Muon Accelerator R&D
description
Transcript of Muon Accelerator R&D
DOE Program Review 5/17/06A. Bross
Muon Accelerator R&D
DOE Program ReviewMay 17, 2006
A. Bross
DOE Program Review 5/17/06A. 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
DOE Program Review 5/17/06A. Bross
Design and Simulation
C. Johnstone, D. Neuffer, K. Paul, S. Poklonskiy K. Yonehara
DOE Program Review 5/17/06A. Bross
Overview
The International Scoping study of a Future Neutrino Factory and super-beam facility
Neutrino FactoryMuon Collider
FS2A Concept
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
Cooling simulation results
0
0.4m-0.4m
0.4m
0.5GeV
-50m
50m
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
MuCool
A. Bross, S. Geer, A. Moretti, B. Norris, Z. Qian
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
R&D Focus of MuCool Component testing Fermilab
RF Cavities– High RF-power Testing
Absorbers– Technology tests– High power-load testing
•With beam Magnets
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
MTA Hall
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
RF R&D – 201 MHz Cavity Design
The 201 MHz Cavity is now operating Recently reached 16MV/m at B=0 (design gradient!)
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
Convective Absorber Activities
First Round of studies of the KEK absorber performed in the MTA
GHe used to input power
DOE Program Review 5/17/06A. Bross
Convective Absorber Activities II
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
MICE
A. Bross, M. Ellis, S. Geer, A. Moretti, D. Neuffer, M. Popovic, R. Rucinski
DOE Program Review 5/17/06A. Bross
Muon Ionization Cooling Experiment
MICE
FocusCoils
CouplingCoils
LiquidHydrogenAbsorbers
RFCavities
Tracking Spectrometers
MatchingCoils
Beam Diffuser
Radiation shield
Magneticshield
DOE Program Review 5/17/06A. Bross
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.
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
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.
DOE Program Review 5/17/06A. Bross
MERIT
N. Mokhov, S. Striganov
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
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
DOE Program Review 5/17/06A. Bross
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!
DOE Program Review 5/17/06A. Bross
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