Electron Observation : Past, Present and Future

S.Torii : Waseda University (Japan)

Rome 　　　　　　　　　　　　 PAMELA Workshop　　　　　　　　　　　　　　 11.05.2009

Model Dependence of Nearby Source Effect

Ec=∞ 、 ΔT=0 yr, Do=2x1029 cm2/s at 1 TeV Do=5 x 1029 cm2/s

Ec= 20 TeV Ec=20 TeV 、 ΔT=1-104 yr

Kobayashi et al. ApJ 2003

We need a precise measurement at TeV energies to confirm the near-by sources for all of the models.

As a conclusion, we will wait for much more study by ATIC, PAMELA, FERMI-LAT, H.E.S.S.and a new experiment in space, AMS-02.

Moreover,we need accurate measurements up to 10 TeV for detection of nearby sources and ,naturally ,very-high-statistics observation for Dark Matter search in sub-TeV region with a detector which has performance:

The systematic errors including GF is less than a few %. The absolute energy resolution is less than 5 % ( ~ATIC). The exposure factor is as large as several 100 m2srday ( ~ FERMI-LAT). Possibly, the performance does not depend on energies.

It should be a dedicated detector for electron observation in space.

Calorimetric Electron Telescope (CALET) is proposed.

CALorimetric Electron Telescope

Dark Matter

Japanese Experiment Module (Kibo)

International Space Station

Cosmic Ray Sources

SNR

γ

γ

PairAnnihilation

PulsarAGN

γ e

P χ χ

e+

e-

CALET

A Dedicated Detector for Electron Observation in 1GeV – 10,000 GeV

International Collaboration Team

Waseda University ：　 S. Torii, K.Kasahara, S.Ozawa, S.Udo, N. Hasebe, M.Hareyama, N.Yamashita, 　　　 O.Okudara , S.KodairaJAXA/ISAS ：　 J. Nishimura, T. Yamagami , Y. Saito H. Fuke, M.Takayanagi, H. Tomida, S. Ueno, K.Ebis

awaKanagawa University ： 　 T. Tamura, N. Tateyama, K. Hibino, S.Okuno Aoyama Gakuin University ：　 A.Yoshida, T.Kobayashi, K.Yamaoka, T.Kotani Shibaura Institute of Technology ：　 K. Yoshida , A.Kubota, E.KamiokaICRR, University of Tokyo ：　　 Y.Shimizu, M.Takita, T.Yuda Yokohama National University ： 　 Y.Katayose, M.ShibataHirosaki University: S. Kuramata, M. Ichimura, T okyo Technology Inst.: T.Terasawa, Y. IchisadaNational Inst. of Radiological Sciences : Y. Uchihori, H. Kitamura Rikkyo University: H. Murakami Kanagawa University of Human Services : Y.Komori Saitama University: K.Mizutani Shinshu University : K.Munekata Nihon University: A.Shiomi

NASA/GSFC: J.W.Mitchell, A.J.Ericson, T.Hams, A. A.Moissev, J.F.Krizmanic, M.SasakiLouisiana State University: M. L. Cherry, T. G. Guzik, J. P. WefelWashington University in St Louis: W. R. Binns, M. H. Israel, H. S. KrawzczynskiUniversity of Denver: J.F.Ormes

University of Siena and INFN: P.S.Marrocchesi , M.G.Bagliesi, G.Bigongiari, A.Caldaroe, M.Y.Kim, R.Cesshi, P.Maestro, V.Millucci , R.Zei

University of Florence and INFN: O. Adriani,  P. Papini, L. Bonechi, E.VannucciniUniversity of Pisa and INFN: 　 C.Avanzini, T.Lotadze, A.Messineo, F.Morsani

Purple Mountain Observatory: 　 J. Chang, W. Gan, J. YangInstitute of High Energy Physics: Y.Ma, H.Wang,G.Chen

CALET Overview

CALET Mission Concept

Observation: Electrons in 1GeV - 20 TeV Gamma-rays in 20 MeV - 　 10TeV + Gamma-ray Bursts in 7 keV - 20MeV P-Fe in several 10GeV - 1000 TeV

Launch: HTV: H-IIB Transfer Vehicle

Attach Point on the ISS: Exposed Facility of Japanese Experiment Module (JEM-EF)

Life Time: 3(min.) - 5 years

Mission Status Phase A 　 for Launch around 2013 in Plan

CALET Payload High Energy Electron and Gamma- Ray Telescope Consisted of - Imaging Calorimeter - Total Absorption Calorimeter Weight: 1500 kg Geometrical Factor: ~0.7 m2sr Power Consumption: 640 W Data Rate: 300 kbps

JEM/EF

CALET

CALET launched by CALET launched by HTVHTV

CALET

HTV

HTV

ISS

Approach to Approach to ISSISS

Pickup of Pickup of CALETCALET

H-IIA Transfer VehicleH-IIA Transfer Vehicle （（ HTV)HTV)

Launching of H-II RocketLaunching of H-II Rocket Separation from Separation from H-IIH-II

Launching Procedure of CALET

CALET

SIA

IMC

TASC

SACS

Schematic Structure of the CALET Payload

GBM

MDP

VSC

GBM: Gamma-Ray Burst MonitorVSC: Visual Sky CameraMDP: Mission Data Processor

SACS:Scitillator Anti-Coincidence SystemSIA: Silicon Pixel ArrayIMC: Imaging CalorimeterTASC: Total Absorption Calorimeter

Scintillating Fibers(64 fibers = 1 unit)

Tungsten Prate+

Honeycomb Plate

Side Support Structure

1 Layer

Front End Processor Units

FEC +64 anode PMT

ATCS Coldplate

Scintillating Fibers(64 fibers = 1 unit)

Tungsten Prate+

Honeycomb Plate

Side Support Structure

1 Layer

Front End Processor Units

FEC +64 anode PMT

ATCS ColdplateBGO（12 ｘ6 ｘ2）

FEC

SUPPORT PANELS

CFRP BGO CASE

PDPMT

BGO（12 ｘ6 ｘ2）FEC

SUPPORT PANELS

CFRP BGO CASE

PDPMT

Details of Each Component

IMC TASC

SIA SACS(ACD)

Silicon Pixel Array x 2 layers ( Pixel ~1cmx 1cm) Charge resolution: 0.1e for p, 0.35e for Fe　　　

• Segmented Plastic Scintillators for Anti-Coincidence

Co-PI:Pier S. Marrocchesi

Examples of Simulation Events

Purposes of Electron　 Observation

Expected Electron Spectrum by the CALET Observation for 3 years(~ 1000 m2 sr day) 　

Cygnus Loop20,000 years2,500 ly

Monogem86,000 years1,000 ly

Vela 10,000 years820 ly

Chandra

ROSAT

・CALET

Vela

近傍ソースの検出-エネルギースペクトル-到来方向の異方性

超新星における衝撃波加速加速機構と拡散過程超新星の頻度、分布

太陽変調

Anisotropy

W=1048 erg/SNI(E)=I0E-α

Ｎ =1/30yrD=D0(E/TeV)0.3

Search for the signature of nearby HE electron sources (believed to be SNR) in the electron spectrum above ~ TeV

Search for anisotropy in HE electron flux as an effect of the nearby sources.

Precise measurement of electron spectrum above 10 GeV to define a model of accele-ration and propagation.

Observation of electron spectrum in 1~10 GeV for study of solar modulation

Possible Nearby Sources• T< 105 years• L< 1 kpc

Nearby Pulsars or Dark Matter

IMC

TASC>

(C) (A)

Geometry for Analysis

Energy Resolution

Geometrical Factor

Angular Resolution

CALET Performance by Simulation

i BGOlayerBGOlayer iEE 12FE =

RE = i BGOlayeri BGOlayeri iiEER

　　 Rejection Power for survival of 95 % electrons @ 4 TeV ~ 105 ( ~1 % residual protons) @100 GeV ~ 4x 105 ( ~ 0. 1 %)

1.27 M events of protons

4 TeV Electron 7.;8 TeV Proton

A little effect on electron flux by uncertainties in simulation model

Rejection Power against Background Protons

Detector Energy Region

(GeV)

Energy Resolution

e/p selection power

Key Instrument

(Thickness of CAL)

SΩT

（ m ２ srday)

PPB-BETS

(+BETS)

10 -1,000 13%

@100 GeV

4000

(> 10 GeV)

IMC

: (Lead: 9 X0 )

~0.42

ATIC1+2

(+ ATIC4)

10 -

a few 1,000

<3%

( >100 GeV)

~10,000 Thick Seg. CAL

(BGO: 22 X0)

+C Targets

3.08

PAMELA 1-700 5%

@200 GeV

105 Magnet+IMC

(W:16 X0)

~1.4

(2 years)

FERMI-LAT 20-1,000 5-20 %

(20-1000 GeV)

103-104

(20-1,000GeV)Energy dep. GF &

residual protons

Tracker+ACD

+Thin Seg. CAL

(W:1.5X0+CsI:8.6X0)

300@TeV

(1 year)

AMS* 1-1,000 ～ 2.5 ％＠ 100 GeV

104

(x 102 by TRD)

Magnet+IMC

+TRD+RICH

(Lead: 17Xo)

~100(?)

(1year)

CALET* 1-10,000 ~2%

(>100 GeV)

> 105 IMC+Thick Seg. CAL

(W: 4Xo+BGOr or PWO :27 Xo)

800

(3 years)

Electron(+Postron) Detector and Performance

*) Future Project