1. RF phase & amplitude stability of the CTF klystrons By Dubrovskiy Alexey 4 February 20091CLIC beam physics meeting And thanks to Frank Tecker and Daniel Schulte

2. Layout of klystrons in the CTF From G. McMonagle, CLIC-Note- 694 Beam current: 3.5 A Beam frequency: 1.5 GHz RF to beam: ~440 MW Pulse length: 1.6 μs Accelerating gradient : 7 MV/m Klystron frequency: 3 GHz LIPS 40 MW LIPS 40 MW LIPS 30 MW BOC 30 MW Klystrons MKS03, MKS05, MKS06 and MKS07 are considered in this presentation x4 4 February 20092CLIC beam physics meeting

3. Single pulse 1 time unit = 10.406 ns Data were taken at 17:31:49 on Dec 12 2008 4 February 20093CLIC beam physics meeting

4. Pulse2Pulse Stability Overview 4 February 20094 MKS03 CLIC beam physics meeting MKS05 Phase Amplitude

5. Pulse2Pulse Stability Overview 4 February 20095 MKS06 CLIC beam physics meeting MKS07 Phase Amplitude

6. Pulse2Pulse. Probability density function. 4 February 20096 MKS03 CLIC beam physics meeting Phase Amplitude

7. Pulse2Pulse. Probability density function. 4 February 20097 MKS05 CLIC beam physics meeting Phase Amplitude

8. Pulse2Pulse. Probability density function. 4 February 20098 MKS06 CLIC beam physics meeting Phase Amplitude

9. 4 February 20099 MKS07 CLIC beam physics meeting Pulse2Pulse. Probability density function. Phase Amplitude

10. MKS03 Phase Analyze 4 February 200910 t685686687688689691692693694695696 μ 60.860.961.261.560.559.158.959.159.259.559.3 σ2σ2 0.0150.0210.0170.0220.0190.0180.0160.0190.0180.0120.011 t697698699700701702703704705706 μ 59.359.558.858.958.658.157.957.557.457.9 σ2σ2 0.0110.0120.0150.0190.0140.013 0.0110.0150.012 Pulse2Pulse Δμ Stability

11. 4 February 200911CLIC beam physics meeting Plots of mean values (Δμ) Phase Amplitude

12. Pulse2Pulse σ 2 Stability 4 February 200912CLIC beam physics meeting Plots of variance values (σ) Phase Amplitude

13. Pulse2Pulse σ 2 FFT 4 February 200913CLIC beam physics meeting MKS03 MKS05 Phase Amplitude

14. Pulse2Pulse σ 2 FFT 4 February 200914CLIC beam physics meeting MKS06 MKS07 Phase Amplitude

15. MKS07 FFT Analyze of σ 2 Pulse2Pulse σ 2 Stability t735736737738739740741742743744745 Hz0.0139 ∆Hz±0.0035 simple att. (deg)0.2270.19310.19440.20920.20320.19230.20080.19850.21060.20420.2132 max att.(deg)0.83870.6590.68390.83030.8450.68040.79730.75870.79650.65330.7184 err. (deg)0.37780.27270.28680.22690.260.2620.25960.21940.2590.24910.2858 t746747748749750751752753754755 Hz0.0139 ∆Hz±0.0035 simple att. (deg)0.19440.18550.17190.17390.17550.1540.1471 0.14390.1346 max att.(deg)0.67590.67270.66770.63750.88640.7340.83440.81550.69810.6527 err. (deg)0.28410.24440.20970.27760.22130.24140.27660.32660.29470.3202 4 February 200915CLIC beam physics meeting

16. σ- values after subtraction of Δμ and harmonics 4 February 200916CLIC beam physics meeting Amplitude Phase σ along pulse Pulse2Pulse σ

17. Fast pulse2pulse feed-back conditionality Klystron phase can be adjusted to the flat top by 70-90% applying a fast pulse-to-pulse feedback based on the control of phase waveform Klystron power can be adjusted to the flat top by 60-90% applying a fast pulse-to-pulse feedback based on the control of amplitude waveform 4 February 200917CLIC beam physics meeting

18. Pulse FFT for tigidou stabilization 4 February 200918CLIC beam physics meeting MKS03 MKS05 Phase Amplitude

19. Pulse FFT for tigidou stabilization 4 February 200919CLIC beam physics meeting MKS06 MKS07 Phase Amplitude

20. MKS05 phase and amplitude long term changes Klystron phase shifter Comparator phase shifter ΔP≈5 deg ΔA≈0.8 MW ΔT≈18 hours 4 February 200920CLIC beam physics meeting

21. ΔP≈8 deg ΔA≈1.2 MW ΔT≈19 hours 4 February 200921CLIC beam physics meeting MKS06 phase and amplitude long term changes

22. ΔP≈3.5 deg ΔA≈1.2 MW ΔT≈4.5 hours ΔP≈3.5 deg 4 February 200922CLIC beam physics meeting MKS07 phase and amplitude long term changes

23. Slow Pulse2Pulse Phase Stabilization. Phase loop. Klystron phase loop layout was prepared by J. Sladen in order to compensate slow RF phase variation in accelerating structures due to klystron output phase instabilities along day. 4 February 200923CLIC beam physics meeting

24. Slow Pulse2Pulse Phase Stabilization. EMA. Since the fast pulse2pulse phase deviation approximately equals to the slow phase variation, an acquisition phase averaging is required. An exponential moving average (EMA) was introduced: where {p j } is the phase acquisition values, n is a integer and 0 < k < 1. In the CTF case the sampling rate of {p j } is ~1 sec. Normally, The phase error at any acquisition moment can be introduced in the following way using a Fourier series: Fast variationSlow variation Other errors Thus, In order to archive a small error, the number n must be between the main slow and fast harmonics. And the number ε limits the quality of a feed-back, which will be based on the EMA. 4 February 200924CLIC beam physics meeting

25. Slow Pulse2Pulse Phase Stabilization. EMA. 4 February 200925CLIC beam physics meeting Acquisition phase is red. EMA is blue.

26. 4 February 200926CLIC beam physics meeting Slow Pulse2Pulse Phase Stabilization. Absolute control gain. Sufficient conditions

27. 4 February 200927CLIC beam physics meeting Slow Pulse2Pulse Phase Stabilization. The gain is a constant of 1 deg, n=100Data were taken in 2006 Phase loop is ON Phase loop is OFF

28. 4 February 200928CLIC beam physics meeting Thank you for your attention