MEG Beam Line Studies

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MEG Beam Line Studies
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Outline of Topics to be Addressed

• Status at the time of the last Review
• Beam Time April/May 2003 Z-Branch
• Beam Transport Solenoid BTS
• Future
• Summary/Conclusions
• Beam Line Schedule
• Area Layout

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Status at the Last Review

• Milestone achieved on
  schedule
• Viable Solution for the MEG Beam Line FOUND
• using Z-Branch with separate stages
  for
• Particle Separation Momentum Degradation
• via 2 triplets WIEN Filter
  Solenoid/Degrader system
• Rudimentary work on Transport Solenoid BTS
• had just started
• initial length 180cm? with B0.5T?
• Warm or Cold? etc.
• Solenoid Degrader Stop Distribution
  measurements
• planned
• Final part Phase C of Z-Branch
  Measurements
• April/May
  2003

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Z-Branch Measurements April/May2003
Measurements Phase B post
Triplet 2 Collimator Phase C post
Solenoid Several unexpected problems encountered
Solved !!!
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April/May 2003 Beam Test cont.

• Total of 4 Weeks
• of Beam Time
• 1 week Phase B
• 3 weeks Phase C
• PROBLEMS
• 3 Days Accelerator Down
• Planned for
• Solenoid Fringe-field
• distorts optics between
• Triplet 2/Collimator Solenoid
• Extra vacuum pipe between Collimator Solenoid
  SOLVED !!!
• WIEN Filter DOWN for nearly ALL Phase C
  measurements
• due to HV-insulation Problems at Cable
  feed-through (OIL)
• Measurements done without Separator ? FULL e
  beam

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Results Z-Branch Measurements

Phase A
P-Spectra ?-Kinematic Edge (29.79
MeV/c) Theoretical func. P3.5 folded
with Gaussian ?P/P Const. Cloud µ contribution
U-Branch
Z-Branch Pcent(28.20.1)MeV/c ?P/P (7.90.6)
FWHM PBeam(28.20.9)MeV/c Consistent
with TURTLE P-Slit settings/Calib.
Integrated Rate 4cm Tg.E _at_ 1800µA Nµ1.3108
µ/s (2.3108 µ/s 6cm Tg.)
Z-Branch
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Phase B Separation Quality

Phase B
Integrated Rate After Separator 4cm Tg.E _at_
1800µA Nµ9.4107 µ/s (1.7108 µ/s 6cm
Tg.) Ne/Nµ gt 9 Ne 8.7108 e/s Transmission
Factors TSep (715) TColli (905)
Low Threshold 50mV
µ
e
Integrated Rate 4cm Tg.E _at_ 1800µA Nµ8.5107
µ/s (1.5108 µ/s 6cm Tg.)
µ/e Separation 11.8cm 7.2s !!!
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Phase C Post Solenoid

Remember !!! PSC only a Test Solenoid PSC-Solenoi
d 20cm Bore Beam Line 32 cm Bore
Integrated Rate After Solenoid 4cm Tg.E _at_
1800µA Nµ6.1107 µ/s (1.1108 µ/s 6cm
Tg.) Beam Spot sX 5.3 mm sY 6.5
mm Transmission Factor Solenoid TSol 71
Single Node SNM
Double Node DNM
Previous Excitation Curve DNM confirmed DNM
focus Z0 14.53 A Previous U-Branch
14.56 A
With larger Bore i.e. BTS Tgt71
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Degrader Stopping Distribution Measurements

Target Thickness vs. NaI Rate
Michel Range Curve using NaI
AIR
VAC
R 870 µ CH2
Degrader
Target
Target
88 stopped in 400µ CH2 Tg.
Measurement ? Simulation Fix Degrader 600 µ Geant
say 580µ Nearly all Stopped in 400µ
Gives RMean 1150µ Equiv GEANT TRIM 88 STOP
in 400µ Tg !!!
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Beam Transport Solenoid BTS

Design in conjunction with Novosibirsk PSI
Magnet Group Tokyo Superconducting solution
Chosen Present Design under study LCRYO 2800
mm LCOILS 2630 mm DBORE 320 mm BCENT 0.347
T Optics further simulations underway
COBRA
BTS
COBRA
BTS
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Future

• Priorities
• Finish simulations for design BTS ? end July
• Complete BTS Design together with Novosibirsk,
  PSI, Tokyo
• ? Manufacture Delivery by late Spring
  2004
• Start Design for new Triplet 1 Wagon Quads (µE4
  Beam)
• ? ready for Insertion Shutdown 2003/2004
• Start Design of Target System for Experiment
  choose optimal
• Degrader positioning
• Continue Data Analysis of Beam Data
• New vertical Separator requested ( MEG, µLAN,
  µSR)
• ? vertical WIEN Filter MANDATORY for MEG

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Summary/Conclusions

• Satisfactory Beam Line Solution has been achieved
  for MEG
• with a complete test of components up to COBRA
  injection
• Separator Transmission of (715) achieved
• Rate of 8.5107 µ/s at 1.8mA with 4cm Target at
  I/P Solenoid
• (1.5108 µ/s at 1.8mA 6cm Tg Proposal)
• µ/e Separation of 11.8cm at Collimator ? 7.2s
  achieved
• Using a small Bore Solenoid a Transmission of 71
  obtained
• rate 6.1107 µ/s at 1.8mA with 4cm Target
• (1.1108 µ/s at 1.8mA 6cm Tg PROPOSAL!!!)
• Spot-size post Solenoid of sX5.3mm, sY6.5mm
  achieved
• equivalent to spot-size in Proposal at Target
• 88 of ALL µ STOPPED in Thin Target of PROPOSAL

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Time Schedule Beam line
2002
2003
2004
2005
Studies
Solenoid BTS
Milestone Choice U/Z Method
Triplet 1
Target
Milestone
Test
Assembly
Design
Manufacture
2003
January
February
March
April
May
June
Shutdown
Beam Line Commission- ing starts
Insertion Triplet 1 COBRA installation
PMC Laser Hut Sindrum 2 removal
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?E5 Area Layout
Following Slides from Stefan Ritt
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Ideas for pE5 area

• Permanent installation of MEG experiment
• Concurrently run other experiments
• No need of rail system if
• Beam line elements are removed
• Concrete wall in front of MEG detector
• COBRA most electronics on platform
• LXe storage tanks on separate platform
• Calorimeter on small rail system
• 500 kg crane on top of platform
• curtain and A/C around platform

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Area Layout
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Platform Design
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Electronics
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Current design status (June 24th)