I am trying to set up a KB mirror system, but the focal position does not match the expected design value.
According to the mirror design, both the HFM and VFM are elliptical mirrors with the same curvature.
Therefore, I would expect the focal position to be located at the same distance.
Since the design values of p+q of M1 & M2 are equal, I do not understand why the focal positions are different.
The elliptical mirror parameters are shown in the figure below, where p and q correspond to f1 and f2.
However, when I trace each mirror separately in XRT, I obtain different focal positions:
HFM focuses at approximately (p + q - 18 mm)
VFM focuses at approximately (p + q - 5.5 mm)
beamLine.HFM = roes.EllipticalMirrorParam(
bl=beamLine,
name=None,
center=[r"auto", 172.9, r"auto"],
pitch=0.13,
roll=1.57079,
limPhysX=[-10.0, 10.0],
limPhysY=[-75.0, 75.0],
p=M1p,
q=M1q,
isCylindrical=True,
isClosed=True,
alarmLevel=0)
beamLine.VFM = roes.EllipticalMirrorParam(
bl=beamLine,
name=None,
center=[r"auto", 301.6, r"auto"],
pitch=0.125,
roll=3.14159,
yaw=-0.26,
limPhysX=[-10.0, 10.0],
limPhysY=[-50.0, 50.0],
p=M2p,
q=M2q,
isCylindrical=True,
isClosed=True,
alarmLevel=0)
From the above M1p + M1q = M2p + M2q
I am trying to set up a KB mirror system, but the focal position does not match the expected design value.
According to the mirror design, both the HFM and VFM are elliptical mirrors with the same curvature.
Therefore, I would expect the focal position to be located at the same distance.
Since the design values of p+q of M1 & M2 are equal, I do not understand why the focal positions are different.
The elliptical mirror parameters are shown in the figure below, where p and q correspond to f1 and f2.
However, when I trace each mirror separately in XRT, I obtain different focal positions:
HFM focuses at approximately (p + q - 18 mm)
VFM focuses at approximately (p + q - 5.5 mm)
From the above M1p + M1q = M2p + M2q