Summary of KEK work for AES003

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Summary of KEK work for AES003
Ken Watanabe KEK STF Oct. 19, 2009
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Procedures for AES003
Procedure (1) Inner surface inspection for
making map of suspicious spots and scratches,
selection of grinding points (2) Application of
local grinder for selected points (3) EP 50µm
(4) Inner surface inspection for final surface
check Application of local grinder Scratches on
Iris Repair was tried only for big scratches
on welding seam, not for small scratches on side
slope. Because of many small scratches, and
used local grinder was only for flat surface, not
for slope surface. Beads on Equator Three
beads were found around 8mm away from the welding
seam. The local grinder could easily applied
to them. Diamond particle compound sheet was
used as a grinder, and water was filled between
the sheet and niobium.
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Field flatness meas _at_KEK, room temperature
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Images of Before Grinding
summary of inspection as received
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Map of the Suspicious spot in equator area AES-03
0 deg.
1-cell equator, t200 deg. Downstream Bump
0 deg.
90 deg.
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4-cell equator, t306 deg. Upstream Bump
Three bumps found outside weld area of
equators. Many scratches found on all iris parts.
5-cell equator, t187 deg. Upstream Bump
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Z-axis
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Distribution of Scratches at iris part
Scratch only big scratch
Suspicious Spot
Input coupler Side
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Example The scratches of the iris parts
1-2i, t106 deg.
1-2i, t249 deg.
1mm
1mm
1mm
1-2i, t267 deg.
5-6i, t072 deg.
1mm
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1-cell equator, t200 degree
30
93
Plotted line Z-axis
170
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4-cell equator, t306 degree
102
Plotted line Z-axis
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5-cell equator, t187 degree
100
Plotted line Z-axis
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Images of After Grinding
grinding process grinding -gt wipe off by paper
-gt camera inspection -gt additional grinding
(Repeat, if necessary)
Then, rinse out by UPW for whole cavity, camera
inspection, before EP.
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The location of target for Grinding
Equator three places (1-cell t200, 4-cell
t306, 5-cell t187)
Iris 20 places (Many scratches .. )
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Calibration of the location of Grinder head for
Equator
CCD camera
Good fit for Bump location
Height of head 13 mm
cone shape of grinding head will fit to cavity
slope
Equator
grinder structure does not touch to the
surface. Applied voltage of motor was DC18V.
Diamond sheet 1000 was used. It was enough
effective to grind beads and big scratches.
Bump location
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1-cell equator, t200 degree
Before Grinding
1st Grinding, 1000, 18 V, 5min
2nd Grinding, 1000, 18 V, 10min
3rd Grinding, 1000, 18 V, 10min
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4-cell equator, t306 degree
Before Grinding
1st Grinding, 1000, 18 V, 10min
USB camera at Grinder head
2nd Grinding, 1000, 18 V, 20min
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5-cell equator, t187 degree
1st Grinding, 1000, 18 V, 10min
Before Grinding
2nd Grinding, 1000, 18 V, 7min
USB camera at Grinder head
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Example 1-2iris t106deg.
After Grinding
Before Grinding
Before Grinding
After Grinding EP-50um
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After EP-50µm
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AES03 2009/10/09 EP target 50 µm Surface area
of cavity 9000 cm2 Surface area for removal
5400 cm2 Target of average current value 270
A Flow rate15 litter / min RPM of cavity 1
rpm room temperature 25?
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EP
FM20 2 degreaser filling
1-cell
9-cell
Ultra-sonic with degreaser filling
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????????
Brawn stains
ugly
dark
faint
AES003 EP-50µm Pure Water rinse (13 litter
/min) 600sec -gt 5sec 40sec -gt 5sec
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1-cell equator, t200 deg.
Before Grinding
After Grinding and EP 50um
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4-cell equator, t306 deg.
Before Grinding
After Grinding and EP 50um
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5-cell equator, t187 deg.
Before Grinding
After Grinding and EP 50um
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1-2iris t024deg
Before Grinding
No Grinding in this part.
EP-50um
scratches around cavity rotation direction 0 88
deg. 280 360 deg.
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1-2iris t106deg.
Before Grinding
After Grinding
After Grinding EP-50um
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4-5iris t244deg
Before Grinding
After Grinding
After Grinding EP-50um
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Summary
Surface inspection, RF inspection and surface
repair was done for AES003 during June to
October, 2009 at STF, KEK. Bumps around equator
were removed and smoothed by the combination of
local grinding and EP. We could not measure the
gradient performance in STF because of full
schedule of S1G cavity measurement. Only the
big scratches (19 scratches) on iris were done
local grinding. We did not apply local grinding
for the other small scratches on iris. (Only EP
was applied to them.) After EP 50µm treatment,
degreaser rinse, UPW rinse and HPR, surface
inspection were done. Then HPR was applied again,
and then sealed, pumped and then packed into
wooden box for transporting back to FNAL.
Oct 26, 2009 AES003 left KEK Oct 29, 2009 left
Narita