HE Aug The balloon-bone CALET prototype detector(bCALET) S. Ozawa ， S. Torii ， K. Kasahara ， H. Murakami ， Y. Akaike Y. Ueyama ， D. Ito, M. Karube, K. Kondo, T. Niita(Waseda Univ.) T. Tamura (Kanagawa Univ.) Y. Katayose(Yokohama National Univ.) K. Yoshida Shibaura Institute of Tech. Y. Saito, H. Fuke (JAXA/ISAS) J. Kawada(Bern Univ.) On be half of bCALET Team

HE Aug CALET ~CALorimetric Electron Telescope~ Evaluation of the detector performance Verification of the observation capability The balloon-borne CALET prototype(bCALET) Calorimeter Gamma-ray Burst Monitor Star Tracker The side view of the calorimeter structure Calorimeter of CALET is composed of Charge Detector (CHD) ， Imaging Calorimeter （ IMC ） and Total Absorption Calorimeter. The CALET payload will be installed in the Japanese Experiment Module Exposed Facility (JEM-EF) of the International Space Station (ISS). We developed a balloon-borne payload to verify the CALET capability by carrying out precursor flights for the electron and gamma-ray observations. International Space Station JEM(Kibou)

HE Aug bCALET Detector bCALET-1(2006) bCALET-2(2009) IMC(SciFi) 1024ch (128mm x 128mm x 4XY) 4096ch (256mm x 256mmx 8XY) IMC(W)1.3 r.l.3.5r.l. TASC （ BGO ） 13.4 r.l.(4 logs x 6 layers ） 13.4 r.l. (10 logs x 6 layers) SΩ 21 cm 2 sr 320 cm 2 sr bCALET-1 IMC FEC TASC IMC TASC SIA Tungsten bCALET-2

HE Aug Imaging Calorimeter （ IMC ） Observation of the pre-shower stage Tracking of the incident particle Target (Tungsten) SciFi 1mm sq. Plastic Sci. S1 S2 64ch MaPMT SciFi belt (32 fibers x 2 layers) SciFi planes (X&Y) in IMC, coupled MaPMT and FEC （ bCALET-2 ） The Front End Circuit(FEC) FEC can read out 8 PMTs(512ch) bCALET-1bCALET-2 SciFi 128 fibers (4layers each x-y) =1028 Fibers ⇒ Readout (FEC) 512ch x 2 unit 256 fibers (8layers each x-y) =4096fibers ⇒ Readout(FEC) 512ch × 8unit Target (W) 0.10 r.l.×3layers 1.00 r.l.×1layer 0.43 r.l.×6layers 1.00 r.l.×1layer Radiation Length 1.3 r.l.3.5 r.l. IMC’s Structure

HE Aug Total Absorption Calorimeter （ TASC ） PIN-PD （ S ） 25mm Energy estimation Particle identification of e/p TASC-FEC （ bCALET-2 ） BGO The FEC has a wide dynamic range as ~10 4 by adopting charge sensitive amplifier and 2 kind of main amplifier with different ranges PMT read out of the 1 st layer in TASC （ bCALET-2 ）. These signals are input to OP-AMP for adding. Additional signal is sent to discriminator bCALET-1bCALET-2 BGO size 25mm×25mm×300mm Sensor PIN-PD （ 18mm×18mm ） Quantity 4 logs x 6 layers10 logs x 6 layers Readout PreAMP +Shaping AMP +PH-ADC Readout module (Charge Sensitive AMP+ Shaper+SH-ADC) Radiation length 13.4 r.l. TASC’s Structure Alternate layers are oriented 90 degrees to each other to provide an x, y coordinate for tracking the shower core BS

HE Aug Data Acquisition System (bCALET-2 ) Telemetry Sending event and HK data with PCM communication (64kbps) DAQ system Taking each detector data when trigger received Command Observation commands setting trigger mode, threshold level, etc. Operational commands Balloon control Trigger system Creating trigger signal by S1, S2, BS and ANTI BGOPMT 10ch Sum AMP DAC Trigger Generator S1 S2PMT Anti × 3PMT DATA BUS SciFi X, Y 2 layer IMC-FEC 64MAPMT×8 BGO TASC-FEC PD 4ch I/O board Scalar 2ch AMP PHADC Clock Generator 2ch I/O board ADC Master Controller PCM & Date Storage DIO CF 32GB PCM Transmitter Command Receiver HK Data Thermometer × 16 Pressure × 1 Power supply High Voltage BGOPMT 10ch Sum AMP DAC Trigger Generator S1 S2PMT Anti × 3PMT Master Controller IMC-FEC TASC-FEC 10ch Sum AMP I/O board Scalar 2ch AMP PHADC I/O board ADC S1 S2PMT CF 32GB HK Data Thermometer × 16 Pressure × 1 Power supply High Voltage PCM & Date Storage PCM Transmitter CF 32GB DAC Trigger Generator Master Controller DIO Command Receiver

HE Aug The balloon flight observation summary Level flight bCALET-1bCALET-2 Launch Date31, May, , Aug, 2009 PlaceSanriku balloon center (JAXA) Taiki Aerospace Research Field(JAXA) Level flight altitude 35~37km35km Duration 6 hours (37km level fright: 3.5hours) 4.5 hours (35km level flight: 2.5hours) Triggered event number The flight path of bCALET-1(left) and bCALET-2(right) Launch bCALET-2

HE Aug 2010 宇宙科学研究所： 01,Oct,2010 Observed Event ( Ｑ L Displayed ）： Electron candidate ＩＭＣ ADC Distribution ＴＡＳＣ ADC Distribution XY XY X Y High gainLow gain Electron Candidate The cascade shower starts from second layer in IMC and the lateral distribution of shower is narrow

HE Aug 2010 宇宙科学研究所： 01,Oct,2010 Observed Event (QL displayed) ： proton candidate ＩＭＣ ADC Distribution ＴＡＳＣ ADC Distribution XY XY X Y High gainLow gain Proton Candidate Single particle track is detected in IMC and shower start from TASC

HE Aug Observation results of bCALET Electron Gamma Analysis method and details of the result →Poster OG (T. Niita) These results of bCALET are compare with the former experiments (BETS) and simulation calculations assuming the flux of the primary particles The energy spectra are consistent with the BETS results and the simulations Atmospheric Primary electrons (Atmospheric gamma rays)

HE Aug Summary A series of balloon experiments with the CALET prototype detector (bCALET) was carried out for verification of the capability and evaluation of the performance The observed spectra of the electrons and the atmospheric gamma-rays were compatible with the former experiments and simulations These prototypes brought enough feedback for development of CALET in the operation proof of FEC for IMC and TASC, the evaluation of the observation capability Now we aim to the CALET mission

HE Aug CALET Presentations Oral –16 Aug, afternoon (Session 3) Overview of the CALET mission to the ISS (S. Torii) The science objectives for CALET (K. Yoshida) –17 Aug, afternoon (Session 2) The CALET Gamma-ray Burst monitor (CGBM) (K. Yamaoka) Poster (16-17 Aug) Capability of the CALET experiment for measuring elemental abundances of galactic cosmic ray heavier than Nickel (Z=28) (B. Rauch) Expected CALET Telescope Performance from Monte Carlo simulations (Y. Akaike) High- Dynamic range readout system using dual APD/PD for CALET- TASC (D. Ito) Performance of the CALET Prototype: CERN beam test (M. Karube) The event trigger system for CALET (Y. Ueyama) The CALET CHD for determination nuclear charge (Y. Shimizu )

HE Aug Thank You! 谢谢 !