RF SystemsWG2 Main Linac

S. Choroba

RF System Layout

2 Talks on RF System Layout

Choroba, DESY: TESLA RF System Baseline

Tantawi, SLAC: Comments on the RF System for ILC

Tesla RF System Baseline S.Choroba

•572 RF Stations •36 Cavities per Station•10MW Multibeam Klystrons in Tunnel•Bouncer Type Modulator installed in Access Halls•Pulse Cables connecting Modulator and Pulse transformer•Linear Waveguide RF Distribution System with Circulators

Comments on the RF System for the ILC

Tantawi, SLAC

=> no circulators

=> 20000 magnetronsThese ideas have already been discussed within the TESLACollaboration before: e.g. the use of 20000 IOTs (magnetrons probably too noisy). But might be worthwhile to investigate them again

RF Sources10MW MBKs from 3 vendors are available

Thales CPI Toshiba

RF Sources cont.Sheetbeam Klystron proposed by Sprehn, SLAC

Interesting also for the XFEL

Modulators•Bouncer Modulator is state of the art for 1.7ms, 10Hz, 120kV•Several units have been build and are in operation•Subunits are made by industry

Modulators cont.

Modulator Design Issues, Jensen FNAL

•Bouncer Modulators developed, built and operated by FNAL (well known and proven design)•Proposed ideas to improve the bouncer modulator (control, switch, capacitors etc., some of these are already at VUVFEL modulators)•Other modulators should be investigated: e.g.SNS type, Thomcast modulator, Bouncer with multiple klystrons, Marx bank modulator, Series Switch modulator and mismatched PFN

Modulators cont.Jensen, FNAL

RF Distribution

Baseline: linear distribution with circulators

Hybrid C oupl er RF Distributi on

Cryomodule 1 Cryomodule 2 Cryomodule 3

RF from Kl ystron

cavity i nput coupler

waveguide transformer

hybrid coupler

circulator load

DETAIL

RF Distribution cont.Alternative Distribution without circulators, Tantawi, SLAC

•Similar ideas have been developed before at DESY•Sami Tantawi will come to DESY to discuss these and similar ideas

RF Distribution cont.

Other waveguide components discussed by Sami Tantawi:

•Active window•Ferrite Tuner

LLRF

LLRF cont.R. Pasquinelli. Low Level and High Level Support for the ILC

How will the RF System for the ILC look? My guess

•Overall layout should be reconsidered•RF system will probably use Klystrons•Modulators probably: Bouncer, Series Switch, or SNS•RF Distribution: Waveguide (linear or treelike) with circulators•LLRF: Digital System