1. Status of the PS TFB Hardware Overview Machine results To be done
J. Belleman, E. Benedetto, F. Caspers, D. Glenat, R. Louwerse,
M. Martini, E. Métral, V. Rossi, J. Sladen, J.M. Nonglaton
Acknowledgments:
R. Steerenberg, S. Gilardoni
Hardware Overview
Machine results
To be done
Alfred Blas
APC 30/1/2009

2. PS TFB Block diagram Green boxes represent devices to be completed
Alfred Blas
APC 30/1/2009

3. PS TFB Hardware setup PS TFB Power + electronics 355-R-017
Clock distribution PS CB
Hardware setup
Power + electronics 355-R-017
Kickers + transformers PS SS 97
Water distribution 355-R-017
Alfred Blas
APC 30/1/2009

4. PS TFB Pick-up amplifiers J. Belleman BW: 20 kHz – 40 MHz
80 dB dynamic range (compatible with ions)
Remotely programmable gain
Located in the ring below concrete slab
Alfred Blas
APC 30/1/2009

5. PS TFB
DSPU hardware V. Rossi
Alfred Blas
APC 30/1/2009

6. PS TFB DSPU firmware Green boxes represent functions to be completed
Alfred Blas
APC 30/1/2009

7. PS TFB Clock generation J. Sladen 1 GHz DDS
Receives the frequency program from the PS central building and outputs the 160*Frev (< 80 MHz).
Clock Generator
Transforms 10 MHz into 1 GHz
Alfred Blas
APC 30/1/2009

8. PS TFB Pre-Amplifier Fast Clipping of the output signal
0 and 180o outputs
Programmable gain
TFM setup
Local / Remote control
Interface with the PLC control
Alfred Blas
APC 30/1/2009

9. PS TFB Power Amplifier R. Louwerse [2.5 kHz – 25 MHz],
3kW – 2ms, 800W – CW
Alfred Blas
APC 30/1/2009

10. PS TFB Impedance matching transformers R. Louwerse
Input impedance: 50 Ω
Output impedance: 100 Ω
[ 2kHz – 40 MHz] 3 kW
Alfred Blas
APC 30/1/2009

11. PS TFB
Kicker F. Caspers, V. Bretin
Alfred Blas
APC 30/1/2009

12. PS TFB
Kicker
Alfred Blas
APC 30/1/2009

13. PS TFB Power loads 50 Ω / 30 dB Attenuator
[ DC – 1GHz] 1 kW CW
100Ω to 50Ω resistive transition
[ DC – 190 MHz] 1.6 kW CW
Alfred Blas
APC 30/1/2009

14. PS TFB
PLC Power Control D. Glenat
Alfred Blas
APC 30/1/2009

15. PS TFB
Operation display
J. M. Nonglaton
Alfred Blas
APC 30/1/2009

16. PS TFB Results: Automatic delay Resolution=0.4ns
Measurement time: 22 us
Maximum jitter : 260 ps
Precision requirement:
1.1 ns for 10o error at 25 MHz
Alfred Blas
APC 30/1/2009

17. PS TFB Machine Results Auto Dly + Hilbert
The proper functioning of the automatic delay has been tested during an MD on MDPS (22/09/08) with a copy of the SFTPRO beam.
The beam transfer function was measured on the 3.5 GeV plateau and on the 14 GeV plateau.
If the phase response of all betatron lines can be superimposed, the delay is correct.
The parameters of the automatic delay were set at 3.5 GeV for a proper phase response and the measurements made again at 14 GeV proved that the circuit behaved as expected.
The measurements made another day at 1.4 GeV gave the same positive results.
BTF of a Q+q betatron line
Alfred Blas
APC 30/1/2009

18. PS TFB
Results: Notch Filter
Alfred Blas
APC 30/1/2009

19. PS TFB Results: Hilbert Filter M= 3 Hilbert
Without Notch Filter – set value = 45o
With Notch Filter – set value = 45o
Alfred Blas
APC 30/1/2009

20. PS TFB Results: Hilbert Filter M= 1 Hilbert
Without Notch Filter – set value = 45o
With Notch Filter – set value = 45o
Alfred Blas
APC 30/1/2009

21. PS TFB Sensitivity to Q measurement
With the PU in SS98 and the kicker in SS97, the ideal betatron phase lag within the TFB path can be expressed as follow (qH,V Є [0 , 0.5]):
ΔφB-TFB = o + (536.4o * q) in the case of no delay for the dephasing (2 PUs!)
ΔφB-TFB = o + (896.4o * q) in the case of 1TREV delay for the dephasing (m=1 Hilbert)
ΔφB-TFB = o + (1616.4o * q) in the case of 3TREV delay for the dephasing (m=3 Hilbert)
9o phase error for an error in q of with the m=1 Hilbert
( <=> 4.5 kHz error in the FFT)
One measurement made on LHC25. 11/11/08
The Q measurements are supposed to have a precision of 100ppm
Unfortunately during the tests we had a jitter from cycle to cycle
The rf clock of the Q measurement doesn’t take into account the loop errors of the RFLL.
Is this the explanation?
Alfred Blas
APC 30/1/2009

22. PS TFB Results 30mm p-p initial H error
MDPS 1.4 GeV flat cycle with no Chromaticity and no coupling
23/10/08
PSB MD1 beam p injected (3 turns in R3)
Injection error obtained by setting PI.KFA45 to 270 kV instead of 300 kV
Inj. error Damping: 1.4 GeV (21mm/ms required for the most demanding case: Pilot beam εn = 0.8μm)
Power system used for controlled blow-up (slow extraction) and Q measurement
500 μs/div
From M. Martini
APC 26/5/2005
Alfred Blas
APC 30/1/2009

23. PS TFB Results 30mm p-p initial H error 500 μs/div
Zoom top = h position bottom = kick μs/div
Alfred Blas
APC 30/1/2009

24. PS TFB Results MD 11/11/2008 E. Metral
With coupling – No TFB
Without coupling – No TFB
LHC25 injection plateau at 1.4 GeV with linear H/V coupling (Iskew =-0.3)
Without coupling (Iskew = +0.3)
See logbook for more details (11/11/08)
Last plot taken from a good shot; not always the case (The Betatron phase was set to an empirical fixed value!)
Without coupling – With TFB
Alfred Blas
APC 30/1/2009

25. PS TFB Results MD 11/12/2008 Q measurement Only the H plane is excited
Without coupling – No TFB
Only the H plane is excited
Alfred Blas
APC 30/1/2009

26. PS TFB
Conclusion
The MDs on the machine show that the PSTFB fulfills the expected requirements:
Kick efficiency
Automatic delay
Hilbert filter
Remote control of the DSPU and of the Power system
Usage of the power system for the Q measurements and controlled blow-up
Improvements for 2009:
Hardware
2 fully loaded DSPU modules instead of the single beta version.
2nd input on the DSPU with a serial delay for the 2nd PU. ( -> lower sensitivity to Q value)
3rd and 4th inputs on the DSPU for the PU SUM signals (normalization of the Delta signal)
DSPU input impedance varies with the input attenuation (52 -> 72Ω)
Install a driver for a better compatibility with the Q measurement excitation
Firmware
Notch filter could be modified for a more suitable phase response
Q-to-Hilbert-phase LUT should be adapted to take into account the phase errors of the Hilbert (with respect to the command) together with the response of the Notch.
Software
Q (h and V) measured along the cycle (0.01 precision) and value sent to a GFAS (PA.GSTFBH and PA.GSTFBV)
PU control knob to be created (Automatic gain as a function of peak beam intensity ?)
Other
Q measurement (rev clock used for the sampling of the beam signal precise enough ?)
Alfred Blas
APC 30/1/2009