Quadrant Fabrication Study

KEK

Toshikazu TAKATOMI

Yuichi WATANABE

2nd Collaboration Meeting on X-band Accelerator Structure Design and Test-Program13-15 May 2008

Test Quadrant Structure This structure is made for four parts. The cell size is individually different for accelerating gradient. It needs the milling for three-dimensional shape. Theoretically exact profile tolerance is under 5 μ ｍ . Material is Zr-Cu(C150). The nominal dimensions 　 are not visible on the drawing, So

We must extract from 3D model. All edges of reference surfaces zone A and B have a radius

of 0.05±0.01mm. Don’t have the burrs.

The drawing of test Quadrant Structure

Reference surface Flatness ： under 5μ ｍ Square ness ：　 under 5μ ｍ

Cavity （ Zone A ） Theoretically exact profile tolerance ：　 5 μ ｍ Surface roughness ： Ra0.1

Beam Coupler Cavity Coupler

Issues in processing

To keep in straight The bending must be under 5μm for needs straight of beam line. Material is Zr-Cu(C150:φ65×300). It can't have heat anneal.We have to get the processing which doesn't bend.

Dimension and theoretically exact profile need high precision Error factor is variations in temperature and in machine motion.

We have to study for error factor.

Quality of Surface roughness We have to get under Ra0.1 in surface roughness. but, it gets difficult at

ball-nosed end mills.

We have to study for the processing.

Points of Fabrication

Fabrication was the 5-axis precision machine that is controlled with constant temperature at 23±0.5 ℃degrees.

CAM data was made to change in 23 degrees ℃temperature.

We studied to find the best processing.

Alignment of the machine and shape of the tools was measured to keep high precision.

It is processed four times to repair bend.

Flatness measurement of referencesReference surface A

-0.010

-0.005

0.000

0.005

0.010

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31

point No.

diffe

renc

e(μm

)

ABCD

Reference Ａ

Measurement point

Reference surface got at under 6 μ ｍ .(under 4 μ ｍ　 at cavity)Reference B

Reference surface B

-0.010

-0.005

0.000

0.005

0.010

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31

point No.

diff

ere

nce

(μm

)ABCD

D C B A A B C D

123

4

5

6n

Non fixation

Non fixation

Cavity

Cavity

Dimensions of Beam Direction

It had Inclination about 0.02mm Each distance was ±0.005mm

CT ： Disk thicknessCW ： Cell width

Dimensions(Cell　to　DIM-C)meas.- design（ ）

y　=　0.0008x　- 　0.0085- 0.03

- 0.02

- 0.01

0.00

0.01

0.02

0.03

0 2 4 6 8 10 12 14 16 18 20

Cell　No.

Difference(mm)

CL- INCL- OUT

　(CL- OUT)線形

Dimension(Cell　and　Disk)(meas.- design)

- 0.03

- 0.02

- 0.01

0.00

0.01

0.02

0.03

0 2 4 6 8 10 12 14 16 18 20

Cell　No.

Difference(mm)

CT

CW

Dimensions of depth data (Cell and Iris)

Each distance was -0.01mm±0.004mm

Depfh(Cell ris)、Ｉmeas.- design（ ）

- 0.03

- 0.02

- 0.01

0.00

0.01

0.02

0.03

0 2 4 6 8 10 12 14 16 18 20

Cell　No.

Difference(mm)

Dep- 2aDep- 2b

Iris

Ce

lls

Profile measurement (Beam direction)

65 70 75 80

-9

-8

-7

-6

-5

-4

-3

Beam direction No. 18cells

Tolerance is ±2.5μm.Best fit result

It was almost within the tolerance.

Profile measurement (cross direction)

-15 -10 -5 0 5 10 15

-18

-16

-14

-12

-10

Cross direction of No.18cell

Cross direction of No.18iris

-10 0 10 20

-20

-15

-10

-5

0

It’s OK!

It had error about 5μm.

Tolerance is ±2.5μm.Best fit result

Tolerance is ±2.5μm.Best fit result

Surface roughness

Roughness in cavity was under Ra0.4

A-1 ：　Ra0.20A-2 ：　Ra0.17B-1 ：　Ra0.20B-2 ：　Ra0.33C-1 ：　Ra0.11C-2 ：　Ra0.13D-1 ：　Ra0.15D-2 ：　Ra0.16

1

2

1

2

1

2

1

2

A

B

C

D

It is limited by our process now??

Tool speed have to move very slowly to get high quality by ball-nosed end mills.but, it have very long process times. then ,it occur of another error factor.

Inspection of edgesSide A

input output

Iris_0-1_sideA Iris_11-12_sideA Iris_18-19_sideAIris_5-6_sideA

Burr was not seen.It had edges of chamfering at 0.05mm. This is good!

Summary Reference surface got at under 6 μ ｍ . Cavity was under 4 μ ｍ . Dimensions of beam direction had inclination about 0.02mm. It

was gotten variations in temperature.

We had to study. Profile measurement at beam direction was almost in the

tolerance. Roughness in cavity was under Ra0.4

In the future, we will reach the goal based on those results.

AcknowledgmentWe would like to express my gratitude to U-CORPORATION Co.,Ltd and Hitachi,Ltd about fabrication study.