### Calculation of detector acceptance for measuring muon lifetime in

```Kuno-Group D1
Nguyen Duy Thong
CALCULATION OF DETECTOR ACCEPTANCE FOR
MEASURING MUON LIFETIME IN MUSIC BEAM
TEST BY GEANT4
OUTLINE
Introduction
 Results
 Summary

INTRODUCTION
MuSIC facility
The process in MuSIC facility:

At first, protons are accelerated in the MuSIC
facility.

Then, they will impact with a target to produce
p+ or p–.


m+, m– are emitted in p+, p– in the decay
process.
Last, particles will be detected by detector.
detector
target
proton
Particles (m+, m) are detected by a detector with
2 scintillators and 1 target.

The detector consists of
2 scintillators and 1
target.
2
scintillators have same
size 380x50x3.5 mm3
 Target is made of Mg.
The size of target:
370x80x20mm3
In this study, by using Geant4 simulation:
 First, without using dipole magneticfield(By=0T), the acceptance of detector is
determined.
 Using dipole magnetic-field (By = ±0.04T),
evaluate the acceptances of detector.
MOTIVATION
Evaluate efficiency of muon between beamline
and captured muon.
 Consider about detector acceptance. Detector
acceptance is defined as ratio between number
of detected e+ or e– and number of incident m+
or m–at detector.

RESULTS

For By=0T,

0.1mA-proton beam impacts with target, from
Geant4, some results were calculated
p＋
pー
Beamline
4949
1249
Sci 1
663
130
Sci 2
187
38
m＋
mー
e＋
10128
2024
0
1530
277
335
352
68
212
eー
0
335
329
The efficiency of m
eff m +
number of detect ed at Sci1m + 1530


 0.151 15.1%
+
number of beamlinem
10128
eff m 
number of detect ed at Sci1m 277


 0.1369 13.7%

number of beamlinem
2024

The detector acceptance
+
number
of
detect
ed
e at Sci1 and Sci2 335+ 212
Pm + e + ) 

 0.054  5.4%
+
number of beamlinem
10128
number of detected -eat Sci1 and Sci2 335+ 329
Pm e ) 

 0.328  32.8%

number of beamlinem
2024



For By=+0.04T
p＋
pー
Beamline
1957
1550
Sci 1
222
315
Sci 2
46
125
m＋
mー
e＋
eー
5461
2306
0
0
690
402
441
382
149
131
274
219
The efficiency of m
effm +
number of detected at Sci1m + 690


 0.1264 12.64%
+
number of beamlinem
5461
effm 
number of detected at Sci1m - 402


 0.1743 17.43%

number of beamlinem
2306

The detector acceptance
+
number
of
detect
ed
e at Sci1 and Sci2 441+ 274
Pm + e + ) 

 0.1309 13.09%
+
number of beamlinem
5461
number
of
detect
ed
eat Sci1 and Sci2 382+ 219
Pm  e  ) 

 0.2606 26.06%

number of beamlinem
2306

For By=–0.04T
p＋
pー
Beamline
7745
545
Sci 1
1232
57
Sci 2
400
10
m＋
mー
e＋
eー
13073
1248
0
0
2158
139
1269
709
564
26
847
363
The efficiency of m
eff m +
number of detect ed at Sci1m + 2158


 0.165  16.5%
+
number of beamlinem
13073
effm 
number of detected at Sci1m - 139


 0.1113 11.13%

number of beamlinem
1248

The detector acceptance
number of det ect ed +e at Sci1 and Sci2 1269+ 847
Pm e ) 

 0.1618 16.18%
number of beamlinem +
13073
+
+
number
of
det
ect
ed
eat Sci1 and Sci2 709+ 363
Pm  e  ) 

 0.859 85.9%

number of beamlinem
1248
SUMMARY
In this research, with 0.1mA-proton beam,
numbers of p+,p,m+,m,e+,eー were estimated
 The detector acceptances were calculated.

Next step
• Some features need to be improved to
ensure simulation better.
BACKUP
By = 0T
Beamline
Sci 1
Sci 2
663
Stop at
Sci1
44
187
Stop at
Sci2
34
p＋
4949
pー
m＋
mー
e＋
1249
10128
2024
0
130
1530
277
335
16
444
43
16
38
352
68
212
7
73
12
5
eー
0
335
0
329
0
By=+0.04 Beamline
T
Sci 1
Stop at
Sci 1
Sci 2
Stop at
Sci 2
p＋
1957
222
16
46
13
pー
1550
315
9
125
10
m＋
5461
690
188
149
36
mー
2306
402
50
131
11
e＋
0
441
4
274
3
eー
0
382
0
219
0
By=
ー0.04T
Beamline
Sci 1
Stop at
Sci1
Sci 2
Stop at
Sci 2
p＋
7745
1232
73
400
27
pー
545
57
4
10
1
m＋
13073
2158
496
564
90
mー
1248
139
34
26
2
e＋
0
1269
14
847
9
eー
0
709
0
363
0
```