Restrictions for MA7
max.Force
horizontal  500N 
vertical  1000N 
Summary
Instrument  Allowed maximum field [Tesla]  Conditions 
AMOR  4  field perpendicular beam 
AMOR  6.8  field parallel beam 
RITAII  4 ... 6.8  see below 
SANSI  6.8 / 6.2 (full field)  with spin flipper only when field perpendicular to beam 
SANSII  6.8 / 6.2 (full field)  
TASP  6.8  see below (A3 does not move > 4 Tesla) 
EIGER  6.8 / 6.2 (full field)  goniometer removed 
ZEBRA  6.8 / 6.2 (full field)  L1 = 1500 mm, L2 = 785 mm (1D detector) 
ZEBRA  5 / 5  L1 = 1000 mm, L2 = 785 mm (1D detector) 
Restrictions on RITAII
Goniometer removed.
Provisional force measuremnents on RITAII have shown that
the operation of MA7 on RitaII is allowed:
 between 3.0 and 18.0 meV (a2 >= 37 deg) at a distance of 450 mm or more, up to 4 Tesla
 between 3.0 and 8.0 meV (a2 >= 56 deg) at a distance of 450 mm or more, up to 4.4 Tesla
 between 3.0 and 8.0 meV (a2 >= 56 deg) at a distance of 540 mm or more, up to 5.5 Tesla (we had a quench at 6 Tesla!)
 between 3.0 and 13.68 meV (a2 >= 42.7 deg) at a distance of 680 mm* or more, up to 6.8 Tesla
* at a distance of more than 680 mm or a2 angles < 42.7 the analyser tank touches the wall at a4 ~= 45
For any other configuration force tests have to be redone.
MA7 Original Data
How the distance has to be measured.
In this example the distance is around 400 mm.
Restrictions on AMOR
Provisional force measuremnents on AMOR have shown that
the operation of MA7 on AMOR is allowed with a field perpendicular
to the beam at least up to 4 Tesla.
The distance to the shielding wall between AMOR and SANSII has
to be at least 540 mm, measured from the aluminium window
(or about 870 mm to the magnet centre).
Torque Calculations
In general, the forces are not only radial, but also tangential,
inducing a torque onto the magnet. For estimating the forces
on the fixation, we need to take into account the distance of
the fixation points from the coil center.
For MA7, with a mean coil radius of about 100 m and fixation points
at about 150 mm for the coil center, we get the following:
Ro: object distance (mm)
phi: angle (deg) between field direction and direction of object, for maximum force on fixation
Fp: force when object on magnet axis (in field direction)
Ft: maximum total force on fixation
Ro  phi  Ft / Fp 
<600  0  1.0 
800  20  1.04 
1000  27  1.13 
1200  32  1.25 
For the distance to the shielding wall we have to add 1/5 of the edge
distance for the mean distance of the material that has to be taken
into account (870 * 6/5 = 1044 mm).
Measured force at 3.4 Tesla: 180 N.
Extrapolated to 5 Tesla: 390 N.
Factor 1.2 for including torque: 470 N.
With a reasonable security margin, we allow to go up to 4 Tesla.
Restrictions on TASP
Goniometer removed.
Beryllium Filter Distance 27 cm (see photo)
Sample table  Monochromator  73 cm
A2  a4  Allowed field 
92 < A2 < 41 (Ei=14.7 meV)  <= 119  6.8 Tesla 
WARNING: Motor A3 may not move with a field > 4 Tesla
This data is derived from the force test 7. July 2015:
4.8 Tesla, horizontal force 150 N (towards Beryllium filter), vertical force 180 N.
Restrictions on SANS
Allowed up to maximum field independend of the field direction.
With spin flipper only when field perpendicualr to beam and in asymmetric mode.
Other configurations with spin flipper have to evaluated.
Force measurements (without spin flipper):
field direction  field  horizontal force  vertical force 
parallel to beam  4.9 Tesla  80 N  340 N 
perpendicular to beam  4.9 Tesla  110 N  180 N 
Force Test on SANSII 21.5.2015
4.9 T perpendicular to beam  300 N vertical  140 N horizontal 
4.9 T parallel to beam  300 N vertical  60 N horizontal 
Attachments:
distanceTASP.jpg
taspFilterMA7.png
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This page last changed on 18Sep2020 09:35:18 UTC by MarkusZolliker.
