Specification for goniometer mount for radiators
The planned Hall-D goniometer is a 6-axis device with 3 translational and 3 rotational degrees of freedom:
Short description of the stages (from bottom to radiator mount):
- horizontal translational stage (x-stage) to move the into/out-of beam (range ~20 cm)
- vertical translational stage (y-stage) to adjust the height of the radiator (range ~5 cm)
- rotation about the vertical axis (yaw) to ±15 deg.
- rotation about the horizontal, perpendicular to the beam direction (pitch) to ±15 deg.
- craddle: rotation about the beam direction (roll) to +120 deg. and -30 deg.
- horizontal translational stage (target ladder), positioned in the center of the craddle and range of ≥ 8 cm (space for mounts of 5 diamonds and thin foil for normalization run).
The listed accuracy is based on the existing Huber goniometer in Hall B.
- accuracy of translational motion:
vertical: 200 μm horizontal (bottom axis): 200 μm target ladder (fine tuning): 25 μm
- accuracy of rotational motion:
yaw (about vert.axis): 1.5 μrad pitch (about horizontal, perp. to beam): 1.5 μrad roll (about beam direction): 3.0 μrad
End switches required for all axes, additional home switches for rotations.
The device is operated under vacuum (~10-6).