Transcript Requirements for the MMF

LCLS Magnetic Measurement Facility
Requirements
Functional
Temperature
Vibration
Earth's Field
10/14/04
Talk MMF Requirements
J. Welch
[email protected]
Functional Requirements
During LCLS Construction
Tune and measure undulator segments (40x)
Fiducialize segments and quadrupoles (~80x)
Assemble and align components (~40x)
Vacuum chambers, BPMs, quadrupoles, undulator
segments, diagnostics boxes, cradles
Store some ready-to-go assemblies (~10x)
During Operation
Undulator segment validation program (1-3/month)
New undulator magnets
Other work for SLAC
10/14/04
Talk MMF Requirements
J. Welch
[email protected]
Temperature Requirements
Stability and Accuracy
Set point and range
10/14/04
Talk MMF Requirements
J. Welch
[email protected]
Temperture Stability and Accuracy
Strength tolerance is |∆K/K| <= 1.5 x 10-4 for 10
degrees phase error per undulator segment
Temperature coefficient of remanence of NdFeB is 0.1%/C,
which, because of partial compensation via Ti/Al assembly,
leads to a measured undulator temperature coefficient of
∆K/K = -5.5 x 10-4/˚C,  |∆T| <= 0.27 ˚C
Ambient air determines magnet temperature
Undulator Hall is spec'd at |∆T| <= 0.2 ˚C
Therefore MMF is spec'd at |∆T| <= 0.1 ˚C,
Temperature control must be absolute and long term.
Only selected areas within MMF require this level of
control. CMM area needs ±1.0˚C.
10/14/04
Talk MMF Requirements
J. Welch
[email protected]
Temperature Averaging
The segments have a
slow thermal response
time
Probes may be faster.
Short term
temperature
fluctuations are
allowed up to ±0.3 ˚C
for less than 1 hour.
10/14/04
Talk MMF Requirements
J. Welch
[email protected]
Temperature Set Point
Temperture must match
Undulator Hall year round
20.0 C chosen to match
metrology standard
Most people will find it too
cold in the summer
10/14/04
Talk MMF Requirements
J. Welch
[email protected]
Range of Set Points
Measure the temperature coefficients of
undulator segments in the future.
HVAC should have a set point range from
18.5 - 22.5 ˚C
10/14/04
Talk MMF Requirements
J. Welch
[email protected]
Vibration
Ambient vibration requirements set by probe
stability ≤ 0.5 m rms.
Transient requirements set at 3.0 m rms, not
more often than 1 every 20 seconds. Repair
of nearby "potholes" is called for.
10/14/04
Talk MMF Requirements
J. Welch
[email protected]
Earth's Magnetic Field
Earth's field must be corrected for at the level
of 0.1 gauss or less
The components in the horizontal plane are
North 0.23 gauss, East 0.06 gauss. (Vertical
0.43 gauss is presumed same in MMF as
UH). UH is 7.56 degrees off E-W line (WSWENE)
Plan to align the measurement bench with
Undulator hall, and avoid distorting the Earths
field with large nearby steel components.
10/14/04
Talk MMF Requirements
J. Welch
[email protected]