Table 3. Alignment tolerance, precision and range of mechanical motion.

Note that we adopt the SHADOW convention for the coordinates: on the optical surface, X is transverse to the beam path, Y is along the beam path, and Z is normal to the optical surface.

	Alignment tolerance	Mechanical motion (step resolution; range)
Spherical mirror
MX (transverse)	±25 µm	N/A
MY (along beam path)	±25 µm	N/A
MZ (up/down)	±5 µm	N/A
MΘX (pitch)	±0.01°	0.0001°/step; 2°
MΘY (roll)	±0.01°	N/A
MΘZ (yaw)	±0.1°	N/A
VLS plane grating
GX (transverse)	N/A	10 µm/step; 40 mm
GY (along beam path)	±50 µm	N/A
GZ (up/down)	±10 µm	N/A
GΘX (pitch)	N/A	0.0001°/step; 5°
GΘY (roll)	±0.01°	N/A
GΘZ (yaw)	±0.1°	N/A
Spectrometer
SX (transverse)	±100 µm	N/A
SY (along the beam)	±100 µm	N/A
SZ (up/down)	±10 µm	N/A (or source vertical move)
Detector
DY (along the beam)	N/A	1 µm/step; 150 mm
Wolter mirrors WM1
WM1X	100 µm	N/A
WM1Y	±5 µm	0.5 µm/step; 1 mm
WM1Z	±2 µm	0.2 µm/step; 100 µm
WM1ΘX	±0.001°	0.0001°/step; 0.1°
WM1ΘY	±0.01°	N/A
WM1ΘZ	±0.01°	N/A
Wolter mirrors WM2
WM2X	100 µm	N/A
WM2Y	±10 µm	0.5 µm/step; 1 mm
WM2Z	±2 µm	0.2 µm/step; 100 µm
WM2ΘX	±0.001°	0.0001°/step; 0.1°
WM2ΘY	±0.005°	N/A
WM2ΘZ	±0.01°	N/A