M321/M331 Mirror Switchyard Design Review

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M321/M331 Mirror Switchyard Design Review
Tom Miller 4-5-2007
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Basic layout of M321/M331 mirror switchyard
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Alignment, resolution and stability requirements
Alignment / stability tolerance and mechanical
steps for M321 and M331
Dimension Alignment tolerance Mechanical step Stability tolerance
X 100mm 38mm 19mm
Y 1mm N/A 0.5mm
Z 300mm N/A 150mm
Qx 1o N/A 0.5o
Qy 1mrad 30mrad 15mrad
Qz 24mrad N/A 12mrad
(Yaw)
(Pitch)
(Roll)
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Maximum Required Motions

• Translations (x)
• (Single optic)
• RIXS Rotated 12.01mm outbound
• ARPES Rotated 17.97mm inbound
• Total 29.98mm (nominal)
• Pitch (Thetay )
• (Single or dual optics, RIXS ARPES)
• High Res grating /-259 microradians
• High Flux grating /-168 microradians
• Roll (Thetaz )
• (Single or dual optics, RIXS ARPES)
• /- 5 milliradians

RIXS rotated
ARPES rotated
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Mechanism Fundamentals

• Parasitic motions
• Roll couples to pitch and translation. 1
  milliradian of roll induces 200 microradians of
  pitch for ARPES, 100 microradians of pitch for
  RIXS and 0.13 microns of translation. Intrinsic
  roll errors should be very small, and thus the
  roll corrections should also be small, so pitch
  coupling should not be a problem. Translation
  coupling will be insignificant.
• Pitch couples to translation. 250 microradians of
  pitch results in 9 microns of translation at the
  nominal reflection point. The large pitch changes
  required for grating selection also have an
  associated 1.5mm translation, so this number is
  acceptable.
• Survey issues
• Installation surveys of the optic will be
  relatively easy to do, as the optic can be very
  well related to the fiducials on the translation
  mechanism. Since the pitch mechanism only pulls
  (positive pitch,) the flange and chamber should
  be installed at -1mrad to -2mrad in pitch
  initially.

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Mechanism Overview
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Translation Mechanism
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Proposed Probe Support

• Im not convinced this is a good idea, but it is
  possible.

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Roll Mechanism
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Pitch Mechanism
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Chamber
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Mirror details
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Center Section
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Pitch Hinge Details
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Micro-e Encoder Scale
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Center Section Mounting
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Pitch Mechanism First mode
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Spring stress at 4mRad pitch
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Demagnification spring deflection with 4mRad
pitch
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Translation Mechanism first mode
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Pumping and Support Details
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Cost estimate

• Fab and purchases 78,000
• Assembly (200hrs) 20,000
• Total 100k