Transcript MuCool Status and Plans - International Muon Ionization

MuCool Overview
Muon Cooling R&D
NFMCC Meeting
March 12, 2006
A. Bross
NFMCC Meeting 3/12/06
A. Bross
MuCool
 Mission
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Design, prototype and test all cooling channel components
 201 MHz RF Cavities, LH2 absorbers, SC solenoids
Support MICE (cooling demonstration experiment)
Perform high beam-power engineering test of cooling section
components
Consists of 9 institutions from the US and Japan
RF Development
Absorber R&D
ANL
Fermilab
IIT
JLAB
LBNL
Mississippi
Fermilab
IIT
KEK
NIU
Mississippi
Osaka
Solenoids
LBNL
Mississippi
NFMCC Meeting 3/12/06
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MuCool
 R&D Focus of MuCool

Component testing Fermilab

High Power
– Both RF and Beam
NFMCC Meeting 3/12/06
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MuCool Test Area

Facility to test all components of cooling
channel (not a test of ionization cooling)
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At high beam power
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Designed to accommodate full Linac Beam
1.6 X 1013 p/pulse @15 Hz
–
–
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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
NFMCC Meeting 3/12/06
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MTA Hall
NFMCC Meeting 3/12/06
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MTA

The MTA is the focus of our
Activities
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RF testing (805 and 201
MHz)
Installation/commissioning of
Cryo-Infrastructure
High pressure H2 gas-filled
RF
LH2 Absorber tests
High Intensity Beam

Will start with low intensity
NFMCC Meeting 3/12/06
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MTA Cryo-Infrastruture
Compressor Installation and
piping are complete
Heat exchanger
Towards
Experimental Hall
Compressor Room
Needed for
Magnet Operations
and
LH2 Absorber Tests
• Two 400 HP 2-stage oil injected screw compressors
Refrigerator Room
• Tevatron satellite refrigerator to be operated on 5 K mode and 14 K mode (3” DE, 3” WE)
• Helium and nitrogen Dewar
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MTA Cryo Infrastructure
 Our goal was to have Cryo Plant Operational by NOW
 Needed signficant support from AD and PPD Cryo Groups
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AD – Wet engine installation/Controls/Commissioning
PPD – Transfer line system
But there was a problem
 Due to resource allocation to ILC cryo work, completing the
MTA Cryo by end of March did not happen

Negotiations with the Lab are in progess
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Start installation effort again in earnest after shutdown cryo work is
completed
New goal is to be operational late Fall
Running off 500L LHe dewars will cost the collaboration
approximately $3-4k/week of magnet operation

Expensive! – Working to optimize system for most efficient use of LHe
NFMCC Meeting 3/12/06
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MTA High Intensity Beam
MTA
 400 MeV beamline for the MTA
has been designed
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Under Craig Moore/Carol
Johnstone
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Developed Engineering Design
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Linac Area and Beamline
Shielding Assessment for MTA
The current beam line design
allows for Linac diagnostic
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Cost
Schedule
Safety Analysis

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External Beams Department
High-Quality emittance
measurement
Our goal is to bring Low Intensity
to the MTA as soon as possible
NFMCC Meeting 3/12/06
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Proceeding with the MTA Beam Line

Cost Estimate: $388k (including 30% contingency)
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Low-Intensity initial phase
Resources: $100k from Muon Collaboration
Requests
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PPD
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Pulsed Extraction Magnets: $75k in FY06 M&S (not likely at present)
Magnet stand fab
AD – SWF for installation
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Internal AD review November 30th. The response from the committee was
positive, but they asked a number of questions. A response to these questions
has been prepared has submitted.
Review Committee’s final report:
–
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It was agreed that the basic design philosophy is sound, and that the diagnostic
section will be of great use not only to the MTA, but to the general Linac operation as
well. Assuming that the items in the above list are addressed, and that doing so
identifies no new issues, then the committee can fully support the MTA beam line
design.
Modifications in Linac area have just been completed

Isolates future MTA beam line work from Linac operations
NFMCC Meeting 3/12/06
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MTA – Near Term Test Program

805 MHz Pill Box preparation complete
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Low power testing and conditioning begins
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3/06
Major Milestone has been reached
LH2 Absorber test
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1/1/06
TiN coated curved Be windows tests
Various B field configurations
201 MHz cavity testing begun
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Currently have reached approximately 1MV/m
805 MHz high-power testing begins
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11/30/05
Summer 06
Second phase of testing with KEK convective
absorber
This is dependent on new safety review
NFMCC Meeting 3/12/06
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RF Cavity R and D
ANL/FNAL/IIT/LBNL/UMiss
NFMCC Meeting 3/12/06
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Fundamental Focus Of RF R&D

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Study the limits on Accelerating
Gradient in NCRF cavities in
magnetic field
However

We believe that the behavior of
RF systems in general can be
accurately described (predicted)
by


Tensile strength of the
material(s) used in the cavity
fabrication (T)
Local surface field
enhancements (beq)
Esurf = (2T/eo)/beq

This applies to all accelerating
structures

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In SC structures local heating
becomes problem first
Follows universal curve
NFMCC Meeting 3/12/06
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Phase I of RF Cavity Closed Cell Magnetic
Field Studies (805 MHz)

Data seem to follow universal
curve
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Sparking limits max gradient
Copper surfaces the problem
Gradient in MV/m
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Max stable gradient
degrades quickly with B field
Peak Magnetic Field in T at the Window
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Phase II of 805 MHz studies
 Study breakdown and dark
current characteristics as
function of gradient and
applied B field in Pillbox
cavity
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Curved Be window Test
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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
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Evaluate various
materials and coatings
Quick Change over
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RF R&D – 201 MHz Cavity Design
 The 201 MHz Cavity is now operating
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Recently reached 16MV/m at B=0! (design gradient)
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Local Electrode Atom Probe (LEAP) Tomography

Atom probe experiments in collaboration with Northwestern U.

High Gradient material studies relevant to both NCRF and SCRF – ILC,
Neutrino Factory, Muon Collider, CLIC.
Prof. David Seidman Jason Sebastian (Northwestern),
P. Bauer, C. Boffo (FNAL), J. Norem (ANL)
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Surface microstructure
Surface contamination (oxides etc.)
Breakdown and Dark Currents
Data from these tests expand our knowledge of breakdown phenomena,
will allow us to develop a detailed model of the physics of breakdown in
cavities, and can provide a guide for materials/fabrication procedures for
RF cavities
Modeling Fracture
Atom Probe Data from Nb sample @ ~10 GV/m
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High Pressure H2 Filled Cavity Work
Muon’s Inc
 High Pressure Test Cell
 Study breakdown properties
of materials in H2
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In B field next
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Absorber R and D
IIT/KEK/NIU/Osaka/UMiss
NFMCC Meeting 3/12/06
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Absorber Design Issues
 2D Transverse Cooling
and
 Figure of merit: M=LRdEm/ds
Small emittance
Large
emittance
Absorber
M2 (4D cooling) for different absorbers
Accelerator
Momentum loss is
opposite to motion,
p, px, p y, E decrease
Momentum gain
is purely longitudinal
H2 is clearly Best Neglecting Engineering Issues
Windows, Safety
NFMCC Meeting 3/12/06
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Absorber Design Issues
 Design Criteria
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High Power Handling
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Study II – few 100 W to 1
KW with “upgraded” (4MW)
proton driver
10 KW in ring cooler
– Must remove heat
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Safety issues regarding use
of LH2 (or gaseous H2)

Window design paramount
– H2 containment
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Proximity to RF adds
constraints (ignition source)
Two Design Approaches
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Convective Cooling
– Shown to the right

Forced flow
– High power handling
H2 implies engineering complexity
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Convective Absorber Activities
 First Round of studies of
the KEK absorber
performed in the MTA
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GHe used to input
power
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Convective Absorber Activities II
NFMCC Meeting 3/12/06
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Convective Absorber Activities III
 Next Round of tests
will use a modified
absorber
 Test
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Electrical Heater
New Temperature
sensors
LH liquid level
sensor
Absorber Body being modified in Lab 6 at Fermilab
NFMCC Meeting 3/12/06
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Forced-Flow Absorber

Heat removed with external heat exchanger
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LH2 pumped from absorber to heat exchanger
Nozzles in flow path establish turbulent flow
Simulation via 2D and 3D FEA
Preliminary engineering design for implementation in the MTA
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Have taken possession of cooling loop & heat exchanger from SAMPLE experiment @
Bates/MIT
Prototype Absorber manifold has been fabricated
NFMCC Meeting 3/12/06
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MuCool Plans for the Coming Year
 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
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805 MHz RF studies (with and without B field)
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Be Window tests
Materials tests
Surface treatment
Use information from LEAP studies
201 MHz RF test program off to a Rousing start!
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B field tests
Curved Be Windows
RF
Highest Priority!
 Second round of tests with KEK convective absorber
 IIT ME thesis student to work on flow-absorber simulation and
test
 Complete MTA cryo infrastructure installation and commission
system
 Continue installation of 400 MeV beam line from Linac to the
extent that resources allow

Have the capability for low-intensity experiments
NFMCC Meeting 3/12/06
A. Bross
The MuCool Test Area Potential
 The MuCooL Test Area is becoming a
tremendous resource
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It has the potential to provide a Unique (Worldwide) R&D facility
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Multi-frequency RF test capability (NC and SC)
Hydrogen Safety
– Absorbers
– Gas-filled RF cavities
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Cryo-infrastructure (LN, high capacity LHe)
High-Intensity beam
NFMCC Meeting 3/12/06
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