MTA Activities and Plans

1
MTA Activities and Plans

• MCTF
• August 17, 2006
• A. Bross

2
MuCool Program

• 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

• Currently consists of 9 institutions from the US
  and Japan

RF Development ANL Fermilab IIT JLAB LBNL Mississi
ppi
Absorber RD Fermilab IIT KEK NIU Mississippi Osak
a
Solenoids LBNL Mississippi
3

• RD Focus of MuCool
• Component testing Fermilab
• RF Cavities
• High RF-power Testing
• Absorbers
• Technology tests
• High power-load testing
• With beam
• Magnets

4
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 _at_15 Hz
• 2.4 X 1014 p/s
• 600 W into 35 cm LH2 absorber _at_ 400 MeV
• RF power from Linac (201 and 805 MHz test stands)
• Waveguides pipe power to MTA

5
MTA Hall
6
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

7
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

Gradient in MV/m
Peak Magnetic Field in T at the Window
8
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

9
RF RD 201 MHz Cavity Design

• The 201 MHz Cavity is now operating
• Recently reached 16MV/m at B0 (design gradient!)

10
Absorber Design Issues

• 2D Transverse Cooling
• and
• Figure of merit MLRdEm/ds
• M2 (4D cooling) for different absorbers

H2 is clearly Best - Neglecting Engineering
Issues Windows, Safety
11
Convective Absorber Activities

• First Round of studies of the KEK absorber
  performed in the MTA
• GHe used to input power

12
Convective Absorber Activities II
13
Convective Absorber Activities III

• Next Round of tests will use a modified absorber
• Test
• Electrical Heater
• New Temperature sensors
• LH liquid level sensor

Instrumentation will be used in MICE
Absorber Body being modified in Lab 6 at Fermilab
14
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.

15
MTA recent activities

• Due to Tritium problem from Numi
• Our cooling water feed for the MTA hall was
  changed to Caseys 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

16
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 is Highest Priority!