1. Status of the TESLA Magnet Package and Vibrations at TTF
H. Brueck
Dec,

2. Topics The TESLA magnet package
Current leads
Prototype tests
Results and plans of vibration measurements
Dec 6, 2004
H. Brueck, DESY, MKS

3. Summary on TESLA Magnet Package
Magnet is ready
should arrive this week
Aluminum Cylinder
quadrupole gradient
63.5 T/m
quadrupole current
100 A
quadrupole inductance
~ 2.53 H
dipole field
0.11 T
dipole current
40 A
dipole inductance
~29 mH
max. field at conductor
3.22 T
field length
0.52 m
alignment error (angle)
0.1 mrad rms
Connection plate
side
Dec 6, 2004
H. Brueck, DESY, MKS

4. Summary on TESLA Magnet Package
Iron yoke blocks
Superconducting coil
Aluminum Cylinder
Dec 6, 2004
H. Brueck, DESY, MKS

5. Summary on TESLA Magnet Package
Coils and connection plate before it was assembled
Dec 6, 2004
H. Brueck, DESY, MKS

6. Summary on TESLA Magnet Package
Magnet is ready
should arrive this week
Warm and cold tests planed at DESY for December and January 05
Cryostat
design done by a Spanish firm (TTM)
Reviewed by CIEMAT, TTM will send drawings to DESY for a final review
Fabrication at TTM until end of January 05
Two weeks for final assembly needed at CIEMAT
Complete Magnet Package could be at DESY end of February 05
Future plans with the package
Original foreseen for module 6
Now we propose to put it to module 10 (“FNAL module”)
As this module will be assembled later, there would be time to send it to SLAC
SLAC asked for a TESLA type magnet for measurements of the motion of the axis with respect to the beam when the field is varied
We need to discuss how to proceed here (I’m at CIEMAT next week)
Problem: one needs a special vacuum tank
Dec 6, 2004
H. Brueck, DESY, MKS

7. Summary on Current Leads
Prototype test at DESY, operated up to 150A
Problem with cold feed through
For the assembly in a module Ciemat has no HTS material available, checking if they can get more
The “6 in one” assembly not yet designed, only the solution we are presently testing could be made
I’ve contacted Mark & Wedell, that produces CERN 60A leads
They are willing to give us one lead assembly (4 leads) out of the CERN production, but CERN has to agree
No answer yet
Dec 6, 2004
H. Brueck, DESY, MKS

8. Magnet Test Program at DESY
Warm measurements (AC, low current)
Harmonics
Try axis and roll angle measurements (Stretched Wire)
Followed by detailed cold test in a vertical bath cryostat (4K and 2K)
cold harmonics with various currents and conditions
finally quench tests
Power supplies and electronics
Test insert
Warm finger and
pick-up coil
Dec 6, 2004
H. Brueck, DESY, MKS

9. Status from Vibration Measurements during shutdown (Sep 2004)
Measurements at ACC 4 only
Data acquisition close to sensors
Two sensors (cold) at the quadrupole vertical and transverse to the beam
Two sensors on top of the module
Two sensors on the ground/support
One geophone (vertical) at various places
Measurements with various conditions
Comparison Piezo - Geophone
Day, night weekend
Vacuum pumps on, off, pumps dismounted from trailer
Dec 6, 2004
H. Brueck, DESY, MKS

10. Conditions PC now close to sensors
Preamplifier switched from acceleration to velocity
Implies a high pass at 1 Hz (.2 Hz in acc mode)
Low pass filter at 1 kHz
Data analysis
Just FFT, ignoring non periodic effects, no corrections, no window-functions
Averaging over many measurements
Dec 6, 2004
H. Brueck, DESY, MKS

11. 2 Piezos and a Geophone on the socket
RMS average, Saturday midnight ± 1 hour
Piezo blue and pink, Geophone red
Good agreement between
the two piezos
piezo and geophone (20%)
Low RMS: nm for f>2Hz
Comparable with ground motions measured by Ehrlichmann
At low frequencies the noise signal is probably getting dominant
Dec 6, 2004
H. Brueck, DESY, MKS

12. Ground Vibration time dependence Friday to Monday, RMS f>2Hz
Friday | Saturday | Sunday | Monday
100nm
20nm
15:00 20:00 1:00 6:00 13:00
15:00 20:00 1:00 6:00 13:00
15:00 20:00 1:00 6:00 13:00
Dec 6, 2004
H. Brueck, DESY, MKS

13. Comparison of Piezo and a Geophone on top of the module (vertical)
RMS average, satuday midnight ± 1 hour
Sensor positions on top of the module
Good agreement, also Geophone and Piezo positions are not identical
RMS: 115 nm for f>2Hz
2-3 time larger as at lower position (different weekend)
Dec 6, 2004
H. Brueck, DESY, MKS

14. Check influence of the Pump stand
Vibrations of the vacuum trailer generates a torque on the Schiebemuffe
Long lever arm
Vertical bellow fixed by bolts
Dec 6, 2004
H. Brueck, DESY, MKS

15. Pump stand modifications
Pump moved from trailer to floor
Connected via a thin flexible line
Frequency converter moved to the floor
Internal dampers plus additional foam
Dec 6, 2004
H. Brueck, DESY, MKS

16. RMS average, midnight ± 1 hour
Pump stand without/with modifications Vertical Sensors (2 different days)
RMS average, midnight ± 1 hour
Sensors:
Cold
Top
Socket
Geophone Socket
without
with
Different days
Mon “without”
Tue “with”
Cold Signal *3
Some reduction below 25 Hz
Large reduction between 25 and 50 Hz
Dec 6, 2004
H. Brueck, DESY, MKS

17. RMS average, midnight ± 1 hour
Pump stand without/with modifications Horizontal Sensors (2 different days)
RMS average, midnight ± 1 hour
Sensors:
Cold
Top
Socket
without
with
Different days
Mon “without”
Tue “with”
Horizontal vibrations much larger
Cold Signal *3
Some reduction below 25 Hz
Large reduction between 25 and 50 Hz
Dec 6, 2004
H. Brueck, DESY, MKS

18. Schematic View The horizontal vibrations are larger (about factor 1.5)
Sensors on top
The horizontal vibrations are larger (about factor 1.5)
Cold mass essentially hanging
Horizontal movements less constraint
300 mm tube
Quadrupole
Cold sensors
Sensors on the socket
socket
Dec 6, 2004
H. Brueck, DESY, MKS

19. Present Summary
Good agreement between the Geophone (our reference) and the Piezo in the frequency range from 2 to 100 Hz
at various positions
for averaged RMS and RMS vs. time
Cultural noise day/night/weekend
All in all data reliable
Influence of vacuum pumps clearly seen
Effect vanishes after modifications
Pumps on/off not different anymore, which means Turbo pump has no effect
Next step
Excite module by forced vibrations using a motor with eccentric mass and tunable frequency
Soft- und hardware prepared and tested at a HERA dipole
Measurement schedule at TTF in shutdown in the week before Xmas
Dec 6, 2004
H. Brueck, DESY, MKS

20. Forced Vibrations of a HERA Dipole Cryostat up to 20Hz
Strong resonance observed at about 14.5 Hz
Dec 6, 2004
H. Brueck, DESY, MKS

21. Forced Vibrations of a HERA Dipole Cryostat up to 60Hz
Different measurements with decreasing eccenter mass
Dec 6, 2004
H. Brueck, DESY, MKS

22. Forced Vibrations of a HERA Dipole Cryostat, RMS and Spectrum
Dec 6, 2004
H. Brueck, DESY, MKS