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Linear Alkyl Benzene (LAB) Cerenkov and Scintillation Separation Mohan Li, Zhe Wang Tsinghua University June 05, 2015
Linear Alkyl Benzene (LAB) Cerenkov and Scintillation Separation
Mohan Li, Zhe Wang Tsinghua University
June 05, 2015
Mohan Li | LAB Cerenkov and Scin>lla>on Separa>on | 06.05.2015 | Page 2
Outline
·Background and Mo>va>on ·Research Method
·Hardware System ·Offline Data Cut
·Result and Analysis ·Future Work Plan
Mohan Li | LAB Cerenkov and Scin>lla>on Separa>on | 06.05.2015 | Page 3
Background and Mo2va2on
• China Jinping Underground Laboratory (CJPL) Neutrino Experiment will use the Cerenkov-‐Scin6lla6on detector. • Water-‐based liquid scin>llator (WBLS) might be the
detec>ng material. • We built a plaYorm for tes>ng the light characteris>c of Linear Alkyl Benzene(LAB), the raw material of WBLS. • It is the first prototype of the new detector. • It could measure the overlapping Cerenkov-‐Scin>lla>on
signal.
Mohan Li | LAB Cerenkov and Scin>lla>on Separa>on | 06.05.2015 | Page 4
Hardware System -‐ Pla<orm
Top PMT
BoBom PMT
µ
LAB
Flash ADC
Op6cal fiber (Connect to PC)
Fig.1 PlaYorm
Mohan Li | LAB Cerenkov and Scin>lla>on Separa>on | 06.05.2015 | Page 5
Hardware System – Structure of the Detector
• Trigger signal – A single ver6cal cosmic µ
Fig.2 Structure of the Detector
4 Coincidence Channels
2 An>coincidence Channels
Mohan Li | LAB Cerenkov and Scin>lla>on Separa>on | 06.05.2015 | Page 6
• Data sample • 4863 events in total. • Event rate is approximately 90/hour.
• Data cut -‐ Coincidence • Cut Peak/Width [V/ns] and Peak/Charge [Ohm/ns].
Offline Data Analysis – Cut in 4 Coincidence Channels
Fig.5 Peak/Charge v.s. Charge Fig.4 Peak/Width v.s. Charge
Cut Cut
Fig.3 An example of an event
Peak Charge (Square) Width(FWHM)
Trigger Time
Trigger Range (40ns)
4 Coincidence channels
2 An>coincidence channels
Top PMT
Bofom PMT
Mohan Li | LAB Cerenkov and Scin>lla>on Separa>on | 06.05.2015 | Page 7
• Data Cut -‐ An>coincidence • Cut Charge Integral [V×ns] in Trigger Range.
Offline Data Analysis – Cut in 2 An2coincidence Channels
Fig.6 Charge distribu>on in 2 an>coincidence channels
Cut Cut
• All the cuts are checked by looking at many events. • Cut result
• 2033 events (41.8%) pass the cuts.
Mohan Li | LAB Cerenkov and Scin>lla>on Separa>on | 06.05.2015 | Page 8
Offline Data Analysis – Cut result
Fig.7 Landau fit of charge in 4
Coincidence channels.
• Landau fit of Charge in 4 Coincidence channels
Mohan Li | LAB Cerenkov and Scin>lla>on Separa>on | 06.05.2015 | Page 9
• Trigger >me correc>on • Let different events have the same Trigger Time.
Fig.8 Add Bofom PMT signals from 22 events into one histogram directly.
Fig.9 The same adding aker Trigger Time correc>on.
Offline Data Analysis – Trigger 2me Correc2on
Mohan Li | LAB Cerenkov and Scin>lla>on Separa>on | 06.05.2015 | Page 10
Fig.10 Add Top PMT signal and Bofom PMT signal from all good events (2033).
Result and Analysis
Bofom PMT
Top PMT
Mohan Li | LAB Cerenkov and Scin>lla>on Separa>on | 06.05.2015 | Page 11
Future Work Plan
• Modify the structure of the liquid box to let PMT7 receive the UV scin>lla>on light.
• Check the reason of the jifer structure and eliminate it.
Ns
NC
gamma
electron
Fig.11 Schema>c diagram of the light yield curve.
• Measure the light yield of Cerenkov light and calculate that of Scin>lla>on light. Draw the light yield curve of of gamma and electron, which could: • Help to discriminate gamma from
electron. • Guide the formula of light sample.
Example: Same Scin>lla>on light, different Cerenkov light
Thank you!
