mctf 8/17/06 a. bross mta activities and plans mctf august 17, 2006 a. bross
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MCTF 8/17/06A. 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
MCTF 8/17/06A. 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
MCTF 8/17/06A. 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
MCTF 8/17/06A. 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
MCTF 8/17/06A. 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
MCTF 8/17/06A. 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
MCTF 8/17/06A. Bross
RF R&D – 201 MHz Cavity Design
The 201 MHz Cavity is now operating Recently reached 16MV/m at B=0 (design gradient!)
MCTF 8/17/06A. 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
MCTF 8/17/06A. Bross
Convective Absorber Activities
First Round of studies of the KEK absorber performed in the MTA
GHe used to input power
MCTF 8/17/06A. 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
MCTF 8/17/06A. 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.
MCTF 8/17/06A. Bross
MTA recent activities
Due to Tritium problem from Numi
Our cooling water feed for the MTA hall was changed to Casey’s pond
Introduced some problems that have now been remedied
LHe delivery system for magnet has been upgraded
Heat load now at spec 5T Solenoid has been re-trained
Now operates at spec Instrumentation Installed
Spark protection for 201 cavity Includes video camera and DVR
Scintillation counters Now have complete coverage for
805 and 201 systems Includes thin and thick Plastic
counters and NaI
MCTF 8/17/06A. Bross
Plans for the MTA
805 MHz RF studies (with and without B field) Long-term (1 week) conditioning at fixed gradient and 2.5T Be Window tests Materials tests Surface treatment
201 MHz RF test program B field tests
Conditioning to highest possible gradient (up 16MV/m) at max field available from magnet
Curved Be Windows Note: The 201 MHz power source from the Linac has been
offline since before the end of the shutdown Hope to have it available for our program in the next week or
two
Second round of tests with KEK LH2 convective absorber
201 MHz RF isHighest Priority!