Contents Performance What we have achieved

Contents

Performance

What we have achieved : Nextef

KT-1 : 50 MW X-band test station

We are operating two X-band high power stations

Klystrons

X-band klystrons

TD 18_Disk_#3 tested at SLAC TD 18_Disk_#2 tested at KEK Big difference in ramping speed. (may be partially due to the difference in processing procedure) Both reached 100 MV/m 240 ns.

Breakdown rate

TD 18_#2 all BDR versus Eacc It seems difficult to get a smooth curve as function of Eacc by collecting all data points scattered in time and in operation parameter space. Usually we get a smooth curve by measuring intentionally with focusing to take data of BDR vs Eacc!?

T 18_Disk_#2 BDR versus pulse width

Switching every second among three power levels, controlled by Ushimoto program.

Run 98 43 1 8 Higher power pulse makes bigger BDR. We compare this result to the usual BDR plot…

Data points from jumping among three levels

More than 50% of breakdowns are not accompanied by any consecutive breakdowns. Some are followed by breakdowns. Correlation between number of consecutive breakdowns and the hardness of the initial breakdown should be evaluated.

Demands for system upgrade

Nextef Pulse Compressor

Nextef pulse compressor Layout

Improvement Plan for KT-1

Power delivery from KT-1 to Shield-B We are able to start basic studies with structures using this test setup, though it sacrifices the usual KT-1 klystron activities (=Klystron test) somehow. This experimental activities should complement the series of high gradient tests on CLIC prototype structures proceeded at Nextef.

Status Components: More than 80% fabricated. A hole was made through a wall between KT 1 and shield-B. Installation of KT 1 -B in early next year. Pulse compression setup will follow KT 1 -B setup.

Nextef and KT-1 as of 2011

Summary: Future plans

Conlusions