High Power RF Systems, Control and Distribution in the HINS Alfred Moretti, Brian Chase, Chris Jensen and Peter Prieto Fermilab Accelerator Advisory Committee May 10 th – 12 th, 2006

Fermilab 2 Outline Genera description of Fermilab High Intensity Neutrino Source (HINS) Linac Description of (HINS) linac R&D Study. Conclusions.

Fermilab MHz Klystron – Toshiba E3740 FERMI 115kV Pulse Transformer Modulator Capacitor / Switch / Bouncer Charging Supply RFQ MEBT RF Distribution Waveguide with Dir Couplers Ferrite Tuners Single Klystron Feeds RT and SCRF Linac to E > 90 MeV HINS 325 MHz Front END

Fermilab 4 M 325 MHz RF System Pulse Transformer & Oil Tank IGBT Switch & Bouncer CAP BANK 10 kV 110 kV Charging Supply 300kW MODULATOR: FNAL/TTF Reconfigurable for 1,2 or 3 msec beam pulse Single Fermi Klystron 325MHz 2.5 MW WR2300 Distribution Waveguide TOSHIBA E3740A IQMIQM E IQMIQM B IQMIQM T IQMIQM R F Q IQMIQM Cables to Tunnel Fast Ferrite Isolated I/Q Modulators RF Couplers S IQMIQM S IQMIQM R IQMIQM S IQMIQM S IQMIQM R IQMIQM 400kW 20 kW D IQMIQM S IQMIQM R IQMIQM D IQMIQM S IQMIQM R IQMIQM 120 kW 10kV H- Medium Energy Beam Transport Copper Cavities Radio Frequency Quadrupole RT Copper Single-Spoke Resonators Cryomodule #2 Double-Spoke Resonators 20 kW There will be more power distribution splits than shown

Fermilab 5 Simplified Layout of the RF Fan-out for 8 GeV HINS Linac This is simplified Layout of the high power RF distribution system The 325 MHz high power line is as shown except it will have 3 power splitter for Powering 3 directional coupler Arms and the RFQ. The 1300 MHz high power line because the base line klystron has two 5 MW power o utput Lines will have two 5 MW branches with several power splitters in each powering directional coupler arms. Directional Couplers Ding Sun’s Talk

Fermilab 6 Key: Klystron--, Hybrid--, Load--, Cavity-- Penetrations Linac Tunnel Linac Gallery One 325 MHz Klystron Driving 58 Cavities and RFQ H HH RFQ Rm temp Super C Super C

Fermilab 7 Status of Required Components Vendor quotes have been received for the required hybrid power splitters. Vendor quotes have been received for the string of directional couplers required to provide RF power to the cavities. In-house studies of directional coupler strings using HFSS is underway.

Fermilab 8 Directional Coupling Factors along the 325 MHz section of the HINS Linac The chart shows that the Superconducting cavity coupling factors remain constant with changes in beam loading (Blue and Yellow curves). The red and black curves show the coupling factor change with beam loading with beam loading changes.

Fermilab 9 HINS 325 MHz Klystron Toshiba E3740AFermi 325 MHz 2.5 MW Specification s: Beam V= 98 kV Beam I= 51 A Perveance=1.75uP Gain= 47 dB Efficiency=50 % Modulating Anode grounded to make a diode tube.

Fermilab MHz kltsron in Meson Building on its wheels.

Fermilab MHz Components Circulator Modern Photo-multiplier for Arc detection Miscellaneous required RF Components: Bends, Couplers, Bellows, straight pieces,etc.

Fermilab 12 LAYOUT OF Test and HINS Area LL RF Input Klystron Circulator Load Switch Waveguide components, bends, straights, couplers, etc., to Experimental test area Waveguide Components to HINS Area,

Fermilab 13 Bouncer Modulator Circuit

Fermilab 14 Bouncer Modulator Waveforms Switch connects main capacitor bank to transformer during pulse. Transformer steps up voltage to 120kV/130A (12:1) Main capacitor bank discharges by 20% during pulse “Bouncer” circuit compensates for cap bank droop. Main Capacitor and Bouncer Capacitor Voltage Klystron Voltage and Expanded Klystron Voltage

Fermilab 15 Pulse Transformer 4 ms Pulse Length for HINS

Fermilab 16 System Control Forward/Reflected Power Photo Detector Video Pulse Klystron Protection Interlock Boards

Fermilab 17 HINS and SMFT Interlocks

Fermilab 18 Conclusions All of the components for the 325 MHz klystron output RF power testing are on-hand. First RF power testing of 325 MHz klystron is scheduled for July of this year. Major Components of the modulator are on hand and testing of major assemblies is underway. Design of the of the equipment and safety interlocks has been completed. Construction and assembly and testing of the boards are underway. Conceptual design of the low level RF system has started in collaboration with LBL. Adaptations of In-house, Desy and SNS prototype control boards are under study.