Double Beta Decay

1
Double Beta Decay

• ?????????

2
1.Double Beta Decay???

• 1-1.??
• 1-2.Majorana???
• 1-3.Double Beta Decay???
• 1-4.Double Beta Decay????????

3
1-1.??

• Neutrino-less?
• Double Beta Decay???
• ?????!

4
1-2.Majorana???

• Majorana?? Dirac??
• ????? ?? ???
• ???????? ?????
• Condition Condition
  
• ???? ????
  
• ???????????

5
1-3.DBD???

• mode(Standard Model)
• diagram

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1-3.DBD???

• Condition
• 1??ß???????????????

Energy
??
N(A,Z-2)
DBD
N(A,Z)
7
1-3.DBD???

• DBD???
• 1.beta decay beta decay
• 2.electron capture beta decay
• 3. electron capture electron capture

8
1-3.DBD???
mode( Neutrino-less ) diagram
9
1-3.DBD???

• Standard Model?????????
• 1.?????????
• ???????????
• 2.?????????
• ??????????

10
1-3.DBD???

• Neutrino-less Double Beta Decay???
• 1.Majorana??
• 2.??????helicity????
• Massive???????

11
1-4.Double beta decay????????

• Majorana?????
• ????????
• ?????????????

12
2.????????????????????????????

• 2-1.CdTe(????????)
• 2-2.??????
• 2-3.Coplanar grid technique
• 2-4.Flash Analog Digital Converter
• 2-5.????????
• 2-6.???????????
• 2-7.??????

13
2.????????????????????????????

• ?????CdTe???

??????????????????(Q?)
Q????????????????????????
14
2-1.CdTe(????????)
????

• ??????????????
• ????????????????
• ???????
• ????????????
• ???????????

?????
15
2-2.??????
??
???

• ???

???
???
????????????????????????????????????????
????????????????????????????
????????????????????????????
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2-3.Coplanar grid technique
????Grid
????Grid
????Grid
CdTe
?????

• ??????????2??Grid???????????Grid??????????

17
???????????????????
??1
??????
e
-
??2
??????
CdTe
???
???

• ??????????Grid?????

??2
Voltage
??1
Voltage
??????
??????
??
??
18
???????????????????
??1
??????
e
-
??2
??????
CdTe
???
???
??????????Grid?????
??2
Voltage
??1
Voltage
Voltage
-

??????
??????
??
??
??
????????????????????
???????????????????????????
19
???????

• Cs(????)????????CdTe????????????????????

CH1(high bias)
CH2(low bias)
CH2-CH1
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2-4.Flash Analog Digital Converter
??FADC?????
Voltage
???????ADC??
??
??????????????
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2-4. Analog Digital Converter
??FADC?????
Voltage
FADC??
??
?????????????????
22
2-5.????????
a52.2665 b1.32146 c14.6032 ???9.04911
a43.3118 b1.35264 c14.5578 ???9.29151
Cs(????)?????????
a35.8562 b1.62626 c14.2246 ??? 11.43272

• ????????

CH1????130V????????(b/c)???? c????????????
23
2-6.???????????
???
(511keV)
????????
(511keV)
????????????????

• CdTe(??????)????????
• 2??NaI??????????????

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CdTe?4??NaI???
4????2??NaI?????????????? CdTe????????????? ??????
????
25
2-7.??????
26
????

• 33??????????
• 10?????????????

27
????

• 10????neutrino-less double beta decay?
• 0????

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3.????(CdTe)

• Grid tech????
• hole?????????????
• Grid Tech?????????(?????)!

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3.????(CdTe)

• ??????????
• ?????????????????
• But CdTe???????????????
• ????????
• ??????????
• ????????
• Bias?????

30
3.????(DBD)

• Neutrino-less Double Beta Decay?????
• ???33????
• ???????????????

31

• Thank you for your listening!