signal electron is single mono energetic delayed The - - PowerPoint PPT Presentation

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signal electron is single mono energetic delayed The - - PowerPoint PPT Presentation

Nov 23, 2022 6 likes •166 views

Proton - Production high-P low-P BG e - e - Signal - Spectrometer Magnet -e Conversion Muonic Atom Formation in-flight Production Secondary Beamline Target signal electron is

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SLIDE 1
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SLIDE 2

Proton Production Target Secondary Beamline

① π－ Production ② in-flight π－→ μ－ ③ Muonic Atom Formation ④ μ-e Conversion

Magnet Spectrometer π- μ- e- e- low-P BG high-P Signal

① ② ③ ④

Start with Carbon target

  • Lifetime of muonic atom ~ 2 μs
  • Energy of electron from -e conversion = 105 MeV
  • Single event sensitivity (1 year = 2×10% sec)
  • 1×10&'(
  • 2.5×10&'+ (4 years)

signal electron is…

  • single
  • mono energetic
  • delayed

The signal electron is identified by their momentum and time information In case of SiC…

  • 2×10&'+
  • 5×10&', (4years)
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SLIDE 3

Proton Beam

μ-e conversion searching experiment at J-PARC MLF H-Line

Experimental groups are working to complete H-Line with the facility group.

MLF Muon facility H1: DeeMe experimental hall

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SLIDE 4
  • Decay In Orbit

0.015 (event/year)

  • Distinguished by momentum
  • prompt background <2.9×10'( (event/year)

(zero in principle)

  • Distinguished by time distribution
  • Delayed protons from main pulse are

monitored by a beam loss monitor in RCS

  • Cosmic-ray induced

e: <0.018, ): <0.001 (event/year)

  • suppressed by duty factor(= 1/20000)

and horizontal tracking direction

  • Anti-Proton

Zero in principle

  • beam energy(=3 GeV)

< * p production threshold

Primary Proton from RCS

e- signals at detector

//

Measurement time window

//

Delayed proton Prompt electrons from delayed proton No proton

Momentum (MeV/c) 90 95 100 105 110 115 120 Counts (/0.2MeV/c)

  • 4

10

  • 3

10

  • 2

10

  • 1

10 1 10

2

10

Delayed proton DIO )-e conversion signal region

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SLIDE 5

Publication: PTEP, Volume 2017, Issue 2, 023C01

ON Anode wire: 1450V Potential wire: 0V Gas gain: O(104) OFF Anode wire: 1450V Potential wire: 1450V Gas gain: O(1)

efficiency ~98% in switching-ON period

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SLIDE 6

Watanabe spectrum

Beamtime had been held in MLF D-line

  • Performance test of spectrometer system
  • DAQ test with 4 MWPCs
  • Development of tracking analysis codes with real data
  • DIO spectrum analysis
  • Confirmation of Czarnecki C spectrum
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SLIDE 7

AMJ

  • -A=
  • 4AA=RH
  • 9=CAM
  • CDMHAQMMMDAA=PHP
  • ()T=HT=C=HLMMA==QL=H

=CHAM=QL

  • JAMAMA
  • 0FF45LAM=HLAMAHHC=CHAM
  • 9CCA=H/,
  • 9CCAB/,LRHDHSAPMDMD=MB=AFA=MMCCAAAAR(L
  • =ABAAR D41S0F=LD,/

Beam axis

Magnet axis

  • 25,430/FHA
  • 1FHAP=LHM==F=FA
  • 4A=LAAHMAHACR))4A
  • 9DAAJAHAHAH=HALAAH=M))4A
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SLIDE 8

1. test pulse 2. HV-switching OFF->ON 3.

  • ver shoot by PZC circuit

4. signal 5. HV-switching ON->OFF

#ch@X #ch@Y time (10ns) time (10ns)

A template waveform is a set of most frequent value in each sample points

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SLIDE 9

Momentum spectra of data are consistent to that

  • f MC

Calibrated with MC spectrum

Michel spectrum (calculation)

GeV

0.03 0.035 0.04 0.045 0.05 0.055 0.06 0.065 0.07 0.075 0.08

20 40 60 80 100 120

compared the shape of measured momentum spectrum with MC simulation

GeV

0.03 0.035 0.04 0.045 0.05 0.055 0.06 0.065 0.07 0.075 0.08

5 10 15 20 25 30 MeV

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SLIDE 10

MWPC laser

1 2

!" !"

When !" = 0.1 '' the errors of each MWPC are WC0: 0.35 mm WC1: 0.22 mm WC2: 0.19 mm WC3: 0.31 mm

Magnet axis

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SLIDE 11

(Momentum spectrum with moved MWPC) (Momentum spectrum with original position)

GeV/c cm

fitting with liner function in 40~50MeV/c region 9 : = < : − 0.045 + C

a(dx)

cm cm

b(dx)

a(dx) and b(dx) fitting with liner function Iteration for MWPC 1-4

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SLIDE 12

Calculate pdf of a in possible dx region

a

Calculate momentum distribution of

  • > the systematic error is smaller than statistical error

@mu+ 45 MeV/c)

  • GeV/c

at 50MeV/c relative statistical error=14% relative systematic error=1.4%

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SLIDE 13

DIO Momentum spectrum

DIO momentum spectrum can be calculated as (Measured DIO momentum spectrum) / (acceptance curve) Acceptance curve is generated by MC simulation with flat momentum gun file

acceptance curve @ 55MeV/c

Measured momentum spectrum @55 MeV/c

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SLIDE 14

MeV/c 48 50 52 54 56 58 60 0.1 0.2 0.3 0.4 0.5

MLF 201706 run6355-6419 MC Watanabe-O MC Watanabe-C (Uesaka-C) MC Czarnecki-C

DIO spectrum

normalizing region

  • Each spectrum normalized in the

normalizing region

  • The measured spectrum and each MC

spectrum are compared in the comparison region

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SLIDE 15

MeV/c 48 50 52 54 56 58 60 0.1 0.2 0.3 0.4 0.5

MLF 201706 run6355-6419 MC Watanabe-O MC Watanabe-C (Uesaka-C) MC Czarnecki-C

DIO spectrum

fit measured spectrum with each MC spectrum Watanabe-O : prob. = 21.5% Czarnecki-C : prob. = 92.9% Watanabe-C : prob. = 43.7%

normalizing region comparison region

  • Each spectrum normalized in the

normalizing region

  • The measured spectrum and each MC

spectrum are compared in the comparison region

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SLIDE 16