340 likes | 467 Views
The Future Prospects for Electron Measurements, the Frontier above 1 TeV. Shoji Torii Waseda University. d N /dE E -2 exp(-E/E c ). Log(dN/dE). ⇒. ↑. E c. Log(E). Annihilation of Dark Matter ( WIMP). χχ→e + ,e -. Constitutes of the Universe. Heavy Element. 重元素. 宇宙の質量構成比.
E N D
The Future Prospects for Electron Measurements, the Frontier above 1 TeV Shoji Torii Waseda University HEAD2010
dN/dE E-2exp(-E/Ec) Log(dN/dE) ⇒ ↑ Ec Log(E) Annihilation of Dark Matter(WIMP) χχ→e+,e- Constitutes of the Universe Heavy Element 重元素 宇宙の質量構成比 宇宙の質量構成比 重元素 重元素 0.03% 0.03% 0.03% 0.03% Neutrino ニュートリノ 0.3% 0.3% ニュートリノ ニュートリノ 0.3% 0.3% 星 Star 0. 0.5 % % 5 星 星 0. 0. % % 5 5 暗黒エネルギー 暗黒エネルギー 暗黒エネルギー 暗黒エネルギー Hydrogen、 水素、 暗黒エネルギー 暗黒エネルギー 暗黒エネルギー 暗黒エネルギー 暗黒物質 暗黒物質 暗黒物質 暗黒物質 Helium ヘリウム 水素、 水素、 暗黒物質 暗黒物質 暗黒物質 暗黒物質 % % 4 4 ヘリウム ヘリウム % % 4 4 暗黒物質 Dark Matter 暗黒物質 暗黒物質 23% 25% 25% 25% Dark Energy 暗黒エネルギー 70% 73% Electron & Positron Observation Astrophysical Origin Production Spectrum (Power Law Distribution +Cutoff) • Propagation in the Galaxy • Diffusion Process • Energy Loss • dE/dt =-bE2 • (Syncrotron+Inverse Compton) Shock Wave Acceleration in SNR Acceleration in PWN • +/- or K+/- +/- e+/- ⇒ e++e- ⇒ Evolution of the Universe Dark Matter Origin ⇒ Mχ Production Spectrum (ⅰ) Monoenergetic: Direct Production of e+e- pair (ⅱ) Uniform:Production via Intermediate Particles (ⅲ) Double Peak: Production by Dipole Distribution via Intermediate Particles HEAD2010
e± Propagation Diffusion Injection Energy loss by IC & synchro. ← B/C ratio For a single burst with Power law spectrum Atoyan 95, Shen 70 Kobayashi 03 HEAD2010
A Naïve Result from Propagation 1 GeV Electrons 100 TeV Electrons T (age) = 2.5 X 105 X (1 TeV/E) yr R (distance) = 600 X (1 TeV/E)1/2 pc GALPROP/Credit S.Swordy • 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? (F0: E3 x Flux at 3TeV) HEAD2010
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
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. • We are waiting for much more study by ATIC, PAMELA, Fermi-LAT, HESS • and 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. HEAD2010
CALET Overview • 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) • PWO20mmx20mmx320mm • 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 • 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) HEAD2010
CALET Performance for Electron Observation Electron 100 GeV Geometrical Factor (Blue Mark) SIA IMC Detection Efficiency TASC Electron 1 TeV Energy Resolution ~2% See Poster for details ( Akaike et al.) HEAD2010
CALET System Design JEM/EF & the CALET Port 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 Payload Star Tracker Gamma-ray Burst Monitor Calorimeter #9 Field of View (45 degrees from the zenith) Mission Data Controller Weight : 483.5 kg Power Consumption: 313W HEAD2010
CALET CALET ISS HTV HTV Launching Procedure of CALET H2-B Transfer Vehicle(HTV) Pickup of CALET Approach to ISS Separation from H2-B Launching of H-IIB Rocket HEAD2010
Electron Observation (5 years) Expected Anisotropy from Vela SNR ~10% @1TeV Expected Flux > 1000 827 644 Cygnus Loop Vela Monogem HEAD2010
Proton and Nucleus Observation (5years) 2ry/ 1ry ratio ( B/C) • Energy dependence of diffusion constant: D ~ Eδ • Observation free from the atmospheric effect up • to several TeV/n C O CREAM Mg Ne Leaky Box Model Si Fe Nearby Source Model (Sakar et al.)
Comparison of Detector Performance for Electrons CALET is optimized for the electron observation in the tran-TeV region, and the performance is best also in 10-1000 GeV. HEAD2010
A New Technologyand Space Experiments after CALET The Cosmic Ray Electron Synchrotron Telescope (CREST) (ICRC 2009, S.Nutter et al.) TANSUO (J.Chang et al.) Hodoscope + BGO Calorimeter CREST payload for Ballooning: 40 days at 4 g/cm2 in Antarctica Challenging New Technology: Synchrotron X rays from electron SΩ~0.4 m2sr 2.4 m 32x32 BaF2 Crystals (40% coverage) Ex > 30 keV HEPCaT as part of OASIS (J.W. Mitchell et al.) • 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 Expected electron detection efficiency Sampling Silicon-W Calorimeter + Secondary Neutron Detector SΩ~2.5 m2sr HEAD2010
Summary and Future Prospect • 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. HEAD2010
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.Kamioka ICRR, University of Tokyo: Y.Shimizu, M.Takita Yokohama National University: Y.Katayose, M.Shibata Hirosaki University: S. Kuramata, M. Ichimura Tokyo Technology Inst.: T.Terasawa, Y. Tunesada National 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.ShiomiRitsumeikan University: M.Mori NASA/GSFC: J.W.Mitchell, A.J.Ericson, T.Hams, A. A.Moissev, J.F.Krizmanic, M.Sasaki Louisiana State University: M. L. Cherry, T. G. Guzik, J. P. Wefel Washington University in St Louis: W. R. Binns, M. H. Israel, H. S. Krawzczynski University 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.Vannuccini University of Pisa and INFN:C.Avanzini, T.Lotadze, A.Messineo, F.Morsani Purple Mountain Observatory: J. Chang, W. Gan, J. Yang Institute of High Energy Physics:Y.Ma, H.Wang,G.Chen HEAD2010
CALET The CALET Mission to Search for Nearby Cosmic-Ray Sources and for Dark Matter CALET Shoji Torii e-mail: torii.shoji@waseda.jp Waseda University HEAD2010
BACKUP HEAD2010
Electron and PositronObservation Cosmic-ray Energy Spectra • Flux of electronsand 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 Cosmic-ray protons Cosmic-ray electrons a few electrons / cm2 sr day a few electrons / m2 sr day => 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) HEAD2010
Astrophysical Source Candidates • Supernova 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
New Calculation for SNR Origin S.ProfumoarXiv:0812.4457v2 28 Apr. 2009 Source Candidates Positron Ratio Electron + Positron HEAD2010
γ AGN e+ Pulsar SNR P χ χ e γ Pair Annihilation e- γ CALET Cosmic Ray Sources Dark Matter International Space Station Japanese Experiment Module (Kibo) CALorimetric Electron Telescope CALET A Dedicated Detector for Electron Observation in 1GeV – 10,000 GeV HEAD2010
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
Payloads on Japanese Experiment Module (Kibo) /Exposure Facility at Present MAXI c JAXA SMILES SEDA HEAD2010
SEDA-AP HREP MCE 実験ポート CALET MAXI SMILES 衛星間通信システム Future Plan of JEM/EF (~2013) HEAD2010
CALET Observation CALET Observatuib ----- KK DM SNR Type Electron Observation (5 years) – Astrophysical Model- KK DM(Δt=0) vs SNR type (Δt=105 year) SNR Type vs Pulsar (Δt=3×105 year) ----- Pulsar Type SNR Type SNR Type(exp(-t)) Pulsar Type(t-2) Source age=5.6x105 yr, Ee=1.7x1050 erg, spectral index=1.7 HEAD2010
Dark Matter Search Efficiency Expected electron + positron excess by KK dark matter (Mass 620 GeV) by the CALET observation Expected gamma-ray excess by SUSY DM ( Mass = 820GeV) by the CALET observation 2 years(BF=5) or 5 years(BF=2) 2years (BF=40) or 5 years(BF=16) HEAD2010
Observed (e++e-)Spectra (as of 2008) & e+/(e++e-) Ratio J. Chang et al. Nature (2008) PAMELA e+/(e++e-) Ratio (RICAP, 2009) statistics improved by ~2.5 ÷ 3 Nature AMS (stars) HEAT (triangles) BETS (circles) PPB-BETS (crosses) Emulsions (diamonds) ATIC (red circles) MLP+BDTD (+data, no pre-sampler, improved knowledge of detectors) GALPROP • 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. • 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. Both anomalies from same reason ? To identify the reason, Anisotropy in (e++e-) and e+/(e++e-) over 100 GeV are indispensable. HEAD2010
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. F.Aharanian et al. arXiv:0905:0105 I really appreciate their efforts to derive the electron spectrum in unexploded region. HEAD2010
CALET Performance for Electron Observation (2) Angular Resolution SΩ ( for electrons)vs Incident Angle Electron Differential See Blue Marks Integral Gamma-ray HEAD2010
Residual hadron contamination Why we need CALET ? Proton rejection power depends fully on simulation by using different parameters CALET is a dedicated detector for electrons and has a superior performance in the trans-TeV region as well as at the lower energies 104 FERMI Electron Analysis Energy resolution becomes worse at high energies (~30 %@ 1 TeV) Geometric Factor depends strongly on energy Expected CALET Performance Energy resolution is nearly 2 %, and constant over 100 GeV Proton rejection power at 4 TeV is better than 105 with 95 % electron retained Geometric Factor is constant up to 10 TeV Blue Mark 1.6 M protons HEAD2010
Validation of the flight data Example for the variable (shower transverse size) Task:compare the efficiency of all “cuts” for flight data and MC events Approach: - 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 theflight histogramsmatch the simulated ones, and account for the differences insystematic errors for the reconstructed spectrum Analysis variables demonstrate good agreement between the flight data and MC HEAD2010
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. F.Aharanian et al. arXiv:0905:0105 PRL ,201, 261104 (2008) HEAD2010
CalorimeterThickness: 17 X0 => Energy Leakage over 50 GeV NIM 490 (2002) 132 HEAD2010