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Beam direction and flux measured by MUMONK. Matsuoka (Kyoto)for the MUMON group
Contents:1. Beam stability (direction/flux)2. Absolute m beam flux
Neutrino beam direction
Measure (n) beam direction by measuring muon profile center. (Another end is target)1-mrad shift of the beam direction corresponds to 11.8-cm shift of the MUMON profile center.Requirement for MUMON:
3-cm=0.3mrad precision
2.5˚Beam dump
MUMON
295 kmTarget
Hornsp
p
nm
m118 m
OTR
Baffle
Basic Analysis methodanalysis has done by simple charge integration& 2D Gaussian fitting.for both online/offline analysis
PedestalGate
Silicon80 mV
for 3 x 1011 ppp
wave form x 49
in some analysis,we also use total charge of 49 ch
Confirmation of Horn focusing
3 horns, 320 kA (shot# 47577), 2.16 x 1012 ppb, 6 bunch
1st horn, 275 kA (shot# 47987), 2.10 x 1012 ppb, 6 bunch
no horn, 0 kA (shot# 48704), 2.13 x 1012 ppb, 6 bunch
peak sigma peak sigma1547 pC 83 cm 38.5 pC 90 cm467 pC 95 cm 13.2 pC
104 cm218 pC 110 cm 6.29 pC
126 cm
x2.1
x7.1
Stability of the beam direction
Monitored the profile center obtained by the 2D Gaussian fit. During continuous 425 shots (Run:
280136) With 3 horns operation at 320 kA. Proton beam intensity (CT05):
2.15 x 1012 ppb x 6 bunches
* 30-dB attenuators was used for the silicons.
Stability (fitted beam center)
Chamber x
RMS: 4.3 mmRMS: 3.0 mm
Silicon x
RMS: 1.9 mm RMS: 2.4 mm
Silicon y Chamber yCenter values are different by ~1cm.Need check!
(MUMON intrinsic fluctuation estimated by S/N is ***mm )
Stability (beam direction) (MUMON center)/(Dist.from target)
• No time dependent drift• Beam direction was tuned well within 1
mrad.Monitor alignment should be checked.Further turning in Jan.
Beam axis
√ (
x2 +
y2)
Stability (flux)incl. stability of beam+horn field+MUMON
Silicon Chamber
RMS/Mean: 0.8% RMS/Mean: 0.8%
Stability (flux) cont’d.CT normalized
Silicon Chamber
RMS/Mean: 0.5%RMS/Mean: 0.50%
0.5% is same as the CT stability by Shibata-sanstability of MUMON+(horn field) < 0.5%MUMON intrinsic fluctuation estimated by S/N is ***%
Stability (flux) incl. beam+horn field+MUMON
No time dependent drift
Beam scan on the targetOnly horn-off data in Nov/Dec commissioning(1st horn 273kA data in April/May
commissioning)
Scan w/ all horns will be in Jan/Feb. Opposite direction shift is expected.
x
target
Proton beam were intended to shift in parallel. But angle change also existed
Beam scan on the target- Center position-
•MUMON alignment?• Beam angle effect? (0.3mrad)• Target alignment?• SSEM18-19 alignment?
Beam scan on the target-Muon yield-
Total Charge Peak charge
Gap btw. Baffle and target?
P beam
f30mmf26mm
baffle
target
Target center may be at -0.5~-1mm??
Absolute muon flux estimation
Two methods in addition to the emulsion measurement A) Energy deposit calculation by MC.
Get the relation btw. muon flux and energy deposit in the detector
B) Calibration by electron beam testUnder study. Preliminary result is showing
consistent result w/ A)
Estimation from MC energy deposit
Energy deposit by all particles is summed up and divided by #muonsContrib. from d-rays generated outside detector and
escape of d-rays generated inside detector are (automatically) taken into account
Edep = 2420 MeV/(15266 muons) = 158.5 keV/muon
Ionization yield:Q = Edep / 3.6 eV x e0
= =7.045 x 10–3 pC/muon
2420 MeV
Energy deposition in the silicon (MC)
*Relying on estimation of d-ray contribution by Geant3.Bare Si measurement confirmed that the d-ray contribution is robust(~1% effect) against materials around.
Comparison w/ MC
Absolute muon beam flux
Silicon (chamber) measurement is consistent w/ emulsion one.
Muon flux measured by each detector at the center emulsion (104/cm2) • Correction of the z-
position diff. is applied.• Cuts for emulsion
analysis is applied (p > 0.05 GeV/c, q < 0.3 rad)
@ 3.7 x 1011 ppb
[ 3 horns 320 kA ]IC data/MC: 0.87
SummaryHorn focusing effectBeam direction Tuned within 1 mrad (and will be further
tuned.) Less than 0.03mrad (rms) fluctuation
Beam flux<0.5% (RMS) fluctuation
Target scanHorn-off data for target center determination
Need more study to understand the obtained results
Horn-on data will be taken in Jan./Feb.Absolute muon flux estimations and comparison w/ MC Agree with the emulsion measurement.
Supplement
Stability of the proton beam
Run: 280136Cont. 6-bunch operationInc. monitor stability Stability of CT: 0.5%
(Shibata-san’s talk)RMS: 0.1 mm
RMS: 0.2 mm
RMS/Mean: 0.9%
Uji electron beam test
6-coil CT Electronics calibration factor inc. AMP:
(4.053±0.004) x 10–3 pC/ADC Pedestal RMS: 17.9 (for 120 samples)
0.007 pC uncertainty
IC Electronics calibration factor:
(4.158±0.002) x 10–2 pC/ADC
Energy loss comparison (Uji/T2K)
Energy loss in the chamber (Ar + 2% N2, 131 kPa, 34˚C) by MC Uji 100-MeV electron beam: 4.042 keV/electron (av. of all
particles; g, e) T2K beam at the center: 4.755/4.824/4.443 keV/muon (1st horn
0/220/273 kA) 4.674 ± 0.231 keV/muon (av. of all particles; g, e, m)
Uji beam T2K beam
A-1. Chamber calibration
CT gain was calibrated by Suzuki-san 0.1555 ± 0.0001 (out/input charge)
IC/CT from the Uji electron beam testCorrection of energy loss diff. between the electron beam and the T2K muon beam (16%).
IC calibration factor:(4.80±0.25) x 103 muon/cm2/pC
IC/CT = 128.0±0.2
A-2. Silicon calibration
Si/IC ratio from high intensity beam data (horn off) --- 33.89±0.09
Correction of the z-position difference (8%) Beam density at each position is different due to
beam divergence.
Silicon calibration factor: 154±9 muon/cm2/pC
Absolute muon flux (chamber)
CT efficiency by calibration: 0.1555 ± 0.0001 CT factor: (4.019±0.003) x 107 particle/pCIC/CT (Uji): 128.0±0.2 (Ar + 2% N2, 130 kPa, 29.7˚C)
Uji IC factor: (3.140±0.006) x 105 electron/pC (3.120±0.006) x 105 electron/pC @ 131 kPa, 34˚C
Energy loss in MC (Ar + 2% N2, 131 kPa, 34˚C) Uji 100-MeV electron beam: 4.042 keV/electron (av. of all
particles; g, e) T2K beam at the center: 4.674±0.231 keV/muon (av. of all
particles; g, e, m)
T2K IC factor (“collected charge” to “muon flux” conversion): (2.70±0.14) x 105 muon/pC = (4.80±0.25) x 103 muon/cm2/pC
Absolute muon flux (silicon - Si/IC)
T2K IC factor: (4.80±0.25) x 103 muon/cm2/pCCharge ratio at the center Si/IC in data (run 280086, horn 0 kA): 33.89±0.09 (–15 dB Att. is not calibrated, assuming 0.1777)
Beam size: sx,ySi 128.8±0.1, 138.1±0.1, sx,y
IC 133.6±0.6, 155.4±0.4 cm
Muon flux ratio at the center of Si/IC plane in MC 1st horn 0 kA: 1.066±0.017sta (sx,y
Si 170±4, 166±4, sx,yIC 174±5, 177±5 cm)
1st horn 220 kA: 1.072±0.015sta (sx,ySi 157±3, 162±3, sx,y
IC 161±3, 182±5 cm)
1st horn 273 kA: 1.084±0.013sta (sx,ySi 128±2, 125±2, sx,y
IC 133±2, 139±2 cm)
1.084±0.018±0.013sta
Si factor: 4.80 x 103 / (33.89 / 1.084) = 154±9 muon/cm2/pC
Absolute muon flux (silicon - dE/dx)
MC estimation of energy deposit in the silicon plane at the center with 1st horn 273 kA:Eloss = 2.420 GeV/(15266 muon) = 158.5
keV/muon
Ionization yield:Q = Eloss / 3.6 eV x e0 = 7.045 x 10–3 pC/muon
Si factor: 141.9 muon/pC
Comparison between Si and emulsion
Muon flux ratio at the center of Si/emulsion plane in MC 1st horn 0 kA: 1.096±0.018sta (sx,y
Si 170±4, 166±4, sx,yIC 177±5, 183±5 cm)
1st horn 220 kA: 1.113±0.016sta (sx,ySi 157±3, 162±3, sx,y
IC 165±4, 188±5 cm)
1st horn 273 kA: 1.128±0.014sta (sx,ySi 128±2, 125±2, sx,y
IC 136±2, 145±2 cm)
1.128±0.032±0.014sta
Muon reduction rate at Si by the cut for the emulsion analysis (momentum > 0.05 GeV/c, angle < 0.3 rad) by MC 1st horn 0 kA: momentum cut 0.024%, angle cut 2.1% 1st horn 220 kA: momentum cut 0.026%, angle cut
3.4% 1st horn 273 kA: momentum cut 0.052%, angle cut
3.6±1.2sta % 3.65±1.5±1.2sta %
Absolute flux (summary table)
Silicon (Si/IC) Silicon (dE/dx) Emulsion jnubeam 10a
1st horn 0 kA 1.04±0.07 0.96 1.00±0.02 1.74±0.02
1st horn 220 kA
1.70±0.12 1.56 1.61±0.02 2.37±0.02
1st horn 273 kA
2.30±0.16 2.12 2.16±0.03 3.07±0.02
Muon flux measured by each detector at the center emulsion (104/cm2)
Silicon (Si/IC) Silicon (dE/dx) Emulsion
1st horn 0 kA 0.60 0.55 0.57
1st horn 220 kA
0.72 0.66 0.68
1st horn 273 kA
0.75 0.69 0.70
Muon flux ratio of each detector to MC