31.05.2005 Krzysztof Czuba 1

REFERENCE FREQUENCY DISTRIBUTION SYSTEM FOR THE

TESLA TECHNOLOGY BASED PROJECTS

Krzysztof CzubaMatthias Felber

31.05.2005 Krzysztof Czuba 2

OUTLINE

• Design requirements• System concept• System status• Future plans

31.05.2005 Krzysztof Czuba 3

DESIGN REQUIREMENTS

Synchronize RF devices along the accelerator with phase error << 1 ps

Distributed frequencies: 1.3GHz, 1MHz, 9MHz, 13.5MHz, 27MHz, 108MHz, 1517MHz, 2856MHz

Prototype system prepared in TTF2/UVFEL

31.05.2005 Krzysztof Czuba 4

SYSTEM CONCEPT

1.3GHz1.3GHz 1.3GHz1.3GHz 1.3GHz1.3GHz

Master

Oscillator

1st section

PLL

xM

PLL

xM

2nd section

PLL

xM

PLL

xM

N th section

PLL

xM

PLL

xM

N-1 phase stabilized fiber optic lines

PLL

xN

Master Oscillator

Fiber-optic long

distance links

Short coaxial cable sections

Stable local oscillators

31.05.2005 Krzysztof Czuba 5

MASTER OSCILLATOR - SYSTEM STATUS

• M.O. module ordered from a commercial company

• Many components provided to DESY• Phase stability tests in progress (B. Lorbeer)• Many components improved after first tests• Phase stable 1.3 GHz oscillators under

development: DRO and SAW investigated

31.05.2005 Krzysztof Czuba 6

COAXIAL CABLE DISTRIBUTION - STATUS

• Redundant, prototype cable layout installed in the TTF2

• Thermal insulation and heating tape assembled for cable temperature control

• Loss, length and cable reflections measurements performed

• Preliminary phase drifts measurements performed – phase drift between outputs of two 260m long cables ~1ps over 24h measurement

31.05.2005 Krzysztof Czuba 7

TTF2 PHASE REFERENCE DISTRIBUTION CABLE LAYOUT

31.05.2005 Krzysztof Czuba 8

FIBER OPTIC LINK

Phase stable signal distribution over long distances (up to 20 km)Feedback on phase suppressing long term drifts

Circulator

Long LinkSimulator

Mirror

RF Phase Detector

DFBLaserFO Tx

FO RxA

Phase Shifter

Controller

DirectionalCoupler

FO RxB

RFSignal in

RF Phase Detector

5 km of single mode fiber in temperature controlled oven

Temperaturevariation

Error voltage

Output phase check

Test - system block diagram

31.05.2005 Krzysztof Czuba 9

FIBER OPTIC LINK – STATUS

• Conceptual analysis performed• Prepared hardware and control software• Two versions of system tested – with spool

of fiber and motorized optical delay line as phase shifters

• Good results and experience achieved– Short term stability (minutes): ~0.8 ps (0.3 ps)– Long term stability (hours): ~4 ps (0.8 ps)

31.05.2005 Krzysztof Czuba 10

F.O. LINK V.1 - COMPONENTSFIRST SYSTEM TEST IN A CLIMATE CHAMBER

Temperature controlled oven

Laser transmitter System controller - GUIPhase detector

31.05.2005 Krzysztof Czuba 11

OPTICAL PHASE SHIFTERS5 km of fiber.

Easy obtainable phase shift of 3500o at 1.3 GHz

Problems with long lag time

10 cm optical length range

Phase shift of 160o at 1.3 GHz

4.7 fs phase change resolution!

Fast response

31.05.2005 Krzysztof Czuba 12

F.O. LINK V.2 COMPONENTS

31.05.2005 Krzysztof Czuba 13

F.O. LINK V.2 – MEASUREMENT RESULTS (CLIMATE CHAMBER)

Short term stability (minutes): ~0.3 ps

Long term stability (100 hours measurement duration): ~0.8 ps

31.05.2005 Krzysztof Czuba 14

F.O. LINK INSTALLED IN TTF2

31.05.2005 Krzysztof Czuba 15

FUTURE PLANS

• Finish F.O. system stability tests in the TTF2

• Tests of phase drifts of the fiber optic against coaxial cable distribution

• Development of controller for ODL and fiber spool connected in series for longer distribution distances

• Phase stable 1.3GHz oscillator development