M321/M331 Mirror Switchyard Design Review

23
Engineering Division M321/M331 Mirror Switchyard Design Review Tom Miller 11-29-2006

description

M321/M331 Mirror Switchyard Design Review. Tom Miller 11-29-2006. Basic layout of M321/M331 mirror switchyard. y. y. z. z. x. x. M321. M321. M331. M331. Figure 4: Coordinate system of mirror switchyard. Figure 4: Coordinate system of mirror switchyard. - PowerPoint PPT Presentation

Transcript of M321/M331 Mirror Switchyard Design Review

Page 1: M321/M331 Mirror Switchyard Design Review

Engineering Division1

M321/M331 Mirror Switchyard Design Review

Tom Miller11-29-2006

Page 2: M321/M331 Mirror Switchyard Design Review

Engineering Division2

Basic layout of M321/M331 mirror switchyard

Page 3: M321/M331 Mirror Switchyard Design Review

Engineering Division3

x

y z

M321

M331

Figure 4: Coordinate system of mirror switchyard

Alignment / stability tolerance and mechanical steps for M321 and M331

DimensionAlignment tolerance Mechanical step Stability tolerance

X 100m 38m 19m

Y 1mm N/A 0.5mm

Z 300m N/A 150m

x 1o N/A 0.5o

y 1mrad 30rad 15rad

z 24rad N/A 12rad

x

y z

M321

M331

Figure 4: Coordinate system of mirror switchyard

Alignment, resolution and stability requirements

(Roll)(Pitch

)

(Yaw)

Page 4: M321/M331 Mirror Switchyard Design Review

Engineering Division4

Basic Optic Design

Single optic for M321 and M331 with diagnostic pass – through. Mounting details are omitted

One optic versus twoSingle optic advantages:•No mechanisms for alignment between M321 & M331•Lighter and more rigid optic and mounting for better stability•Smaller required translation due to compact design•Faster setup and commissioning due to fixed angle between M321 & M331

Single optic disadvantages: •Up-front cost of the optic. This can be offset by reduced mechanism and setup costs if optics are not routinely damaged•Manufacturing tolerances on the relationship between the two optical surfaces must be good for quick replacement of the optic.

Page 5: M321/M331 Mirror Switchyard Design Review

Engineering Division5

Maximum Required Motions

Translations(x):(Single optic)RIXS Rotated: 12.01mm outboundARPES Rotated: 17.97mm inboundTotal: 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

Page 6: M321/M331 Mirror Switchyard Design Review

Engineering Division6

Mechanism Fundamentals

Initial concept: Mount the optic(s) rigidly in the chamber and translate the chamber with a single

slide and pitch and roll with struts to steer the beam.

Advantage: • Familiar approach• Easy installation survey. The optic(s) can be accurately fiducialized in a lab

and those numbers used for installation alignment.

Disadvantages:• Input and output bellows are required. Large and variable off-axis forces act

on the translation slide and rotation mechanisms• If pumping is added to the chamber, the pump must move with the chamber

or be bellows isolated. This will result in a large mass offset from the slide or more non-constant bellows forces. Both solutions result in poorly placed variable forces.

• Pitch and roll motions intrinsically couple to all other motions.• Parasitic motions from variable off-axis forces may make high resolution

encoder readings meaningless

Page 7: M321/M331 Mirror Switchyard Design Review

Engineering Division7

Mechanism FundamentalsNew concept: Mount the chamber rigidly and move the optic(s)

Advantages: • Bellows forces are small and self-cancelling • Pitch corrections are nominally independent of roll• Translations are nominally independent of pitch and roll• Any force required for translation is small and almost directly in line with

the linear bearings in the stages.• All sources of backlash in the mechanism are spring loaded in the axis of

freeplay. • Pitch and roll are flexure-based motions and therefore very repeatable• Large pumps can be mounted beneath the tank with no effects on motion. • Small off-axis forces will make encoder readings more meaningful• The moving masses are small and the mechanisms optimized for stiffness.

The vibrational modes of the mechanism are thus above 200Hz.• All mechanism parts are stainless steel or cast iron. This should yield good

thermal stability.

Page 8: M321/M331 Mirror Switchyard Design Review

Engineering Division8

Mechanism Fundamentals

New concept: Mount the chamber rigidly and move the optic(s)

Disadvantages:• Unfamiliar design• 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.

• Installation surveys of the optic will be relatively imprecise. The orientation of the optic to outside fiducials must be determined after the optic is mounted in the tank. The in-vacuum fiducials are close together and difficult to survey in the tank.

Page 9: M321/M331 Mirror Switchyard Design Review

Engineering Division9

Mechanism Overview

Page 10: M321/M331 Mirror Switchyard Design Review

Engineering Division10

Translation Mechanism

Page 11: M321/M331 Mirror Switchyard Design Review

Engineering Division11

Chamber pass-through

Page 12: M321/M331 Mirror Switchyard Design Review

Engineering Division12

Roll Mechanism

Page 13: M321/M331 Mirror Switchyard Design Review

Engineering Division13

Pitch Mechanism

Page 14: M321/M331 Mirror Switchyard Design Review

Engineering Division14

Mirror details

Page 15: M321/M331 Mirror Switchyard Design Review

Engineering Division15

Center Section

Page 16: M321/M331 Mirror Switchyard Design Review

Engineering Division16

Pitch Hinge Details

Page 17: M321/M331 Mirror Switchyard Design Review

Engineering Division17

Micro-e Encoder Scale

Page 18: M321/M331 Mirror Switchyard Design Review

Engineering Division18

Center Section Mounting

Page 19: M321/M331 Mirror Switchyard Design Review

Engineering Division19

Pitch Mechanism First mode

Page 20: M321/M331 Mirror Switchyard Design Review

Engineering Division20

Spring stress at 1mRad pitch

Page 21: M321/M331 Mirror Switchyard Design Review

Engineering Division21

Demagnification spring deflection with 1mRad pitch

Page 22: M321/M331 Mirror Switchyard Design Review

Engineering Division22

Roll Mechanism first mode

Page 23: M321/M331 Mirror Switchyard Design Review

Engineering Division23

Cost estimate

Fab and purchases: $78,000Assembly (200hrs) : $20,000

Total: $100k