Anticipated Muon RatesAnticipated Muon RatesRandom Information that might be Related Random Information that might be Related to the Anticipated Muon Ratesto the Anticipated Muon Rates

• Existing (ISIS-trip limited) measurements

• Comparison with new beamline

• Target test

• Conclusion

Existing MeasurementsExisting Measurements

Momentum Total rate/Hz

Fractions/%

p e

Rate Rate

130 8.2 0.0 25.5 67.7 6.8 2.1 5.6

160 11.3 0.0 61.7 28.9 9.4 7.0 3.3

175 17.3 0.0 77.5 16.6 5.9 13.4 2.9

200 25.4 0.0 75.0 18.7 6.3 19.1 4.7

230 12.4 0.0 81.7 13.3 4.9 10.1 1.6

265 19.0 0.0 87.6 5.1 7.3 16.6 1.0

280 355.9 0.0 100.0 355.9

300 2005.6 49.5 50.4 1010.8

350 2477.3 89.0 11.0 272.5

380 4083.3 95.7 4.3 175.6

400 5087.8 98.1 1.9 96.7

420 4047.4 98.6 1.4 56.7

450 99.5 0.5

500 4662.1 99.8 0.2 9.3

Existing MeasurementsExisting Measurements

ComparisonComparison

Q1 Horiz.

Q2 Vert.

ComparisonComparison

Q1 Horiz.

Q2 Vert.

Proton beamline, not muon

8” beampipe

Collection at 40o, not 25o

Production at 626MeV, not 800

50Hz………

TargetTarget

20.0

1.0

70.020.0

8.0

TargetTarget

2 ms

Target: 50 Hz + 150 Hz motion:

20 ms

Beam bump:

• ~1ms

• <650 MeV

Pion ProductionPion Production

626 MeV 800 MeV

LAHET LAHET (MCNP)(MCNP)

Factor ~30 increase at 430 MeV

~30k max. /s with old beamline in new position

Target TestTarget Test

• Presented previously

• Tough analysis

• Results not entirely obvious to interpret~2x109 protons

~1x1010 protons

~3x1011 protons

~7x1011 protons

Beamloss – c/o Dean AdamsBeamloss – c/o Dean Adams

• Beamloss: protection & diagnosis

• Currently from BLMs:Inhibit: 20 pulses > V in 10min - beam off for 1.5s

Trip: another inhibit within 10s – upset operators! MICE can inhibit, but can’t trip!

• “ “ BIMs:Immediate trip : 3 consecutive pulses exceed tolerance

Integration periodTolerance in protons per pulse

Trapping 0-2.5 ms 4.9E12

Acceleration 2.5-9.5 ms 2.0E12

Extraction 9.5-10 ms 1.0E12

MICE can’t do this

Average Trip: 25 pulse rolling average

Integration periodTolerance in protons per pulse

Trapping 0-2.5 ms 4.5E12

Acceleration 2.5-9.5 ms 0.5E12

Extraction 9.5-10 ms 0.5E12

MICE can do this with

~1013 in a single pulse

Beamloss – c/o Dean AdamsBeamloss – c/o Dean Adams

• From Christmas 07 from BLMs:Trip: 20 consecutive pulses > V

MICE can’t trip!

“The potential ability to take 1e13 proton without tripping is worrying. We may have to produce some trip derived on a single integrated blm measurement running on the MICE pulse. Changing the pulse counts to 1 would also be a solution but its effect on ISIS operation would require investigation.”

Target TestTarget Test

~2x109 protons

~1x1010 protons

~3x1011 protons

~7x1011 protons

0.2V ~1010 protons

BIM immediate trip

ConclusionConclusion

• To know real pion/muon rate: need another test

The BLM’s surrounding the MICE target in super period 7 have a tolerance level of 0.05 Vs under normal operation. The old HEP target , (50Hz operation) , tolerance levels were set to 0.2Vs. It is conceivable that > 0.2 Vs is satisfactory for MICE operation since the target operates at only 1 Hz. Suitable machine activation measurements should be performed to find an acceptable level.