Muon Accelerator R&D

DOE Program Review 5/17/06A. Bross

Muon Accelerator R&D

DOE Program ReviewMay 17, 2006

A. Bross


Muon Accelerator R&D

Our activities focus on studying the accelerator physics of a Neutrino Factory and Muon Collider and developing the accelerator technologies that are required to make these facilities a reality

This work is being conducted within the Framework of the US Neutrino Factory and Muon Collider Collaboration (NFMCC) and consists of

Design and Simulation Includes participation in international studies such as the

International Scoping Study for a Future Neutrino Factory and Super-Beam Facility (ISS)

MuCool MICE @ RAL Targetry – MERIT @ CERN

Approximately 7 FTE physicist effort


Design and Simulation

C. Johnstone, D. Neuffer, K. Paul, S. Poklonskiy K. Yonehara


Overview

The International Scoping study of a Future Neutrino Factory and super-beam facility

Neutrino FactoryMuon Collider

FS2A Concept


Design and Simulation -Some Specific Areas of Study

beam Drift Buncher

Rotator

Cooler

Overview of transport

Cool here

Capture/Bunch/Rotation/Cool

TimeTime

E

ner

gy

En

erg

yTwo fixed point acceleration: half synchrotron oscillation + path between fixed points

Linear nonscaling Linear nonscaling FFAGFFAG

H2 filled cavities


Capture/Bunch/Rot/Cool

0

0.005

0.01

0.015

0.02

0.025

100 120 140 160 180 200 220

Transverse emittance

Acceptance (per 24GeV p)

Change pressure to 150Atm Rf voltage to 24 MV/m Transverse rms emittance

cools 0.019 to ~0.008m

Acceptance ~0.22/p at εT

< 0.03m ~0.12/p at εT < 0.015m About equal to Study 2B

0

0.1

0.2

0.3

0.4

0.5

0.6

160 170 180 190 200 210 220

n0

e < 0.015

e < 0.030


Cooling simulation results

0

0.4m-0.4m

0.4m

0.5GeV

-50m

50m


Electron Model (EMMA)Host: Daresbury Laboratory U.K. downstream of their 8-35 MeV Energy Recovery Linac Prototype (ERLP) of the 4th Generation Light Source (4GLS

Unprecedented momentum compaction

Asynchronous gutter acceleration

Resonance CrossingEvolution of phase space

Validate concept for muon acceleration

Injection reference orbit

Extraction reference orbit

Proton Model (PAMILA)Provisional Patent: Fermilab

Host: Oxford University, U.K.

Tune-stabilized Nonscaling FFAG with no nonlinear fields

Strong + weak focusing machine

ApplicationsCarbon therapyProton driver

Injection reference orbit

Extraction reference orbit

FFAG Studies


MuCool

A. Bross, S. Geer, A. Moretti, B. Norris, Z. Qian


MuCool Program

Currently consists of 9 institutions from the US and Japan

RF DevelopmentANLFermilabIITJLABLBNLMississippi

Absorber R&DFermilabIITKEKNIUMississippiOsaka

SolenoidsLBNLMississippi

Mission Design, prototype and test all cooling channel components

(SFOFO) 201 MHz RF Cavities, absorbers, SC solenoids

Support MICE (cooling demonstration experiment) Perform high beam-power engineering test of cooling

section components


R&D Focus of MuCool Component testing Fermilab

RF Cavities– High RF-power Testing

Absorbers– Technology tests– High power-load testing

•With beam Magnets


MuCool Test Area

Facility to test all components of cooling channel (not a test of ionization cooling)

At high beam power Designed to accommodate full Linac Beam 1.6 X 1013

p/pulse @15 Hz – 2.4 X 1014 p/s

– 600 W into 35 cm LH2 absorber @ 400 MeV

RF power from Linac (201 and 805 MHz test stands)

Waveguides pipe power to MTA


MTA Hall


MTA

The MTA is the focus of our Activities

RF testing (805 and 201 MHz)

High pressure H2 gas-filled RF

LH2 Absorber tests

Two parts of infrastructure yet to be completed

Cryo Plant Beam Line


Phase I of RF Cavity Closed Cell Magnetic Field Studies (805 MHz)

Data seem to follow universal curve

Max stable gradient degrades quickly with B field

Sparking limits max gradient

Copper surfaces the problem

Gra

die

nt

in M

V/m

Peak Magnetic Field in T at the Window


Phase II of 805 MHz studies

Study breakdown and dark current characteristics as function of gradient and applied B field in Pillbox cavity

Curved Be window Test TiN coated Cavity has been

conditioned to 32MV/m without B field

Measurements at 2.5T– So Far – stable

gradient limited to about 14MV/m

Button test Evaluate various

materials and coatings Quick Change over


RF R&D – 201 MHz Cavity Design

The 201 MHz Cavity is now operating Recently reached 16MV/m at B=0 (design gradient!)


High Pressure H2 Filled Cavity WorkMuon’s Inc

High Pressure Test Cell Study breakdown

properties of materials in H2

Just finished run in B field No degradation in M.S.G.

up to 3.5T


2D Transverse Cooling

and

Figure of merit: M=LRdE/ds

M2 (4D cooling) for different absorbers

Absorber Design Issues

Absorber Accelerator

Momentum loss is opposite to motion, p, p x , p y , E decrease

Momentum gain is purely longitudinal

Large emittance

Small emittance

H2 is clearly Best -Neglecting Engineering

Issues Windows, Safety


Convective Absorber Activities

First Round of studies of the KEK absorber performed in the MTA

GHe used to input power


Convective Absorber Activities II


Convective Absorber Activities III

Next Round of tests will use a modified absorber

Test Electrical Heater New

Temperature sensors

LH liquid level sensor

Absorber Body being modified in Lab 6 at Fermilab

Instrumentation will be usedin MICE


LiH Test Program

Produce encapsulating cast (not pressed) samples Small disk (5-10 cm) for intense radiation

exposure Look at Material stability primarily Temperature Profile

Large disk (30 cm) for detailed thermal conductivity studies

External Cooling + Internal Heating Potential absorber for MICE Phase I

– Non-instrumented, no cooling


MICE

A. Bross, M. Ellis, S. Geer, A. Moretti, D. Neuffer, M. Popovic, R. Rucinski


Muon Ionization Cooling Experiment

MICE

FocusCoils

CouplingCoils

LiquidHydrogenAbsorbers

RFCavities

Tracking Spectrometers

MatchingCoils

Beam Diffuser

Radiation shield

Magneticshield


MICE – Precision Emittance Measurement

Expect 10% cooling (input 6π mm rad beam). Wish to measure this change to ~ 1%. Require measurement of emittance of beams into and

out of cooling channel to 0.1%! Cannot be done with conventional beam monitoring

devices. Instead, perform a single particle experiment:

High precision measurement of each track (position, momentum, time, energy).

Build up a virtual bunch offline. Analyse effect of cooling channel on many different

bunches. Study cooling channel parameters over a range of initial

beam momentum and emittance. Presence of X-rays and electrons from RF cavities and

safety issues relating to operation of LH2 absorbers affects specification of tracker.

Solution chosen – Scintillating Fibres readout with VLPCs.


Fermilab MICE Responsibilities

Scintillating Fibre Tracker:

Fibre Mirroring Ribbon fabrication Connector polishing

VLPC readout system: VLPC cassettes Cryostats (4) AFEIIt VLSB

Software: G4MICE DAQ / Controls and

Monitoring Tracker Quality

Assurance


MuCool and MICE

Muon Ionization Cooling Experiment (MICE) Demonstration of “Study II” cooling channel concept

Has Phase I UK funding ($20M)

MuCool Collaboration interface to MICE Design Optimization/develop of Study II cooling channel

Simulations Detailed engineering

Full component design Systems integration Safety

RF cavity development, fabrication, and test Absorber development, fabrication, and test Development of beam line instrumentation MuCool will prototype and test cooling hardware including

MICE pieces for which the collaboration is responsible Fermilab is also contributing to the cryogenics and readout

electronics for the two fiber trackers used in the spectrometers.


MERIT

N. Mokhov, S. Striganov


MERIT –Mercury Intense Target

Test of Hg-Jet target in magnetic field (15T) Submitted to CERN April, 2004 (approved April 2005) Located in TT2A tunnel to ISR, in nTOF beam line First beam ∼April, 2007

50 Hz operation at 2.2 GeV 4 MW


Fermilab Contribution to MERIT

Developed Full Mars Simulation

Particle fluxes, energy deposition, absorbed dose and residual activity in the experimental hall

Absorbed dose and activation of mercury system

Secondary particle production

Study/define diagnostics needed for experiment

Radiation load in components

Radiation shielding Particle production in

secondary beam


Plans for the Remainder of the Year

Design and Simulation Continue with participation in the International Scoping

Study (NF) NF Front-end detailed simulation

MuCool After a long pause due to the loss of our 805 MHz RF test

facility in Lab G at Fermilab, we are now up and running again

805 MHz RF studies (with and without B field)– Be Window tests– Materials tests– Surface treatment

201 MHz RF test program off to a Rousing start! – B field tests– Curved Be Windows

Second round of tests with KEK LH2 convective absorber Prototype and test encapsulated LiH absorbers

RFHighest Priority!


Plans for the Remainder of the Year II

MICE Need to have trackers ready to commission at

Rutherford Lab in April 2007. Purchase fibre and perform mirroring. Produce ribbons (3 trackers = 45 ribbons ~ 70k fibres). Produce and commission 2-cassette cryostats.

MERIT Mars Simulations

Calculate radiation levels in secondary tunnels in order to determine the survivability of electronics

Develop final plan for instrumentation to measure particle fluxes

– Scintillation Counters– Cerenkov

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