Undulator Tuning Status

1
Undulator Tuning Status

• Z. Wolf, S. Anderson, R. Colon, S. Jansson, D.
  Jensen,
• S.Kaplunenko, Y. Levashov, Ed. Reese, A.
  Weidemann

2
Undulator Tuning And Related Topics

• Overview
• Undulator quadrupoles
• Transportation test
• Temperature tests
• Repairs
• Shim-beampipe interference fix
• Re-tuning status/schedule
• Tunnel field map
• Reference undulator

3
Undulator Quadrupoles Finished
Scott Anderson (Detailed report in preparation)
No Tolerance (individual supplies)
No Tolerance
No Outliers
4
Undulator Quadrupoles Finished
Tolerance 3 microns
Absolute Value Of Magnetic Center Shift In BBA
Cycle
5
Undulator Quadrupoles Finished
Difference Between Magnetic And Mechanical Centers
6
Transportation Test
D. Kharakh, Y. Levashov, N. Horton, Y.
Levashov, E. Reese
Details in LCLS-TN-08-9
During test
Outside and undulator temperatures Undulator
temperature rise 1 F (0.6 C)
Route
7
Transportation Test
8
Transportation Test
Conclusion No significant changes occurred to the
undulator during the transportation test.
9
Temperature Tests
Y. Levashov, E. Reese
Details in LCLS-TN-08-8
Undulator Storage Tlab 20 0.1 C Building 750,
18 undulators , T 11 C, 3 checked Building 33,
6 undulators , T 27 C, 2 checked Building 81
storage, 5 undulators , T 20 2 C, 1
checked Building 81 laboratory, 1 undulator, T
20 0.1 C
Problem The undulator fiducialization
changed. Examples to follow.
10
Bldg 750 Temperature
20 C
9 C
Temperature
11 C
11
Building 750 Gap Change
Pole sub-assembly length
Field changes agree with gap changes
Gap change during storage
1 micron average gap change
CMM
Hall probe
12
Building 750 Undulator Changes
x-trajectory, y-trajectory, phase errors, all
ok But The fiducialization changed by 200
microns in x
13
Building 750, 3 Undulators
14
Building 33 Temperature
J. Chan
15
Building 33 Gap Changes
16
Building 81 Storage Area Temperature
17
Building 81 Storage, Gap Changes
18
Building 81 Lab, Gap Changes
T 20 0.1 C
19
Temperature Fiducialization Change Summary
T 20 2 C
T 20 0.1 C
Undulator 39
T 11 C
T 27 C
err 50 µm
err 7 µm
err 0.7 µm
err 0.2 µm
For ?K/K 1.5 10-4 ?xmax 195 µm ?ymax 83
µm ?gmax 0.9 µm
Conclusion Temperature excursions
permanently change the undulator fiducialization.
20
Trajectories And Phase Are OK
Undulator 39 Went through all temperature
excursions. Trajectories no significant
change Phase Errors added 1 rms
21
Storage Problem Summary
Bldg 750 re-measured undulators
The undulators in bldgs 750 and 33 must be
re-fiducialized. The trajectories and phases are
ok. The average gap changed by about 1
micron. The magnetic axis shifted by about 200
microns in x. 200 microns ? ?K/K 1.8
10-4 Tolerance ?K/K 1.5 10-4
All finished undulators are presently stored in
the MMF. A recent air conditioner shutdown does
not appear to have damaged them.
22
Tuning Work
A. Weidemann, Y. Levashov, E. Reese

• Repair undulators
• Fix shim interferences
• Re-tune
• Re-fiducialize

23
RepairsBefore repair
130µm
Two areas to replace shims
Ed Reese
24
After Repair
50µm
Ed Reese
25
X-Trajectory Shim Interference Fix
X-trajectory shim
Cut material off

• X-trajectory shims limit vacuum chamber
  in-motion to 2.5mm
• Undulators tuned for 6 mm
• Shims to be modified to allow - 6mm motion and
• Undulator tuning to be checked

26
Y-Trajectory Shim Interference Fix
New
Old
Fix, new triangles on old strongback
27
Schedule
Yellow items are done. Three undulators still
need repair. Eleven undulators have shims
replaced, are re-tuned and re-fiducialized. Two
have feet and are RFI. (The CMM has been
tied up with girders.)
28
Average Field On Each Girder In The Tunnel
S. Anderson, J. Welch
By limit
From I2y limit for constant field ?Bgapmax
0.09 G
By bench
By tunnel
Shield Atten 1/6 Pole Amplif 2.4
By limit
?Boutsidemax 0.2 G
29
Reference Undulator
Re-tuning starts
K is tuned to the same value each time, Knom
3.498623 K is adjusted for temperature and
X-position. (All errors included in the
plot.) R.M.S. 1.1 10-4
30
Conclusion

• Undulator quadrupole measurements are done.
• A transportation test showed no undulator changes
  from handling.
• Temperature excursions produce permanent
  undulator fiducialization changes.
• The magnetic field in the tunnel is within the
  range of the magnetic shield except at a few
  girders.
• Three undulators still require repairs.
• Re-tuning is roughly 1/3 done.
• Adequate undulator storage is still a problem.
  (The tunnel is our planned solution.)