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The new Synchrotron Optomechanics at BESSY

Tino NollBESSY GmbH

Albert-Einstein-Strasse 15, D-12489 Berlinnoll@bessy.de

A Typical Beamline Layout

storage ring

u n d u la to r

premirror

refocusing mirror

monochromator

mirror

entrance slit

exit slit

experimentdetector

e-

control of experiment

data recording

control of monochromator

sample

e

e

e-

e-

diffractiongrating

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2

Electron Storage Ring with Beamlines

premirror

refocussing mirrorexperiment

monochromator

storage ring

3

Beamlines

4

SMU

Dip-M1

3

insertion device

premirror

aperturemirror

grating

mirror

aperture

experimentdipole magnet

l4

l2

l3

l1

ca 17 m

ca 16 bis 30 m

• Degree of freedom?

• Stroke?

• Step resolution?

• Acceptable error motions?

• Acceptable modes of vibrations?

mfe μ3...1≈

ξΔ⋅⎟⎠

⎞⎜⎝

⎛= ∑=

sin1

n

aae lf

Requirements of Accuracy of Movement of a Mirror (SMU)

moving direction stroke reproducibility resolution

rotation X 2,4 mrad 10 nrad 10 nrad

translation X 2 mm 1 µm 0.06 µm

rotation Y 4.3 mrad 50 µrad 0,3 µrad

translation Y 50 mm 5 µm 1.5 µm

rotation Z 9 mrad 25 µrad 0,3 µrad

translation Z - - -

x

zy

4

Kinematic Couplings

Reproducibility: linear 1μm, angular ?

7ll1

Δ Δ1

α

l

8

5

Random Error Motions

α

ms μ3...1≈Δ

mddd μ121 ≈−=Δ

),( sdf ΔΔ

d2

d1

error of straightnessdriving error

error of straightness

yaw

roll

One Motion and five Error Motions

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Accuracy of Commercial Linear Roller Bearings

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Stacks of Singel Axis Stages

advantages• modular

• large stroke

disadvantages

• sequential combination

• friction

• limit of accuracy 1μm

• random error motions

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8

Hexapod

advantages

• DOF 6

• high stiffness

• low mass

disadvantages

• six motor drives are always

necessary

• no intuitively manually movable

• lost of accuracy of the single axes

potential of improvements

• Cartesian strut topology

• play free joints

• drives

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Parallelogram

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Rotational Pattern of Double Joined Struts

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10

Segments of a Rotational Strut Pattern

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Parallelogram Stage

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Trapezoid Stage

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Strut Sxx

yx zStrut Sz

Strut Sy

Combination of a Parallelogram with a Trapezoid

DOF 3

Translation in Z-Direction

xy

z

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Translation in Y-Direction

x y z

Rotation around X

x y z

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25

X

Y

Z

SZ

SXX

SYY

SY SZZ

SX

Spatial Topology DOF=6

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Rotation around X

X

Y

Z

SZ

SXX

SYY

SY SZZ

SX

Rotation around Y

X

Y

Z

SZ

SXX

SYY

SY

SZZ

SX

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Rotation around Z

X

Y

Z

SZ

SXX

SYY

SY SZZ

SX

Translation in X-Direction

X

Y

Z

SZ

SXX

SYY

SY SZZ

SX

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Translation in Y-Direction

X

Y

Z

SZ

SXX

SYY

SY SZZ

SX

Translation in Z-Direction

X

Y

Z

SZ

SXX

SYY

SY SZZ

SX

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36

19

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Undulator

Dipole Magnet

Dipole Beam

Monochromator A

Refocussing Mirror A

Experiment A Experiment B

Refocussing Mirror B

Monochromator B

Switching Mirror Unit

Undulator-Beam

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zwei Drehungen um Achsen, die in der Spiegeloberfläche liegen

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