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MICE RF Power

Paul DrummISIS Facility

Rutherford Appleton Laboratory&

MICE

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MICE

• Cost/Efficiency of the Neutrino Factory– Cannot be done without a demonstration of

ionisation cooling;– Essential for a muon collider– Accelerator aperture is a strong cost driver– Ionisation cooling reduces transverse beam

emittance

• MICE = Cooling Channel Demonstration

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The Neutrino Factory

e e +

Decay

Japan

Europe

USA

Factor of 10 in performance

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MICE

DetectorsSC-SolenoidCryogenic AbsorberRF -Cavities Diffuser

EU design study 44/88 MHz; US design study 201 MHzMICE Reproduces part of study II channel: 201 MHz

• to design, engineer, and build a section of cooling channel capable of giving the desired performance for a Neutrino Factory;• to place this apparatus in a muon beam and measure its performance in a variety of modes of operation and beam conditions.

Bz

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RF Module Overview

SC Coil

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Baseline specification

• 201 MHz• 8 cavities in 2 modules• Each cavity is isolated by Be windows

– In principle each cavity is independent (f,)

• Cavities operated in a magnetic field ~few T• 4 cavities replace energy lost in one absorber

– ~10 MV/m E~10 MeV

• >1 MW power per cavity• Pulse duty cycle ~ 1:1000 (1ms/1s)

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Solutions

• Cost estimate for MICE ~£3M for 8MW

• MICE Strategy:– 201 MHz typical on (old) linacs– ISIS, CERN, LBNL, Los Alamos, BNL, KEK!– 2x2MW amplifiers from LBNL (at DL)– 2x2MW amplifiers from CERN– 3x300kW amplifiers from LBNL– Power supplies promised by Los Alamos– Procure missing parts

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LBNL Circuits

TH170 amplifier

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4616 driver & test stand

Burle willing to refurbish/make 4th

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2 MW Amplifier

Master OscillatorControls etc

201 MHz Cavity Module

2 MW Amplifier

2 MW Amplifier

201 MHz Cavity Module

CERN300 kW Amplifier

300 kW Amplifier

300 kW Amplifier

300 kW Amplifier

HT Supplies

Los Alamos

HT Supplies

ASTeC

2 MW Amplifier

LBNL

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ISSUES for MICE R&D

• Old Tubes – Future supply uncertain– 116 ex ISIS– 170 ex CERN– 4616 still available

• Output power levels – limitations of circuits

• 8 Cavities fed from 4 amplifiers– Cavity interactions, reflected power, stability– Circulators– Hybrids

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MICE Tasks

• Refurbishing & Recommissioning existing kit• Procure missing items

– New– In house build– Beg, borrow (steal held in reserve)

• Aim to assemble at least one complete system as a test stand over next two FYs

• Future task – 4 power systems/8 cavities– MICE potential test bench for power sources

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Effect of Stong Magnetic Fields

RF dark currents were measured at Fermilab on 805 MHz cavities in magnetic field

Extrapolation to 201 MHz uncertain tests on 201 MHz prototype 2005 Environmental issue for MICE