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 Status

• Overview
• Status/Schedule
• Reference Undulator
• Undulator Repairs
• Radiation Damage

3
Re-Tuning

• We are re-tuning all the undulators
• because of
• damage from temperature excursions
• beam pipe interferences

4
Re-Tuning Schedule
28 undulators are in the tunnel 5 undulators are
still required 2 undulators need repair 6 spares
need to be tuned K vs Temperature studies still
need to be done
5
Reference Undulator
Reference Undulator measured many times
X-Trajectory, Y-Trajectory, Phase vs Z, Phase In
Cell, all stable
6
Reference Undulator
I1XvsX
I1YvsX
Field Integral Measurements, Long Coil
Reference Undulator never tuned for 6 mm
good field region
I2XvsX
I2YvsX
Field integrals stable, but some
systematic changes
7
Reference Undulator
I1X vs Time
I1Y vs Time
Field integral changes possibly due to coil
straightness
Field integrals at X0 at different times
I2X vs Time
I2Y vs Time
Started straightening coil routinely, improved rep
eatability
8
Beam Axis Position
Reference Undulator
The beam axis position relative to the tooling
balls is affected by many errors. The
repeatability of the reference undulator beam
axis position is a measure of the rms error on K
for the undulators in the tunnel.
9
Undulator Tooling Balls Relative To Beam Axis
Reference Undulator
10
Change In Beam X Position Relative To X Tooling
Balls
Reference Undulator
Average change doesnt affect performance. RMS
change is important.
11
Change In Beam Y Position Relative To Y Tooling
Balls
Reference Undulator
12
MMF Temperature History
Reference Undulator
Aside The 9 degree temperature excursion in
December 2008 caused a one month delay while we
recalibrated, straightened the bench, and checked
all the undulators in the MMF. The smaller
temperature excursions caused a one week delay
each while we checked our calibrations.
13
MMF Temperature Excursions T gt 22 C
Reference Undulator
The large temperature excursions are
not responsible for the slope in the beam axis
x-position plot.
deg C
14
Hall Probe Calibrations
Reference Undulator
The hall probe was calibrated several
times during the tuning. The changes in
x-position remained. Hall probe calibration
errors do not appear to be responsible for the
change in beam axis x-position.
15
MMF Temperature Accuracy
Reference Undulator
Yurii compared our temperature measurement system
output to a reference thermometer on 4/16/09. The
temperature difference is shown. We have done
similar tests in the past, with similar
results. There does not appear to be any
significant error in our temperature measurements
.
T Read Refere Differ 1 19.96 19.958
0.002 2 19.97 19.966 0.004 3 19.96
19.956 0.004 4 19.94 19.943 -0.003 5
19.93 19.931 -0.001 6 19.88 19.875
0.005
deg C
16
Kugler Bench Reference Dipole
Reference Undulator
Reference Dipole, uniform field, NMR measurements
(Bhall Bnmr) / Bnmr is stable to better
than 10-4 over the past year.
17
Hall Probe Calibration History
Reference Undulator
a)
c)

• Bcalib Bnom vs Vhall
• Bnom is linear in V. (Take
• out linear part of calibration.)
• See some changes in probe.
• At V 5 V (1 T), change in
• calibration over time. See an
• ageing of probe. Calibration
• takes this out.
• Residuals Bmeas Bfit
• Residuals less than 0.2 G.

b)
18
SN16 Radiation Damage Test
Heinz-Dieter will comment on the dose and the
number of equivalent years of usage.
19
SN20 Radiation Damage Test
Heinz-Dieter will comment on the dose.
20
Undulator Repairs
Straightness Repairs Are Complete 6 Undulators
Before
After
21
Undulator Repairs
SN6 needs the end pole assemblies
re-installed. SN4 needs a pole repaired. We are
setting up a lab to do this work. In addition,
we will install a block magnetizer and
a helmholtz coil in this lab to repair undulators
and allow prototype development.
22
Conclusion

• 28 undulators are in the tunnel
• 33 undulators will be installed in July
• Reference undulator trajectories and phases are
  stable
• Reference undulator axis position indicates rms
  ?K/K errors of 310-5 for production run 2
• MMF temperature measurements appear accurate by
  comparing to a reference thermometer
• Reference dipole measurements are stable to 10-4
  determined by comparing the hall probe to an NMR.
• Hall probe calibration fits have residuals less
  than 0.2 G.
• The hall probe shows some ageing with time. (The
  calibrations correct this.)
• A radiation damage test was done and no damage
  was detected.
• The final undulator repairs are in progress.
• Studies of K vs temperature will start as soon as
  the production work is done.
• We need to tune 6 spare undulators and then we
  are ready for routine radiation damage checks.
• We will be able to fix undulators and build small
  prototypes with our fixturing and block
  magnetizer.