Forschungszentrum Jülich In der Helmholtz-Gemeinschaft Rolf Stassen IKP/ COSY 08.12.2006 Darmstadt 1 Status report HESR 1: RF Cavity

Forschungszentrum JülichIn der Helmholtz-Gemeinschaft

Rolf StassenIKP/ COSY

08.12.2006Darmstadt

1

Status report HESR 1: RF Cavity

ecool

17,25m

Dipole magnetQuadrupole magnetSextupole magnetSolenoidspacer for skew quadspacer for snake solenoidinjection equipment

direction of antiprotons

APR

CSR

from RESR (from SIS18)PANDA

0 50m HESRRF1 RF2

K3 K2 K1

P1 P2

(P3)

vert

ical

hori z

onta

l

long

itudi

nal

(longitudinal)



08.12.2006Darmstadt

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Personal

• Dr. Alexander Schnase left FZJ – JAERI/J-PARC

(Japan)

• We could win over Dr. Sorin Papureanu to

reactivate the old tube amplifier (3-4 Month at

beginning of 2007)



08.12.2006Darmstadt

3

objectives

• low loss injection scheme and adequate

acceleration/deceleration structure for the

HESR

• Barrier bucket to compensate mean energy

lost together with stochastic cooling (->

HESR3)



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• 2 prototype cavities designed and under construction

• 1 RF accelerating Cavity (1,5 – 15 GeV/c, high power) with FineMety FT-3M cores

• 1 barrier bucket (lower power, high bandwidth) filled with VitroPerm F500

• All FineMety cores delivered (main costs: 100k€)

• Extensive tests required

• Additional 1kW broadband amplifier needed for barrier bucket cavity

Hardware status



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Barrier bucket cavity



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RF Tests for HESR at COSY

Signal synthesis to generate barrier bucket stimulation signal

Known barrier bucket signal(single sinus, 10*f0)

Measurement of gap-voltage

Calculation of transfer-function(fourier series, 20 harmonics)

Determination of modifiedstimulation signal



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Pre-distorted Arbitrary Waveform Generator Signal

AWG-signal

Gap-voltage

Beam-phase-monitor

Gap-voltage

COSY InjectionFrequency ~ HESR Revolution frequency



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First barrier bucket beam in COSY

AWG-signal

Beam-phase-monitorcapacitive probe: field of operation?

Gap-voltage



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Higher energies (f0 = 1.56 MHz)

At higher energies no compensatedBarrier bucket signal possible due to Bandwidth limitation of amplifier

Using the USE-Kicker as barrier Bucket cavity



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Next RF Tests for HESR at COSY

• Barrier bucket together with stochastic cooling

to compensate the mean energy lost

• Signalgeneration for USE-Kicker

• Compensation of mean energy lost

• Additional longitudinal stochastic cooling



08.12.2006Darmstadt

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Schedule

• 2nd annual report: signal synthesis, design of cavities

• COSY shutdown dec-jan 2006/2007: preparing the USE-Kicker for barrier bucket tests in COSY with stochastic cooling

• Feb-June: Reactivating the (20kW) Tube-amplifier (S. Papureanu)

• FineMety tests within the cavities during 2007

• Final report end 2007

Thanks for your attention

Documents

Forschungszentrum Jülich In der Helmholtz-Gemeinschaft Rolf Stassen IKP/ COSY 08.12.2006 Darmstadt 1 Status report HESR 1: RF Cavity