Development of a mover havingDevelopment of a mover havingone nanometer precision and one nanometer precision and

4mm moving range4mm moving range

Y. Morita, S. YamashitaICEPP, University of Tokyo

Y. Higashi, M. Masuzawa, R. Sugahara, H. YamaokaKEK

IWAA’06, SLAC, Sep. 28, 2006

ILC (International Linear Collider)ILC (International Linear Collider)

Next generation large linear Next generation large linear acceleratoraccelerator

The beam size at the interaction The beam size at the interaction region is region is

several nmseveral nm

Motivation for the moverMotivation for the mover

The beam size is several nmThe beam size is several nm

require 1nm precision alignment1nm precision alignmentof componentsof components

Purpose of the moverPurpose of the mover

Fine tuning for the position of ILC Fine tuning for the position of ILC componentscomponents

(1nm precision)(1nm precision)

Wide range adjustment (4.5mm)Wide range adjustment (4.5mm)

SpecificationSpecification

Beam direction

V

Y

X

SpecificationSpecification

Mass: about 350kgMaterial: SUS303The load limit: about 700kg

Piezoelectric moverCam mover

This mover is for fine tuning6 piezoelectric transducersX, Y, V and x, y, v directionsMoving range: 0.4mMoving precision: 1nm

This mover is for wide range adjustment3 motorsX, V and y directionsMoving range: 4.5mmMoving precision: 0.1m

Cam moverCam mover

3 motors Shafts with offsets

motor

X

V

Top table moves in X, V and y directions

Rotation axis

Center of the thick shaft

Connecting arm

1.6mm offset

Piezoelectric moverPiezoelectric mover3 piezoelectric transducers for vertical motion3 piezoelectric transducers for horizontal motion

The table moves X, Y, V and x, y, v directions

The cross section along the line Wsprings

Cam moverCam mover

Calculation of the cam Calculation of the cam mover motionmover motion

4.5mm

1=0, 2=32 and 3 are rotated.

1=3=02 is rotated.

2mm

2mm2mm

2mm

x1r·cos1+D2y1r·sin1h2l2

(x2r·cos2D2y2r·sin2h2l2

x2r·cos3Dd2y2r·sin3h2l2

x2x12y2y124·D2

Comparison between Comparison between calculation and calculation and measurementmeasurement

Solid line: calculation result“+”marks: measurement

Pulses to the motors

Slop

e (ra

d)

Pulses to the motors

Slop

e (ra

d)

Slope of the table is compared

1=0, 2=32 and 3 are rotated.

1=3=02 is rotated.

Piezoelectric moverPiezoelectric mover

Noise of the capacitive Noise of the capacitive sensorsensor

Sampling rate is 2.54kHzSampling rate is 2.54kHz For 10 secondsFor 10 seconds Standard deviation is Standard deviation is

2.4nm2.4nm

A capacitive sensor is used A capacitive sensor is used to examine the property of to examine the property of

the piezoelectric transducersthe piezoelectric transducers

Capacitive sensor

Piezo motionPiezo motion

Piezoelectrictransducer

Capacitance typedisplacement sensor

Voltage on piezo (V)Move

men

t of

tab

le (m

)

A piezoelectric transducer has a hysteresis

Moving range is about 0.4m

Piezo resolution and response speePiezo resolution and response speedd

12nm

12nm

Resolution 1 or 2nm can be expected

Time (sec) Time (sec)

Move

men

t of

tab

le (m

)

Move

men

t of

tab

le (m

)

Response speed of the piezoelectrictransducer is 56m/sec

Vibration cancellation andVibration cancellation andnatural vibration of the natural vibration of the

movermover

stoppers

Up to 30Hz vibration cancellation system will be developed

Natural vibration of the mover is 45Hz

near

Stoppers are installed to shift the natural vibration frequency

Vibration of the table Vibration of the table (PSD)(PSD)

Vertical directionX direction

X direction Vertical direction

Red: on the tableBlue: on the floor

With stoppers

Without stoppers

30, 50, 60Hz

65Hz

50, 60Hz

over 100Hz

SummarySummary

Moving range 4.5mm + 0.4Moving range 4.5mm + 0.4mm 12nm step was clearly observed12nm step was clearly observed 1 or 2nm resolution can be expected1 or 2nm resolution can be expected Response speed of the piezo is 56Response speed of the piezo is 56m/secm/sec Natural frequency of the mover is 65Hz or hiNatural frequency of the mover is 65Hz or hi

gher with stoppersgher with stoppers

Future prospectFuture prospect

The response speed of the piezoelectric transducer is high (56m/sec)

2. Develop the vibration cancellation system up to about 30Hz (In the region>30Hz, amplitude<1nm) feedback or feedforward Michelson-Morley or Fabry-Perot laser interferometer

1. Measure again with more sensitive and stable sensors

The end of the slidesThe end of the slides

Specification

Range Resolution SpeedRough movers ±1.5 mm 0.1 m > 0.1 mm/secPrecision movers ±0.2 m 1 nm > 0.5 m/sec

Need 5 directions (X, Y, X, Y, Z)

Max. weight of load is 2 tons

Size of table (to install QD0) 600 H

- Two stage mover Rough mover stage --> Cam movers Precision mover stage --> Piezo movers

X

Y

Z

Y

Horizontal piezo actuator

Vertical piezo actuatorBeams

According to ANSYS calculation,rough mover stage is weak!--> Stopper is installed

w/o stoppers With stoppersPrimary mode 45.1 Hz 187.6 HzSecondary mode 65.5 304.5Third 148.6 635.5

Stoppers

Total system -->