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Korean Ultra High Energy Cosmic Ray School Array Experiment

Global Hands-On Universe 2007National Astronomical Observatory, Mitaka, Tokyo, Japan

2007. 7. 14

Ewha Womans University

Jongmann YangOn behalf of the COREA Collaboration

COREA Project Cosmic ray Research and Education Array in Korea

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Cosmic ray• What is cosmic ray?

– Fundamental particles, nucleus, extra terrestrial electro magnetic radiations

• Observed composition: – 50% proton, 25% alpha, 13% C/N/O nucleus, <1% electron, <0.1% gamma, heavy nucleus

• Discovery: 1912 Victor F. Hess (Austria), 1936 Nobel prize

인공위성 AMS, EUSO

풍선 CREAM

지상 AGASA, AUGER, COREA

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Cosmic Ray Ground Array Projects

• Array Projects– AGASA and HiRes: Previous– AUGER and TA: Current– Schools Arrays: Nebraska, LA, Italy, Seattle, Paris, Lisbon, Stockholm, London, etc <= GPS is routinely available since 2002

• Korean Strength (2840 junior high schools/ 1987 Senior high schools) Compact Geological Distribution of Schools High Speed Internet Network

Best Human Resources in Science

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California HIgh school Cosmic ray ObServatory

San Gabriel Valley

37 sites active

San Fernando Valley

33 sites active

NALTA

North American Large area Time coincidence Arrays

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Experimental Concept of COREA

Shower by atmospheric interaction

Ground Observation(COREA School Array)

Space Observation(MEMS satellite)

AGASA

COREA

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Three Goals of COREA Project

Basic Science Project Science Education in High

Schools

Popular Science ProjectParticipation of Many Students and General

Public

Ist Class Science Project &

Korean Technologies

Official Web Page http://www.corea-korea.orgCOREA (Cosmic ray Research and Education Array in Korea)

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Content of COREA Project

•Network of Surface Detectors at Nationwide High Schools– 1~2 Detector at Each School

Team of Students and a Teacher, Production, Operation, DAQ – System

(Detector + PM tube + Electronics + PC) + (Internet + GPS + S/W)

•First Korean R&E Model of Big Science - Uijeongbu Science High School supported by KOSEF (2006.5 – 2007.2)

PS

Elec

PC

GPS

PlasticScintillator

Back

Side

Front

Setup of Detector Stations Setup of Detector Stations

Three detector stations The total detection area: 6m2

Roof of Uijeongbu Science High School

③

④

①

②

Cosmic Ray

1010

Plastic Scintillation DetectorPlastic Scintillation Detector

Depth : 1 cm

Length : 100 cm

Width : 100 cm

22 fibers

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GPS Receiver

COREA Electronics

GPS Antenna

GPS Antenna Cable

Low voltage operation : 3 V High timing performance < 2ns VIC-100, Synergy Systems, USA  

GPS Antenna & ReceiverGPS Antenna & Receiver

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Data Acquisition ProgramData Acquisition Program

Trigger modes by FPGA

0 CH1 and CH2 and CH3 and CH41 CH1 and CH2 and CH3 or CH1 and

CH2and CH4 or CH1 and CH3 and CH4 or CH2 and CH3 and CH4

2 CH1 and CH2 and CH3 or CH1 and CH2 and CH4

3 CH1 and CH2 and CH34 CH1 and CH2 or CH1 and CH3 or CH1

and CH4 or CH2 and CH3 or CH2 and CH4 or CH3 and CH4

5 CH1 and CH2 or CH1 and CH3 or CH1 and CH4

6 CH1 and CH2 or CH1 and CH37 CH1 and CH28 CH1 or CH2 or CH3 or CH49 CH1 or CH2 or CH310 CH1 or CH211 CH1 only12 CH2 only13 CH3 only14 CH4 only

Event Data Example

7 * 256 + 214 = 2006 년 GPS Time Data

Year 7*256 + 214 = 2006

Month 12

Day 6

Time 18:34:17

Nanosecond 3*2563 + 34*2562 + 208*256 + 98

ADC Data gathered from four Detectors

column 2 Channel 1 Data

column 3 Channel 2 Data

column 4 Channel 3 Data

column 5 Channel 4 Data

Event DataEvent Data

1023

0

0 2 μsec

Waveform

Waveform of one event

10ns

Preliminary ExperimentPreliminary Experiment

The same particleTwo particles originated from one air shower

Vertical arrangement Horizontal arrangement

Confirmation of coincidence between two detectors in independent systems

Result & Analysis(1)Result & Analysis(1)

17,827 coincident(< 1 sec) events were recorded for 50 min by three detector stations.

17,827 events / 50 min

(6 events / sec)

Jan 15, 2007 20:00-20:50

Number

of events

0.5 sec maximum time difference (within 1 second)

1616

55 events

Number

of events

0.0125 sec

360 events

Enlarge 40 times

Figure 1

Figure 2

Result & Analysis(2)Result & Analysis(2)

55 events are piled up close to the origin.

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With 55 events clustered within 150 ns of time interval, and assuming that the signal is due to

a single high-energy cosmic ray, we estimate that the primary particle energy is around 1 TeV. The time differences of 100ns are caused by error of the oscillator in readout board.

Result & Analysis(3)Result & Analysis(3)

10-6 sec

Enlarge 12500 times

Number

of events 55 events

1 TeV cosmic rays

Figure 2

Figure 3

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DSC09457

One teacher and four students of Uijeongbu Science High School with

professors and students of Ewha Womans University Feb 2007

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SummarySummary

Three detector stations had been set up at Uijeongbu science high school, each detector station with four plastic scintillation detectors.

Coincidence signals were detected by three detector stations.

Install more detector stations at Ewha University and Yonsei University to detect higher energy cosmic rays .

Plan to construct large-scale ground array by distributing set of detector stations over high schools in Seoul and South Korea in the near future.

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COREA CollaborationJunior High ( 교사수 ) Senior High ( 교사수 ) Univ. ( 교수수 ) Others

강일 (1)고덕 (1)반송여중 (1)백양 (1)인수 (1)부천동여중 (1)

대구과학 (1)대연 (1)대전과학 (1)독산 (1)동국대부속 (1)민족사관 (2)안산 (1)인천대건 (1)인천숭덕여고 (1)제물포 (1)충남과학 (1)서라벌 (1)울산중앙 (1)의정부과학 ( 김기혁 )

전남대 (2)전북대 (2)충남대 (2)이화여대 (8)인하대 (2)경북대 (2)경상대 (3)경성대 (1)한양대 (1)부산대 (4)서울대 (6)서울시립대 (2)성균관대 (2)연세대 (3)중앙대 (1)

고등과학원 (1)한국천문연구원 (2)한국과학영재학교 (1)

계 6 개 학교 6 명 계 14 개 학교 15 명 계 15 개 학교 41 명 계 3 개 기관 3 명

Total 38 schools & Labs. 65 people

※ Students are not included in the statistics.