RF Control for the DESY UV-FEL Stefan Simrock DESY DESY CASA - - PowerPoint PPT Presentation

▶
rf control for the desy uv fel
SMART_READER_LITE
LIVE PREVIEW

RF Control for the DESY UV-FEL Stefan Simrock DESY DESY CASA - - PowerPoint PPT Presentation

Jul 08, 2023 8 likes •762 views

RF Control for the DESY UV-FEL Stefan Simrock DESY DESY CASA Seminar 2/6/04 Stefan Simrock DESY UV-FEL Configuration of the RF Systems Requirements for RF Control Design of the LLRF Issues for the European X-FEL

slide-1
SLIDE 1

CASA Seminar 2/6/04 Stefan Simrock DESY

RF Control for the DESY UV-FEL

Stefan Simrock DESY

slide-2
SLIDE 2

CASA Seminar 2/6/04 Stefan Simrock DESY

  • DESY UV-FEL
  • Configuration of the RF Systems
  • Requirements for RF Control
  • Design of the LLRF
  • Issues for the European X-FEL
  • Outlook
slide-3
SLIDE 3

21 Jan. 2004

  • J. Rossbach: TTF2 Status Report

3

Status of beamline installations

250 m RF gun FEL experimenta l area bypass undulator s collimator

bunch compressor

Laser

M1 M2 M3 M4 M5 M6 M7 bunch compressor

1000 MeV 4 MeV 150 MeV 450 MeV

slide-4
SLIDE 4

CASA Seminar 2/6/04 Stefan Simrock DESY

General LLRF Requirements

  • Set and maintain accelerating fields during TTF II
  • peration as
  • UV FEL user facility
  • Tesla Test Facility
  • Cavities to be controlled:
  • RF Gun (nc)
  • 3rd harmonic cavity (3.9 GHz)
  • Vector-sum of cryomodule 1
  • Vector-sum of cryomodules 2+3
  • Vector-sum of cryomodules 4,5,6,(7)
  • S-Band cavity (nc) at 2.856 GHz
  • Provide stable phase reference for Laser, and diagnostics
slide-5
SLIDE 5

21 Jan. 2004

  • J. Rossbach: TTF2 Status Report

4

Electron gun for minimum emittance: PITZ

PITZ gun installed into TTF Jan 2004

slide-6
SLIDE 6

TTF2 RF GUNAT PITZ

Jean-Paul Carneiro Behavior of the TTF2 RF with long pulses and high repetition rates.

slide-7
SLIDE 7

21 Jan. 2004

  • J. Rossbach: TTF2 Status Report

5

TTF 2 Laser Upgrade

diode-pumped Nd:YLF preamplifier Pulse shaper (T = 5%) Diode-pumped Nd:YLF oscillator

E

micro = 16µJ

P = 16 W

AOM

fround trip = 27 MHz

EOM AOM

Faraday pulse picker pulse picker 2-stage flashlamp-pumped Nd:YLF booster amplifier

fast current control shot-to-shot

  • ptimizer

2-stage diode-pumped Nd:YLF amplifier

fast current control

fourth harm. E

micro = 200µJ

P = 200 W 20 ps flat-top 4 ps edges Emicro = 30µJ Eburst = 24 mJ UV (262 nm)

pump diode pump diode pump diode pump diode pump diode pump diode pump diode pump diode

Pulse Stacker

Note: longitudinal flat profile by pulse stacker only

  • Together with Max-Born-Institute,

Berlin (I. Will et al.)

  • Upgrade has been tested at PITZ
slide-8
SLIDE 8

21 Jan. 2004

  • J. Rossbach: TTF2 Status Report

8

Transverse Emittance Measurement @ PITZ

  • 1.

7 1. 5

slide-9
SLIDE 9

Frank Stephan TESLA meeting, Zeuthen, Jan. 2004 21

transverse profile ( D=1.2 mm ) FWHM 21 ps; rise/fall time 7 ps

mm 0.02 0.61 σ mm 0.02 0.55 σ

y x

  • Fine Tuning of Laser Parameters

( measured in UV )

slide-10
SLIDE 10

CASA Seminar 2/6/04 Stefan Simrock DESY

General LLRF Requirements (Cont’d)

  • The LLRF System for the FEL user facility must be
  • Reliable
  • Operable
  • Reproducible
  • Maintainable
  • Well Understood
  • Meet (technical) performance goals
  • The LLRF System for the TESLA Test facility must
  • demonstrate high gradient operation at 35 MV/m
  • requires piezo tuners for Lorentz force compensation
  • requires operation close to klystron saturation
  • exception handling
  • Demonstrate of operation with electronics installed in tun-

nel

slide-11
SLIDE 11

21 Jan. 2004

  • J. Rossbach: TTF2 Status Report

10

LLRF Requirements:

Support by: ELHEP Group

Warsaw University of Technology Institute Electronic System

Team: About 20 people scientists, engineers and students (Ph.D. and M.Sc.) working at: Warsaw, CERN, DESY

slide-12
SLIDE 12

CASA Seminar 2/6/04 Stefan Simrock DESY

Amplitude and Phase Stability

  • Typically requirements are
  • σA/A < 10-3 amplitude
  • σφ < 0.3 deg. for phase (fast fluctuations)
  • Must distinguish correlated and uncorrelated errors, intra-pulse, inter-pulse,

and long-term (thermal > minutes). Long term stability of better than 1 deg. is difficult to achieve.

  • Other requirements
  • ACC1: cav. 1-4 at 12.5 MV/m, cav. 5-8 at 20 MV/m phase
  • f accelerating field -10.8 deg.
  • ACC39 at 14 MV/m at 183 deg.
  • S-Band cavity at 2856 MHz phase stability < 1 deg.
  • RF Gun operation without field probe. Rep. rate, pulse

length and power must be variable.

slide-13
SLIDE 13

TTF2 linac

2nd bunch compressor (internally called BC3)

bypass undulators collimator

M1 M2 M3 M4 M5 M6 M7 Laser RF-Gun

1st bunch compressor (internally called BC2)

bunch compressor (internally called BC2)

250 m

slide-14
SLIDE 14

21 Jan. 2004

  • J. Rossbach: TTF2 Status Report

30

Magnetic chicane for longitudinal compression

slide-15
SLIDE 15

21 Jan. 2004

  • J. Rossbach: TTF2 Status Report

33

Temporary beamline for seeding Beam dump

slide-16
SLIDE 16

21 Jan. 2004

  • J. Rossbach: TTF2 Status Report

24

Longitudinal bunch shape measurements at TTF2

  • Streak camera

–FESCA 200 (Hamamatsu)

  • Transverse deflecting cavity

–S-band travelling wave cavity from SLAC

  • Coherent radiation

–Interferometer from RWTH Aachen

  • Electro-optical sampling
slide-17
SLIDE 17

21 Jan. 2004

  • J. Rossbach: TTF2 Status Report

25

LOLA Shipment from SLAC to DESY

  • Vertically deflecting cavity for bunch length

measurements at TTF2

  • Built in the late 60ies by G. Loew et al.
  • SLAC contribution to TTF2

“Intra-Beam Streak Camera” e e−

−

σ σz

z

3.66 m 3.66 m V V( (t t) ) σ σy

y

RF RF ‘streak’ ‘streak’

S S-

  • band

band

transverse RF deflector transverse RF deflector

β βc

c

β βp

p

∆ ∆ψ ψy

y

slide-18
SLIDE 18

21 Jan. 2004

  • J. Rossbach: TTF2 Status Report

26

LOLA shipment LOLA installed

slide-19
SLIDE 19

21 Jan. 2004

  • J. Rossbach: TTF2 Status Report

29

Electro-optical sampling at TTF1

  • Ti:Saphire laser (15 fs) and ZnTe crystal
  • Electron bunch can be scanned by varying the delay of the laser
  • Polarization of the laser changes depending on the amplitude of the

“beam fields“

Signal

slide-20
SLIDE 20

21 Jan. 2004

  • J. Rossbach: TTF2 Status Report

35

Task Name

vacuum installation ACC1 string assembly ACC1 tunnel installation coupler conditioning (warm) cool down coupler conditioning (cold) cavity conditioning gun commissioning (nighttime) gun commissioning with beam injector commissioning incl. BC2 tunnel closed beam through ACC1 final installation commssioning entire machine beam through bypass into dump beam through undulator into dum first lasing (30 nm) FEL saturation (30 nm)

4/21 9/11 9/27 12/10 2 1 11 21 1 11 21 1 11 21 1 11 21 1 11 21 1 11 21 1 11 21 1 11 21 1 11 21 1 11 21 1 11 21 1 11 21 1 11 21 1 11 21 Jan '04 Feb '04 Mar '04 Apr '04 May '04 Jun '04 Jul '04 Aug '04 Sep '04 Oct '04 Nov '04 Dec '04 Jan '05 Feb '05

Major schedule for TTF2 installation and commissioning

More detailed schedule (400 items) to be presented in WG3 by M. Körfer

slide-21
SLIDE 21

JLAB, Nov. 2001 Stefan Simrock DESY

Typical Parameters in a Pulsed Linac

time flat-top fill cavity phase accelerating voltage incident power cavity detuning beam pulse ampl. ... Beam Loading Beam pulse pattern (micro and midi pulse structure)

slide-22
SLIDE 22

JLAB, Nov. 2001 Stefan Simrock DESY

Sources of Perturbations

  • Beam loading
  • Beam current fluctuations
  • Pulsed beam transients
  • Multipacting and field emission
  • Excitation of HOMs
  • Excitation of other passband modes
  • Wake fields
  • Cavity drive signal
  • HV- Pulse flatness
  • HV PS ripple
  • Phase noise from master oscillator
  • Timing signal jitter
  • Mismatch in power distribution
  • Cavity dynamics
  • cavity filling
  • settling time of field
  • Cavity resonance frequency change
  • thermal effects (power dependent)
  • Microphonics
  • Lorentz force detuning
  • Other
  • Response of feedback system
  • Interlock trips
  • Thermal drifts (electronics, power

amplifiers, cables, power transmission system)

slide-23
SLIDE 23

JLAB, Nov. 2001 Stefan Simrock DESY

Pulsed Operation at High Gradients

0.5 1 1.5 2 5 10 15 20 25 Cavity Gradients (First Cryomodule) time [ms] Eacc [MV/m]

0.5 1 1.5 2 −150 −100 −50 50 100 150 Cavity Phases (First Cryomodule) time [ms] phase [deg.]

+140deg./ms 0 µs flattop

  • 100deg./ms

900 µs flattop

  • 22.5 MV/m

Gradient (8 cavities)

short pulse

Phase (8 cavities)

slide-24
SLIDE 24

JLAB, Nov. 2001 Stefan Simrock DESY

Measurement of Cavity QL and Detuning

200 400 600 800 1000 1200 1400 1600 1800 2000 10

−2

10

−1

10 10

1

10

2

time [us] log( E_acc )

field decay: ~ e-t/τ τ QL π f ⋅

  • =

slope: 1 τ

  • –
  • rel. error < 1%

200 400 600 800 1000 1200 1400 1600 1800 2000 50 60 70 80 90 100 110 120 130 140 150 time [us] phase [deg]

phase with respect to LO ⇒ ∆ω = dϕ dt

  • 2π ∆f

⋅ = slope: dϕ dt

  • rel. error < 2 Hz

Loaded Q Detuning

slide-25
SLIDE 25

JLAB, Nov. 2001 Stefan Simrock DESY

Lorentz Force Detuning

500 1000 1500 2000 −300 −200 −100 100 200 300 time [µs] detuning [Hz] Lorentz Force Detuning of D39 in Chechia fill: 500 µs flat: 800 µs

15 MV/m 20 MV/m 25 MV/m 30 MV/m

fill flat-top decay

slide-26
SLIDE 26

JLAB, Nov. 2001 Stefan Simrock DESY

Digital Control at the TTF

DAC DAC

Re Im

Cavity 32

......

8x

Cavity 25

klystron

vector modulator master

  • scillator

1.3 GHz

Cavity 8

......

8x

Cavity 1

cryomodule 4

...

cryomodule 1

. . . .

LO

1.3 GHz + 250 kHz 250 kHz

ADC

f = 1 MHz

s

. . . .

...

vector-sum

Σ

( )

a b a -b 1 8

( )

a b a -b 25

( )

a b a -b 32

( )

a b a -b

DSP system

setpoint table gain table feed table forward

+ +

digital low pass filter Im Re Im Re Im Re

clock

LO

ADC

LO

ADC

LO

ADC

Im Re

power transmission line 1.3GHz field probe

slide-27
SLIDE 27

JLAB, Nov. 2001 Stefan Simrock DESY

240 270 300 330 Module 2

1 2 3 4 5 6 7 8

Beam Transient based Phase and Gradient Calibration

time Eacc Pinc Ibeam (open loop) φcav

beam induced transient

cavity filling field decay beam induced transient Re(Eacc)

φbeam

∆Vind I ∆t r Q

   π f ⋅ ⋅ ⋅ ⋅ =

for ∆t << τcav :

slide-28
SLIDE 28

JLAB, Nov. 2001 Stefan Simrock DESY

Single Bunch transient Detection

field probe (1300 MHz) delay line power divider phase shifter combiner 60 dB LO I Q Magnitude

  • f transient

Transient Vector Detector Klystron few ns cavity

Principle of high resolution transient detector

−40 −20 20 40 60 0.24 0.245 0.25 0.255 0.26 0.265 0.27 0.275 0.28 0.285 0.29 time [nsec] amplitude [arb. units]

Amplitude Single Bunch Transient ( ∆A/A=0.1%)

slide-29
SLIDE 29

JLAB, Nov. 2001 Stefan Simrock DESY

Single Bunch transient Detection

field probe (1300 MHz) delay line power divider phase shifter combiner 60 dB LO I Q Magnitude

  • f transient

Transient Vector Detector Klystron few ns cavity

Principle of high resolution transient detector

−40 −20 20 40 60 0.24 0.245 0.25 0.255 0.26 0.265 0.27 0.275 0.28 0.285 0.29 time [nsec] amplitude [arb. units]

Amplitude Single Bunch Transient ( ∆A/A=0.1%)

slide-30
SLIDE 30

CASA Seminar 2/6/04 Stefan Simrock DESY

LLRF for TTF II

  • Digital Feedback
  • C67 based DSP board
  • 8 channel ADC boards
  • 8 channel DAC board
  • Gigalink interface between boards
  • Downconverter based on AD 8343
  • Master Oscillator and Frequency Distribution
  • New Frequencies 13.5 MHz and 2856 MHz
slide-31
SLIDE 31

Zeuthen, Jan. 2004 Stefan Simrock DESY

C67 DSP board

slide-32
SLIDE 32

Zeuthen, Jan. 2004 Stefan Simrock DESY

C67 DSP board

slide-33
SLIDE 33
slide-34
SLIDE 34

Zeuthen, Jan. 2004 Stefan Simrock DESY

Rack Layout and Cabling for TTF I

slide-35
SLIDE 35

Zeuthen, Jan. 2004 Stefan Simrock DESY

Installation Status of LLRF for ACC 2-6

slide-36
SLIDE 36

FB and FF Scheme

Daniel Kotthaus

No probe in the cavity Vacc=Vfor+Vref Feedback on Vfor (later with Vacc ?) with variable Gp and GI Feedforward on Vfor adaption of FF with Vref

slide-37
SLIDE 37

Detectors for Gun Control

  • The same detectors for forward and reflected power
  • Field control with IQ detectors (AD 8347)
  • Measurement of Loaded Q and detuning with logarithmic

amplitude and phase detector (AD 8302)

  • Modern phase detector (HMC 439) for phase monitoring
  • Detector diode for amplitude monitoring

Daniel Kotthaus

slide-38
SLIDE 38

Performance of the IQ Detector

Daniel Kotthaus

slide-39
SLIDE 39
slide-40
SLIDE 40

Zeuthen, Jan. 2004 Stefan Simrock DESY

FPGA based RF Gun ControllerFPGA

slide-41
SLIDE 41

JLAB, Nov. 2001 Stefan Simrock DESY

Performance at TTF (1)

200 400 600 800 1000 1200 1400 1600 1800 5 10 15

400 600 800 1000 1200 11 11.5 12 12.5

time [µs]

Zoomed Region

accelerating gradient [MV/m]

  • nly feedback

(gain = 70) with feedback and feedforward compensation beam 500 1300 900 1700

300 500 1100

200 400 600 800 1000 1200 1400 1600 1800 −15 −10 −5 5

Zoomed Region with feedback and feedforward compensation

  • nly feedback

(gain = 70)

400 600 800 1000 1200 −1 −0.5 0.5 1

beam

time [µs]

500 1300 900 1700

300 700 1100

accelerating phase [deg]

Amplitude Phase

slide-42
SLIDE 42

JLAB, Nov. 2001 Stefan Simrock DESY

Adaptive Feedforward

time [µs] time [µs]

Step Step Response

200 400 600 800 1000 1200 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2

measured

Closed Loop System

Vector Sum Real

200 400 600 800 1000 1200 200 400 600 800 1000 1200

calculated for a linear time-invariant System

∆E τ1 ( ) ∆E τ2 ( ) … ∆E τn ( ) T11 T12 … T1n T21 T22 … T2n … … … … Tn1 Tn2 … Tnn ∆ ff 1 ∆ ff n … ∆ ff n =

Part (∆ E(t) ) [ΜV/m]

∆ff t ( ) ∆ ff jΘ t t j – ( ). j

∑

=

Feed Forward Real Part (∆ ff(t) ) [bits]

slide-43
SLIDE 43

JLAB, Nov. 2001 Stefan Simrock DESY

Reproducibility of Subsequent Pulses of Vector-Sum

800 850 900 90.35 90.4 90.45 90.5 90.55 90.6 time [us]

  • accel. voltage [MV]

10 consecutive rf pulses peak-to-peak: ± 0.03 MV

∆Vacc (rms) < 0.02 MV

800 850 900 950 24.3 24.35 24.4 24.45 24.5 time [us] phase [deg]

10 consecutive rf pulses peak-to-peak: ± 0.03 o

∆Φ(rms) < 0.02 o

Gradient Phase

slide-44
SLIDE 44

JLAB, Nov. 2001 Stefan Simrock DESY

System Identification (1)

smoothed Cavity-Field Forward-Power Beam-Current smoothed & derived smoothed Detuning during Pulse Beam-Phase Bandwidth

V ˙ ω1 2 ⁄ – ∆ω ∆ω ω1 2 ⁄ – V Rω1 2 ⁄ IG IB + ( ) + =

V ˙

ω1 2

⁄

– ∆ω ∆ω ω1 2

⁄

–

V Rω1 2

⁄

IG IB

+ ( ) + =

Differential Equation

slide-45
SLIDE 45

JLAB, Nov. 2001 Stefan Simrock DESY

5 10 15 20 25 20 40 60 80 100 120 140 160 180

No of Measurement beam phase/°

40˚ 50˚ 50˚ 60˚ 70˚

System Identification (2)

  • force Pf to be zero at

end of pulse by sub- straction of df*Pr (complex)

  • the whole shape

changes

Pr Pf

400 600 800 1000 1200 1400 1600 1800 2000 −150 −100 −50 50 100 150

time/µs ∆ f/Hz, ∆ f/Hz2, V2/2MV2 1st Order ID on Cavity 7

∆ω(t) Single Pulse Detuning Measurement Vacc Beam phase of 4 cavities for different phase of Vacc Correct for directivity

  • f couplers
slide-46
SLIDE 46

JLAB, Nov. 2001 Stefan Simrock DESY

Piezo-Actuator: Umax=150V l = 39 mm ∆l≈ 4 to 5 µm at 2K ∆fmax, static≈ 500Hz

Active Compensation of Lorentz Force Detuning (1)

He-tank + cavity

tuning mechanism

piezo

slide-47
SLIDE 47

JLAB, Nov. 2001 Stefan Simrock DESY

Active Compensation of Lorentz Force Detuning (2)

−200 −100 100 200 300 400

detuning [Hz]

500 1000 1500 2000

time [µs]

fill time 900 µs constant gradient

without compensation with compensation

“beam on”- time

9-cell cavity

  • perated at

23.5 MV/m Lorentz force compensated with fast piezoelectric tuner

slide-48
SLIDE 48

26/01/2004 Lutz Lilje DESY

RF signals at 35 MV/m

Blue: With piezo Red: Without piezo

slide-49
SLIDE 49

26/01/2004 Lutz Lilje DESY

NEW: Frequency stabilization at 35 MV/m

Blue: With piezo Red: Without piezo Frequency detuning of ~1000 Hz compensated with resonant excitation of a mechanical cavity resonance at 230 Hz. NOTE: This is rather an demonstration of the capability of active tuning. Application in a real machine is probably difficult/impossible.

slide-50
SLIDE 50

11th SRF Workshop, 2003 Stefan Simrock DESY

Integration of Piezo Tuner for TTF

slide-51
SLIDE 51

11th SRF Workshop, 2003 Stefan Simrock DESY

Measurement of Mechanical Preload

Force sensor Lifetime of piezo depends strongly

  • n mechanical preload. Optimum

around 1 kN/ cm^2. Piezo 1 Piezo 2 lifetime preload

1 kN/cm^2 2

(cycles) 1015 1010

3

slide-52
SLIDE 52

Characterization of the load cell Characterization of the load cell

A new insert was designed to host different load cells and the load generating device. Our goal is the characterization of the sensor at 4 K up to 2kN.

A load cell under test – from Burster

  • The button on the cell is pushed by

stainless steel rod, 20 mm diameter.

  • The loading force is generated by a

screwing device provided with washer springs at the top of the insert.

  • The loading force is measured by a

calibrated load cell placed in the cross junction, working at room temperature.

slide-53
SLIDE 53

Some results Some results

Up to now some 2kN load cells from Burster have been tested at 4K.

Now some points are clear:

  • High offset and low reproducibility are the

main critical problems

  • Linear range reduces and reproducibility

fails at cold => we’ll test cells with specific cryogenic features and higher RT range (10-15 kN)

The measured TF of two 8415 model and their beaviour vs time

T=300 K

y = 2.55E-05x - 3.89E-04 R2 = 1.00E+00 y = 2.38E-05x + 3.59E-05 R2 = 1.00E+00

  • 0.001

0.000 0.001 0.003 0.004 0.005 50 100 150 200 Kg V

8415-6002 s/n:185021 8415-6002 s/n:184992

T=4 K

y = 1.70E-05x + 1.32E-02 R2 = 9.62E-01 y = 1.84E-05x + 1.22E-02 R2 = 9.82E-01

0.0120 0.0133 0.0145 0.0158 0.0170 50 100 150 200 Kg V

8415-6002 s/n:185021 8415-6002 s/n:184992

slide-54
SLIDE 54

11th SRF Workshop, 2003 Stefan Simrock DESY

slide-55
SLIDE 55

New facility transfer functions New facility transfer functions

  • 70
  • 60
  • 50
  • 40
  • 30
  • 20
  • 10

500 1000 1500 2000 Hz dB Amplitude

The single copper cell system has been caractherized measuring the transfer function between the piezoelectric actuator voltage and the phase detuning of the cavity. Closed loop tests seem possible up to 2 kHz.

  • 600
  • 500
  • 400
  • 300
  • 200
  • 100

500 1000 1500 2000 Hz Deg Phase

slide-56
SLIDE 56

11th SRF Workshop, 2003 Stefan Simrock DESY

Microphonics Control

~ ~ ~

klystron cavity piezo actuator

LO RF Microphonics

Controller C(s)

IF

P(s) uc(s) yc(s) yp(s) up(s)

piezo sensor

slide-57
SLIDE 57

11th SRF Workshop, 2003 Stefan Simrock DESY

Controller Design

P(s) C(s)

frequency [kHz]

|D(s)|

1 10 Choose open loop response D(s)

C s ( ) D s ( ) P s ( )

  • =

⇒

D(s) : stability criteria fulfilled high gain at low freq. fast roll-off at high freq.

slide-58
SLIDE 58

11th SRF Workshop, 2003 Stefan Simrock DESY

Feedback Successfully Applied to QWR

  • C6701 processor from TI on PCI board (M67) with 4

ADCs and DACs (200kHz sampling rate)

  • Programmed state space equation for 20th order sys-

tem:

  • Latency only 20 µs for 20x20 matrix multiplication (C++)
  • Applied only notchfilter (672 Hz) and low pass (1kHz) to

control microphonics in QWR

xk

1 +

Axk Buk + = yk

1 +

Cxk

1 +

Duk

1 +

+ =

slide-59
SLIDE 59
slide-60
SLIDE 60
slide-61
SLIDE 61
slide-62
SLIDE 62
slide-63
SLIDE 63
slide-64
SLIDE 64
slide-65
SLIDE 65

MIT Optics & Quantum Electronics Group

Balanced Cross-Correlator

Output (650-1450nm)

Ti:sa Cr:fo

3mm Fused Silica

SFG SFG Rep.-Rate Control

(1/496nm = 1/833nm+1/1225nm).

Δt

0V

slide-66
SLIDE 66

MIT Optics & Quantum Electronics Group

Measuring the residual timing jitter

Output (650-1450nm) Jitter Analysis

SFG

Ti:sa Cr:fo

3mm Fused Silica

SFG SFG Rep.-Rate Control

(1/496nm = 1/833nm+1/1225nm).

GD

  • GD/2
slide-67
SLIDE 67

MIT Optics & Quantum Electronics Group

Measuring the residual timing jitter

Output (650-1450nm) Jitter Analysis

SFG

Ti:sa Cr:fo

3mm Fused Silica

SFG SFG Rep.-Rate Control

(1/496nm = 1/833nm+1/1225nm).

GD

  • GD/2
slide-68
SLIDE 68

MIT Optics & Quantum Electronics Group

Experimental result: Residual timing-jitter

The residual out-of-loop timing-jitter measured from 10mHz to 2.3 MHz is 0.3 fs (a tenth of an optical cycle)

1.0 0.8 0.6 0.4 0.2 0.0 Cross-Correlation Amplitude

  • 100

100 Time [fs]

100 80 60 40 20 Time [s] Timing jitter 0.30 fs (2.3MHz BW)

Long Term Drift Free

slide-69
SLIDE 69

MIT Optics & Quantum Electronics Group

Timing Stabilized Fiber Links (<1km)

Assuming no fiber length fluctuations faster than 2L/c.

Timing Stabilized Fiber Links (<1km)

Cross Correlator

Fiber Link

PZT Fixed Length L

532 nm Pump laser 10 fs Ti:sapphire laser

Two wavelength filter Dichroic Beam Splitter All Fiber Implementations at 1.5 µm with high repetition rates

slide-70
SLIDE 70

MIT Optics & Quantum Electronics Group

Self-balanced sub-10 fs RF- Synchronization

λopt/4 (2n+1) λRF/2

slide-71
SLIDE 71

MIT Optics & Quantum Electronics Group

Balanced Cross-Correlator

slide-72
SLIDE 72

MIT Optics & Quantum Electronics Group

slide-73
SLIDE 73

CASA Seminar 2/6/04 Stefan Simrock DESY

LLRF Subsystems/Components

  • RF phase reference
  • from main driveline
  • LO for downconverter
  • Timing System
  • Vector modulator
  • Downconverter
  • Digital Control (Fdbck + FF)
  • ADC, DSP, DAC
  • includes exception handling
  • Redundant simple feedforward
  • Redundant monitoring system
  • Transient detection
  • Interfaces to other subsystems
  • includes interlocks
  • Waveguide tuner and controls
  • Cavity resonance control
  • slow (motor) tuner
  • fast (piezo) tuner
  • CPU in VME crate
  • Network to local controls
  • Cabels and connectors
  • Power supply for electronics
  • Airconditioning in racks
  • Software
  • DSP (FPGA) code
  • server programs
  • client programs
  • LLRF Parameters
  • Finite State Machine
slide-74
SLIDE 74

Page 1

19 January 2004 8:46 pm /home/simrock/doc/frame/ttf_meeting/ttf_meet_jan_04/ref/llrf_team.fm

LLRF Team

Name Field of Expertise Ayvazyan, Valeri Software, FSM, DOOCS, Controls, Applications, Linac Operation Bienkowski, Andrej RF Hardware, analog and digital hardware Brandt, Alexander Finite state machine Bruns, Thomas Computer (Unix) administration Cichalewski, Wojciech Koseda, Boguslaw FSM and applications Czarski, Tomasz RF Modelling, FPGA development, optimal control Czuba, Krzysztof M.O. and Distribution, Fiber optic link Eints, Frank Hiwi Felber, Matthias Hiwi Froelich, Thomas Installation, Documentation, Maintenance Hensler, Olaf DOOCS control system (deputy of K. Rehlich) Grecki, Mariusz TUL-DMCS group leader Ignachin, Nikolai Sytov, Sergei Analog, digital, and rf electronics Jezynski, Tomasz FPGA control for RF Gun/XFEL Kierzkowski, FPGA hardware and programming Kotthaus, Daniel RF Gun Control Lilje, Lutz Piezo tuner, high gradient cavities Lorbeer, Bastian Master Oscillator and Distribution Makoswki, Dariusz Radiation issues for electronics Matsumoto, Toshiyushi RF System Modelling, LLRF Development Moeller, Guenter RF Hardware, Downconverter, vector-mod, rf-gate Pawlik, Pawel Single bunch transient Petrosyan, Gevorg DSP programming, DSP code and server Petrosyan, Lyudvig Timing expert, ADC server Posniak, Krzysztof FPGA hardware and software Pucyk, Piotr DOOCS control of FPGA Rehlich, Kay DOOCS control system (group leader) Romaniuk, Ryzard WUT-ISE group leader Rutkowksy, Peter DOOCS control of FPGA Rybka, Dominik Radiation damage to electronics Schrader, Matthias RF Control Sekalski, Przemyslaw Piezotuner and control Simrock, Stefan LLRF (group leader) Vetrov, Piotr DSP hardware (DSP board, Gigalink, ADC, DAC) Wagner, Richard Hera Protonen HF , NT Administration Weddig, Henning RF Hardware, M.O. and Distribution, Analog and digital electronics, RF Measurements Zabolotny, Wojciech FPGA hardware and programming

slide-75
SLIDE 75

CASA Seminar 2/6/04 Stefan Simrock DESY

Summary

  • Commissioning of LLRF for TTF II is well underway
  • Feedforward for ACC 4,5,6 (old IQ drivers) available
  • New C67 based DSP System for RF Gun and ACC1 under
  • commissioning. In operation with cavity simulator
  • New “field” detectors for RF Gun
  • Prototype of FPGA based controller and cavity simulator
  • Master oscillator and frequency distribution are

presently being installed

  • New frequencies (2856 MHz, 13.5 MHz)
  • Temperature stabilized coaxial distribution
  • Highly stable fiber optic monitoring system
  • Automation of LLRF operation under development