nELBE target control (Obsolete! Has to be updated!)
The target for neutron scattering experiments is mounted in the centre of the BaF2-Array. For this purpose a target holder with two useable positions is available. This target holder can be moved via a stepping motor.
The remote control for this stepping motor can be done by means of a simple switch-key that can be found in room 250 of the ELBE building or via software using MBS. For the latter the setup values "movetarget", "settarget" and "changetargetauto" can be used (see VME initialization).
The stepping motor can set the target holder to 5 different positions relative to the incoming neutron beam. These are shown in Table 2 and 3 below. Position 0 is the reset position of the stepping motor.
The current position can be read from the LED interface of the black box containing the stepping motor control. This box can be seen from the USB camera connected to the HV control PC (FWK46) placed in room 125.
The sequence in which the position is changed is controlled via two dip switches accessible on top of the black box. The available sequences are shown in Table 1.
Table 2: Positions of the double target holder
|Position 0:||Position 1:||Position 2:||Position 3:||Position 4:|
Table 3: Positions of the target holder
|Position 0:||not used|
|Position 1:||Fe-nat (99.8%): diam. = 20 mm, l =8.0 mm, m = 19.81809 g + Polyester: 0.012 mm, m = 0.09671 g|
|Position 2:||not used|
|Position 4:||not used|
The following Targets are available:
|Fe-nat (+ Polyester)||52 mm||2.5 mm (+ 0.012 mm)||41.60528 g (+ 0.09671 g)|
|Fe-56 (+ Polyester)||20 mm||(+ 0.012 mm)||1.99418 g (+ 0.02602 g)|
|Fe-nat 99.8% (+Polyester)||20 mm||8.0 mm (+ 0.012 mm)||19.81809 g|
|Fe-nat 99.8%||20 mm||8.0 mm||19.8205 g|
|Fe-nat 99.8%||70 mm||8.0 mm||242.5651 g|
|Fe-nat (ARMCO Weicheisen)||79 mm||4.5 mm||172.1030 g|
|Fe-nat (ARMCO Weicheisen)||79 mm||3.1 mm||119.6885 g|
|Na-nat (+Polyester)||33.2 mm||17.1 mm (+ ? mm)||13.4084 g|
|Zr-nat (ZrO2)||79 mm||4.5 mm||133.7881 g|
Other material available can be found here.