Small beam - Post Vert A mirror

Post Vertical mirror coordinates (Branch A) for small beam sizes

March 2022, by Igor Pis

Grating	Z (d ± 0.2 mm)	Z (No. Screw revolutions)	Pitch (μm) See Note 2	Comment
"Large beam"	< 55 mm	2 to 4 CCW from "0" pos		See Note 3
SG2, SG3, SG1 standard position	51 mm	2 CCW from "0" pos	-8500	Standard position from Aug 2022
SG2, SG3, SG1	55.1 mm	"0"	(-7150) -8099 (-0.5)	The Pitch values changed in July 2022
SG2, SG3 small beam	59.2 mm	2 CW from "0" pos.	-6350
SG4 standard	61.1 mm	3 CW from "0" pos	-6050
SG1 small beam (ARPES)	69.2 mm	7 CW from "0" pos	-5200	See Note 1

Note 1: To have enough space for moving the mirror down, the top cover of the optical bench under the pneumatic valve of the mirror chamber must be removed.
Note 2: The Pitch values are approxiamte, they should be veryfied for XPS/ARPES every time the Z position is changed.
Note 3: When Z is moved up (d below 55 mm), the beam is broadening in vertical direction, the XPS signal increases, but the resolution decreases (not very much for SG2, but it can quite a lot for SG3 at high photon energies and for SG4 at all energies. The resolution(Au4f peak width) should be checked when the Z is moved here.