0
75 to 90	2.0
90 to 100.75	1.0
100.75 to 113.34 Important: only at 2.2 K!	0.5

Asymmetric Errergisation:

Energisation Current (A)	Energisation Rate (A/min)
0 to 75	5.0
75 to 91.35	2.0

Achieving Persistent Mode

Maximum rate of change of current in the magnet current leads with the magnet in persistent mode (switch heaters off) is: 120 Amps/minute. This rate is programmed into the PS120-10.

For TAS7 users:

Note: For fields > 5T, tilt and translation motors GU,GL,TU,TL must be removed. This prevents the problem of the magnet pulling sideways and touching the inner LN2 shield.

5.3 Typical Lambda Point Performance

Resitance values of carbon resistors

R1 (kOhm)	R2 (kOhm)	R3 (kOhm)	R4 (kOhm)	approximate time after starting operation (min.)	Pressure (mbar)
0.976	1.021	1.015	1.062	0	1000
0.976	1.022	1.153	1.311	10	45
0.981	1.448	.1343	1.492	20	40
0.989	1.670	1.568	1.721	30	40
1.015	1.997	1.900	2.051	40	30
1.100	2.860	2.595	2.780	50	30
1.097	3.252	3.140	3.272	60	30
1.190	4.075	4.115	4.321	70	30
3.840	4.080	4.390	5.130	80	30
					Start to energize magnet from 8 T to 9 T.
3.850	4.090	4.420	5.640	115	30
					9 Tesla achieved
3.860	4.100	4.440	5.930

5.4 Cryogenic Performance

Useful helium capacity	45 litres
Nitrogen capacity	43 litres
Typical liquid helium boil off rate at 4.2 K (no current in magnet leads, VTI needle valve closed)	330 cc/hr
Typical liquid nitrogen boil off	630 cc/hr
" when current in the leads	< 750 cc/hr

5.5 Appendix

Allen-Bradley and Rhodium-Iron Temperature Sensor Characteristics

Typical values of temperature versus resistance for an Allen-Bradley carbon resistor with nominal resistance at room temperature of 100 ohms and 270 ohms.
Typical values of resistance versus temperature for a 4-wire Rhodium Iron sensor with a nominal resistance of 27 ohms at 273 Kelvin.
Please note that this sheet is a guide for cooldown monitoring purposes only, and is not a substitute for a full calibration.

Temperature (Kelvin)	Allen-Bradley (100 Ohm) (Ohm)	Allen-Bradley (270 Ohm) (Ohm)	Rhodium-Iron (Ohm)
500			51.4
475			48.2
425			42.8
373			37.5
323			32.2
300	100	270	29.8
280	100.5	273	27.8
260	101	276	25.7
240	102	280	23.74
220	103	285	21.73
200	104	290	19.69
190	104.5	293	18.67
180	105	296	7.66
170	106	299	16.64
160	107	304	15.87
150	108	309	14.53
140	109	314	13.46
130	110	320	12.37
120	112	326	11.38
110	114	334	10.24
100	116	343	9.2
95	117	348	8.7
90	118	354	8.18
85	120	360	7.68
80	122	367	7.19
75	124	375	6.72
70	126	384	6.27
65	128	395	5.82
60	131	407	5.43
55	135	420	5.05
50	140	435	4.73
45	145	455	4.43
40	150	485	4.17
35	158	520	3.94
30	170	560	3.75
28	175	580	3.67
26	180	610	3.6
24	190	640	3.53
22	200	680	3.45
20	210	730	3.36
18	225	790	3.28
16	241	860	3.18
14	269	980	3.07
12	300	1120	2.95
10	350	1350	2.81
9	390	1510	2.73
8	440	1770	2.65
7	520	2170	2.56
6	625	2700	2.45
5.5	700	3100	2.4
4.5	950	4500	2.28
4.2	1050	5000	2.25
4	1150	5500	2.22
3.75	1300	6200	2.19
3.5	1500	7100	2.16
3.25	1700	8400
3	2100	10000
2.8	2400	12300
2.6	2950	15000
2.4	3500	19500
2.2	4400	25500
2	5650	35000
1.9	6800	41000
1.8	8000	49000
1.7	10000	60000
1.6	12400	83000
1.55	14000	100000

Approximate % error due to magnetic fields:

Allen Bradley Resistors:

Field	8 T	14 T
2K	1.5	4
4.2K	3	6
77K	0.5	1.5

Rhodium-Iron Resistors:

Field	1 T	3 T
2K	0.14	0.88
4.2K	0.13	0.79
50K	0.14	0.84