| Lines 2-35 were replaced by lines 2-63 |
| - partly by PSI, Risø, MaNEP and SNF. 14.9 Tesla is the maximum |
| - field achievable with nowadays technology for a split pair coil (which |
| - is needed for wide angle access). This limit could in principle be |
| - increased to 17.5 by means of a dysprosium insert for small samples. |
| - This option is not (yet) available at SINQ. |
| - |
| - !Specifications |
| - |
| - |field at sample |14.9 Tesla |
| - | " without lambda stage|13.5 Tesla |
| - |diameter of sample space|20 mm |
| - |max. useable sample height|20 mm |
| - |split access angle|+- 2 deg |
| - |sample height for +-2 deg access(visible by neutrons) |14 mm |
| - |horizontal access angle|> 330 deg |
| - |homogeneity over a 10 mm diameter sphere|0.5% |
| - |distance from base of cryostat\\to scattering plane|240 mm |
| - |operating current for 14.9 T|120 A |
| - |maximum allowed vertical and horiontal magnetic forces|1000 N |
| - |total weight including cryogens|650+-30 kg |
| - |field stability in persistent mode|0.01 % / hour |
| - |total radial aluminium window thickness|43.4 mm |
| - |total radial aluminium in entrance window|8.6 mm |
| - |entrance window size (radiussed corners 3 mm)|15 x 15 mm |
| - |useable LHe capacity|55 l |
| - |LHe boil off (static mode)|<350 cc/hr |
| - |LN2 capacity|60 l |
| - |typical LN2 boil off|600 cc/hr |
| - |diameter for transfer tube|12 mm |
| - |temperature range (no field dependend limitations)|1.6 ... 300 K |
| - |temperature stability|+- 0.1 K |
| - |automatic needle valve control only above|3 K |
| - |exchange gas needed in sample space (measured at RT)|<15 mbar |
| - |sample space diameter above magnet|49.5 mm |
| + partly by |
| + * [PSI|http://www.psi.ch] |
| + * the [Carlsberg Foundation|http://www.carlsbergfondet.dk/] |
| + and the Danish National Science Foundation (danish: [FNU|http://www.forsk.dk]) |
| + * [MaNEP|http://www.manep.ch] |
| + * [SNF|http://www.snf.ch] |
| + |
| + [ma15d.jpg] |
| + |
| + 14.9 Tesla is the maximum field achievable with nowadays technology |
| + for a split pair coil (which is needed for wide angle access). This |
| + limit could in principle be increased to 17.5 by means of a dysprosium |
| + insert for small samples. This option is not (yet) available at SINQ. |
| + |
| + A rotatable sample stick has been made at PSI using a similar design at the |
| + ILL. This allows to leave the magnet in a fixed omega position and to |
| + turn the sample orientation within the magnet. |
| + |
| + !Restrictions |
| + |
| + __after several quenches, operation above 12.5 without lambda stage is not recommended [see|http://samenv:8080/sample_environment/61]__ |
| + |
| + Due to force limits, restrictions are defined for the use of MA15. |
| + ||Instrument ||Allowed Max. Field [[Tesla] |
| + |RITA-2 |11.5 ... 14.9, see [MA15 Rita Restrictions] |
| + |TASP |14.9, see [MA15 TASP Restrictions] |
| + |EIGER |13, see [MA15 Eiger Restrictions] |
| + |ZEBRA |14.9 for the longer distance as defined for MA15 |
| + On all other instruments, MA15 can not yet be used. |
| + |
| + [Specifications / Ramp Limits|MA15Specifications] |
| + |
| + More information on intranet page (Drawing): [LdmWiki:MA15] |
| + |
| + [Omega Motor Change on Rita2] |
| + |
| + [Cooldown Procedure|MA15Cooldown] |
| + |
| + !Pending Issues |
| + |
| + * The automatic needle valve does not always work properly. |
| + A mechanical problem was solved by Oxford Instruments. |
| + It is still a problem that sometimes the needle valve bar |
| + gets frozen. This problem might be avoided when keeping warm |
| + the top of the needle valve during fill. However, at high |
| + fields, the air dryer might not work! |
| + |
| + * The nitrogen level gauge does not work. This has to be fixed, but |
| + it seems that it may appear often. |
| + |
| + * During He-fill, LN2 has to be filled again in order to avoid |
| + air sucking into the LN2 dewar. |
| + |
| + * In order to be used possibly on other instruments, the instruments have to be |
| + checked for magnetic materials around the sample table. After some force |
| + tests, and after eventual modifications of the instrument, the conditions |
| + for a safe operations have to be defined. The next candidate for these |
| + tests is TASP. |
| + |
| + [ma15b.jpg] |
| + [ma15a.jpg] |
| + [ma15c.jpg] |
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