HEAD2010 1March 3, 2010

The Future Prospects for Electron Measurements, the Frontier above 1 TeV

Shoji ToriiWaseda University

HEAD2010 2March 3, 2010

Electron & Positron Observation

Evolution of the UniverseDark Matter Origin

水素、ヘリウム４%

暗黒エネルギー暗黒エネルギー暗黒物質暗黒物質

重元素0.03%

ニュートリノ0.3%

星0.５%

暗黒物質25%

暗黒エネルギー暗黒エネルギー暗黒物質暗黒物質

重元素0.03%

ニュートリノ0.3%

星0.５%

暗黒物質25%

暗黒エネルギー70%

宇宙の質量構成比宇宙の質量構成比

水素、ヘリウム４%

水素、ヘリウム４%

暗黒エネルギー暗黒エネルギー暗黒物質暗黒物質

重元素0.03%

ニュートリノ0.3%

星0.５%

暗黒物質25%

暗黒エネルギー暗黒エネルギー暗黒物質暗黒物質

Heavy Element0.03%

Neutrino0.3%

Star0.5%

Dark Matter2 ３ %

Dark Energy7 ３ %

Constitutes of the Universe

Hydrogen 、Helium４%

( ) ⅰ 　 Monoenergetic: Direct Production of e+e- pair（ⅱ）　 Uniform ： Production via Intermediate

Particles（ⅲ）　 Double Peak ： Production by Dipole

Distribution via Intermediate Particles

Production Spectrum

⇒Mχ

Annihilation of Dark Matter （ WIMP)χχ→e+,e-

Production Spectrum（ Power Law Distribution ＋ Cutoff ）

Shock Wave Acceleration in SNR Acceleration in PWN

Astrophysical Origin

⇒

dN/dE E-2exp(-E/Ec)

Log(E)

Log(

dN/d

E)

Ec

↑

Propagation in the Galaxy• 　 Diffusion Process• 　 Energy Loss 　　 　　 dE/dt =-bE2

（ Syncrotron ＋ Inverse Compton ）

⇒

⇒

• 　 +/- or K+/- +/- e+/-

e++e-

HEAD2010 3March 3, 2010

220

3 2 3

1 2

1

, ~ 2

diffd dee

diff

diff e e

qf bt e

d

d t D t

16 1 1

1 328 2 1

~ 10 GeV s

~ 5.8 10 cm s 14GeV

-

ee

b

D

e± Propagation

2 2, , , ,e e e ee

f t x D f b f q t xt

For a single burst with

Atoyan 95, Shen 70Kobayashi 03

eq

cut ~ 1bt

Power law spectrum

DiffusionEnergy loss byIC & synchro.

Injection

← B/C ratio

(F0: E3 x Flux at 3TeV)

March 3, 2010 HEAD2010 4

A Naïve Result from Propagation T (age) = 2.5 X 105 X (1 TeV/E) yr R (distance) = 600 X (1 TeV/E)1/2 pc

1 TeV Electron Source: Age < a few105 years very young comparing to ~107 year at low energies Distance < 1 kpc nearby source

Source (SNR) Candidates : Vela Cygnus Loop Monogem

Unobserved Sources?

GALPROP/Credit S.Swordy

1 GeV Electrons 100 TeV Electrons

HEAD2010 5March 3, 2010

Model Dependence of Energy Spectrum and Nearby Source Effect

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

Ec= 20 TeV Ec=20 TeV 、 ΔT=1-104 yr

Kobayashi et al. ApJ (2004)

HEAD2010 6March 3, 2010

We are waiting for much more study by ATIC, PAMELA, Fermi-LAT, HESSand a forthcoming experiment in space, AMS-02.

Moreover,We need an accurate and very-high-statistics observation for searching Dark Matter and/or Nearby Pulsars in the sub-TeV to the trans-TeV region with a detector which has following performance:

The systematic errors including GF is less than a few %. The absolute energy resolution is as small as a few % ( ~ATIC). The exposure factor is as large as more than 100 m2srday ( ~ FERMI-LAT). The proton rejection power is comparable to 105 , and does not depend

largely on energies .

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

Calorimetric Electron Telescope (CALET) is proposed.

Efforts by the new experiments for deriving the positron and electron spectra are really appreciated to open a door to new era in astroparticle physics.

HEAD2010 7March 3, 2010

CALET Overview Observation: Electrons : 1-10,000 GeV Gamma-rays : 10-10,000 GeV (GRB

>100MeV) + Gamma-ray Bursts : 7 keV-20 MeV Protons, Heavy Nuclei: several 10 GeV- 1000 TeV ( per particle) Solar Particles and Modulated Particles in Solar System: 1-10 GeV (Electrons)

Instrument: High Energy Electron and Gamma- Ray Telescope Consisted of : - Imaging Calorimeter (Particle ID, Direction) Total Thickness of Tungsten (W) ：　 3 X0

Layer Number of Scifi Belts ： 8 Layers ×2(X,Y)

- Total Absorption Calorimeter (Energy Measurement, Particle ID) PWO 　 20mm ｘ 20mm ｘ 320mm　 Total Depth of PWO ： 27 X0 (24cm)

- Silicon Pixel Array (Charge Measurement up in Z=1-35) Silicon Pixel 11.25mmx11.25mmx0.5mm 2 Layers with a coverage of 540x540 cm2

SIA 120

TASC

TASC-FEC PD

IMC

20

156.5

240

320

712

100

IMC-FEC

MAPMT

32

95

SIAElectronics

448

540

SIA 120SIA 120

TASC

TASC-FEC PD

IMC

20

156.5

240

320

712

100

IMC-FEC

MAPMT

32

95

SIAElectronics

448

540

TASC

TASC-FEC PD

IMC

20

156.5

240

320

712

100

IMC-FEC

MAPMT

32

95

IMC-FEC

MAPMT

32

95

SIAElectronics

448

540

HEAD2010 8March 2, 2010

CALET Performance for Electron Observation

SIA

IMC

TASC

Electron 100 GeV

Electron 1 TeV

GeometricalFactor(Blue Mark)

DetectionEfficiency

Energy Resolution

~2%

See Poster for details( Akaike et al.)

HEAD2010 9March 3, 2010

The CALET mission instrument can satisfy the requirements as a standard payload in size, weight, power, telemetry etc. for launching by HTV and observation at JEM/EF.

CALET System Design

＃９Calorimeter

Gamma-ray Burst MonitorStar Tracker

Mission Data Controller

Field of View (45 degrees from the zenith)

JEM/EF & the CALET Port

CALET Payload

Weight : 483.5 kgPower Consumption: 313W

March 3, 2010 HEAD2010 10

CALET

HTV

HTV

ISS

Approach to ISS

Pickup of CALET

H2-B Transfer Vehicle （ HTV)

Launching of H-IIB RocketSeparation from H2-B

Launching Procedure of CALET

CALET

HEAD2010 11March 2, 2010

Electron Observation (5 years) 　

Vela

Expected Anisotropy from Vela SNR

Expected Flux > 1000 827 644

~10% @1TeV

Monogem Cygnus Loop

12

Proton and Nucleus Observation （ 5years)

O

MgNe

FeSi

C

CREAM

2ry/ 1ry ratio ( B/C) Energy dependence of diffusion constant: D ~ Eδ

Observation free from the atmospheric effect up to several TeV/n

Nearby Source Model (Sakar et al.)Leaky Box Model

HEAD2010 13March 3, 2010

Comparison of Detector Performance for Electrons

Detector Energy Range(GeV)

Energy Resolution

e/p Selection Power

Key Instrument(Thickness of CAL)

SΩT（ m ２

srday)PPB-BETS(+BETS)

10 -1000 13% @100 GeV

4000(> 10 GeV)

IMC: (Lead: 9 X0 )

~0.42

ATIC1+2(+ ATIC4)

10 -a few 1000

<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

(20-1000GeV)

Energy dep. GF

Tracker+ACD+ Thin Seg. CAL

(W:1.5X0+CsI:8.6X0)

300@TeV(1 year)

AMS 1-1,000(Due to Magnet)

～ 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: 3 Xo+ PWO : 27

Xo)

220(5 years)

CALET is optimized for the electron observation in the tran-TeV region, and the performance is best also in 10-1000 GeV.

March 3, 2010 HEAD2010 14

A New Technology 　 and Space Experiments after CALETThe Cosmic Ray Electron Synchrotron Telescope (CREST)　　　　　　　　　　　　　　　　　　　　　　　　　　 (ICRC 2009, S.Nutter et al.)CREST payload for Ballooning:40 days at 4 g/cm2 in Antarctica

Challenging New Technology:Synchrotron X rays from electron

Expected electron detection efficiency Very large

acceptance: Vela detection up to 10 TeV (~ a few TeV for HESS ) High Threshold: E> 2 TeV Poor energy

resolution : ~ a factor of two

32x32 BaF2 Crystals(40% coverage)

2.4 m

Ex > 30 keV

TANSUO (J.Chang et al.)

HEPCaT as part of OASIS (J.W. Mitchell et al.)

Hodoscope + BGO Calorimeter

SΩ~0.4 m2 sr

SΩ~2.5 m2 sr

Sampling Silicon-W Calorimeter + Secondary Neutron Detector

HEAD2010 15March 3, 2010

The electron measurement over 1 TeV can bring us very important information of the origin and propagation of cosmic-rays and also of the dark matter ( yet not discussed here). We have successfully been developing the CALET instrument for Japanese Experiment Module (Kibo) – Exposed Facility to extend the electron observation to the tans-TeV region.The CALET has capabilities to observe the electrons up to 10 TeV , gamma-rays in 10GeV- 10TeV , proton and heavy ions in several 10 GeV - 1000 TeV, for investigation of high energy phenomena in the Universe.The CALET mission has been approved by the System Definition Review (SDR) , and will proceed to the Phase B soon for launching in 2013.

Summary and Future Prospect

HEAD2010 16March 3, 2010

International Collaboration Team

Waseda University: 　 S. Torii, K.Kasahara, S.Ozawa, H.Murakami, Y.Akaike, T.Suzuki, R.Nakamura, K.Miyamoto, T.Aiba, M.Nakai, Y.Ueyama, N. Hasebe, J.Kataoka

JAXA/ISAS: M.Takayanagi, H. Tomida, S. Ueno, J. Nishimura, Y. Saito H. Fuke, K.Ebisawa, M.Hareyama

Kanagawa University: T. Tamura, N. Tateyama, K. Hibino, S.Okuno, T.Yuda 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.TakitaYokohama National University: Y.Katayose, M.ShibataHirosaki University: S. Kuramata, M. IchimuraTokyo Technology Inst.: T.Terasawa, Y. TunesadaNational Inst. of Radiological Sciences: Y. Uchihori, H. Kitamura KEK: K.Ioka, N.Kawanaka Kanagawa University of Human Services: Y.Komori Saitama University: K.Mizutani Shinshu University: K.Munekata Nihon University: A.Shiomi 　　　　　　 Ritsumeikan University: M.Mori

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: K. Batkov, M.G.Bagliesi, G.Bigongiari, A.Caldaroe, R.Cesshi, M.Y.Kim, P.Maestro, P.S.Marrocchesi , V.Millucci , R.Zei

University of Florence and INFN: 　 O. Adriani, L. Bonechi,   P. Papini, 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

HEAD2010 17March 2, 2010

CALET

The CALET Mission to Search for Nearby Cosmic-Ray Sources

and for Dark Matter

　　　　　　　　

Shoji Toriie-mail: torii.shoji@waseda.jp

Waseda University 　　　 　　　　　　　　　　　　　

　　　　　　　　　　

CALET

HEAD2010 18March 3, 2010

BACKUP

HEAD2010 19March 2, 2010

Cosmic-ray electrons

Cosmic-rayprotons

Flux of electrons 　 and positrons:

~1 % of protons @10GeV ~0.1 % @ 1000GeV ~0.1 % @ 10 GeV Spectrum of electrons: softer than protons power-law index: e:~-3.0, p:-2.7=> As higher energies, Lower electron flux Lager proton backgrounds

Large amount of exposures with a detector of high proton rejection power (+ charge separation)

Long duration balloon flight in 10~1000 GeV (~10 m2srday) Observation in space for years over 1000 GeV (> 100 m2srday)

Cosmic-ray Energy Spectra

a few electrons/ m2 sr day

a few electrons/ cm2 sr day

Electron and Positron 　Observation

HEAD2010 20March 2, 2010

Astrophysical Source CandidatesSupernova Remnants– Shock Acceleration gives a d/dt E-2exp(-E/Ec) spectrum

injected into the ISM, where Ec ~ 10 TeV.

Pulsar Wind Nebulae (PWNe)– Highly magnetized, fast spinning neutron stars. – Gamma-rays and electron/positron pairs produced along the

magnetic axis– The pairs are accelerated at the PWN termination shock, again

giving a d/dt E-2exp(E/Ec) injection

Microquasars– Relativistic jets sending out beams of mono-energetic electrons

into the ISM

Interactions of CR nuclei with interstellar gas– producing +/- or K+/- +/- e+/-

HEAD2010 21March 2, 2010

New Calculation for SNR Origin 　 S.Profumo 　 arXiv:0812.4457v2 28 Apr. 2009

Electron + Positron

Positron Ratio

Source Candidates

HEAD2010 22March 2, 2010

CALorimetric Electron Telescope

Dark Matter

Japanese Experiment Module (Kibo)

International Space Station

Cosmic Ray Sources

SNRγ

γ

PairAnnihilation

Pulsar AGN

γ eP χ χ

e+

e-

CALET

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

CALET

HEAD2010 23March 2, 2010

Launch of the H-IIB Launch Vehicle Test Flight Launched on Sep.11, 2009 at Yoshinobu Launch Complex at

the Tanegashima Space Center in Japan Docked successfully to ISS on Sep. 18, 2009.

c JAXA

HEAD2010 24March 2, 2010

MAXISMILES SEDA

Payloads on Japanese Experiment Module (Kibo) /Exposure Facility at Present

c JAXA

HEAD2010 25March 2, 2010

MAXISMILES

SEDA-AP

衛星間通信システム

実験ポート

HREP

MCE

CALET

Future Plan of JEM/EF (~2013)

HEAD2010 26March 2, 2010

Electron Observation (5 years) – Astrophysical Model- 　

KK DM(Δt=0) vs SNR type (Δt=105 year)

----- KK DM SNR Type

SNR Type vs Pulsar (Δt=3×105 year)

----- Pulsar Type SNR Type

CALET Observation CALET Observatuib

age=5.6x105

yr,Ee=1.7x1050

erg,spectral index=1.7

Source

200spindown0 /1

)( t

ELtQ tot

000

4ln exp4ln )(tEtQ tot

00

SNR Type （ exp(-t) ）　　　　　　 Pulsar Type （ｔ -2)

HEAD2010 27March 2, 2010

Dark Matter Search Efficiency

Expected electron + positron excess by KK dark matter (Mass 620 GeV) by the CALET observation

2 　 years （ BF=40) or 5 years （ BF=16)

2 years （ BF=5) or 5 years （ BF=2)

Expected gamma-ray excess by SUSY DM( Mass = 820GeV) by the CALET observation

28March 2, 2010 HEAD2010

AMS (stars) HEAT (triangles)BETS (circles) PPB-BETS (crosses)Emulsions (diamonds) ATIC (red circles)

Observed (e++e-)Spectra (as of 2008) & e+/(e++e-) Ratio

• If we assume the power law spectrum ( with γ=-3.3) calculated by GALPROP, an excess of (e++e-) is seen in 300-800 GeV.• The excess might be contributed from

exotic sources: Nearby Pulsars or WIMPs.

J. Chang et al. Nature (2008)

Nature

MLP+BDTD(+data, no pre-sampler,improved knowledge of detectors)

GALPROP

PAMELA e+/(e++e-) Ratio (RICAP, 2009)statistics improved by ~2.5 ÷ 3

• The positron ratio observed by PAMELA presents unexpected increase over 10 GeV.• This increase can be understood if the positrons are created by Nearby Pulsars or WIMPs in addition to secondary process.

Both anomalies from same reason ?To identify the reason, Anisotropy in (e++e-) and e+/(e++e-) over 100 GeV are indispensable.

HEAD2010 29March 2, 2010

Then, excellent observations of (e++e-) in statistics are carried out by FERMI-LAT and HESS, and a new era of electron observation is opened probably by indicating a flattening of energy spectrum and a sharp cut-off over 1 TeV, respectively.

I really appreciate their efforts to derive the electron spectrum in unexploded region.

F.Aharanian et al. arXiv:0905:0105

HEAD2010 30March 2, 2010

Gamma-ray

CALET Performance for Electron Observation (2) Angular Resolution

ElectronSΩ ( for electrons) 　 vs Incident Angle

Integral

Differential See Blue Marks

HEAD2010 31March 2, 2010

Why we need CALET ?

Geometric Factor

Residual hadron contamination

FERMI Electron AnalysisGeometric Factor depends strongly on energy

Proton rejection power depends fully on simulation by using different parameters

Energy resolution becomes worse at high energies (~30 %@ 1 TeV)

Expected CALET PerformanceGeometric Factor is constant up to 10 TeV

Energy resolution is nearly 2 %, and constant over 100 GeV

104

1.6 M protons

Proton rejection power at 4 TeV is better than 105

with 95 % electron retainedBlue Mark

CALET is a dedicated detector for electrons and has a superior performance in the trans-TeV region as well as at the lower energies

HEAD2010 32March 2, 2010

Validation of the flight data

Task: compare the efficiency of all “cuts” for flight data and MC eventsApproach: - Plot from the flight data the histogram of each variable involved in the electron selections, one at a time, after applying all other cuts - check if the flight histograms match the simulated ones, and account for the differences in systematic errors for the reconstructed spectrum

Example for the variable (shower transverse size)

Analysis variables demonstrate good agreement between the flight data and MC

HEAD2010 33March 2, 2010

F.Aharanian et al. arXiv:0905:0105 PRL ,201, 261104 (2008)

The H.E.S.S. analysis depends on simulation, and the residual protons are as dominant as similar with an amount of the electrons, or more at lower energies.

HEAD2010 34March 2, 2010

Calorimeter Thickness: 17 X0

=> Energy Leakage over 50 GeV

NIM 490 (2002) 132