Linear Alkyl Benzene (LAB) Cerenkov and Scintillation...

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 |

Outline

·Background and Mo>va>on ·Research Method

·Hardware System ·Offline Data Cut

·Result and Analysis ·Future Work Plan


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.


Hardware System -‐ Pla<orm

Top PMT

BoBom PMT

µ

LAB

Flash ADC

Op6cal fiber (Connect to PC)

Fig.1 PlaYorm


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


•  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


•  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.


Offline Data Analysis – Cut result

Fig.7 Landau fit of charge in 4

Coincidence channels.

•  Landau fit of Charge in 4 Coincidence channels


•  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


Fig.10 Add Top PMT signal and Bofom PMT signal from all good events (2033).

Result and Analysis

Bofom PMT

Top PMT


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!

Linear Alkyl Benzene (LAB) Cerenkov and Scintillation...

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