Präzisionsmessungen zur kosmischen Höhenstrahlung im Weltraum Das AMS Experiment auf der ISS Prof. Dr. Stefan Schael RWTH Aachen

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1 Präzisionsmessungen zur kosmischen Höhenstrahlung im Weltraum Das AMS Experiment auf der ISS Prof. Dr. Stefan Schael RWTH Aachen 1

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3 Cosmic Particle Spectrum 3

Suche nach Anti-Materie 10-10 10-9 Gauss 1.

kennen. 2. Es gibt Bereiche im Universum die aus Anti-Materie bestehen.

4 Suche nach Anti-Materie Gauss 1. Es gib eine Asymmetrie zwischen Materie und Anti-Materie die wir noch nicht kennen. 2. Es gibt Bereiche im Universum die aus Anti-Materie bestehen. => AMS Experiment 5µG l=8mly t=4 My He : Kosmische Antimaterie!" $ # p / p < 30% at 1 TeV C : Anti-Sterne "% 4

5 Dark Matter log d Dark Energy v = H! d redshift z = (! "! ) /! 0 CMBR: Boomerang m ΔT(α,δ) = Σ l,m a l,m Y l (α,δ) : anisotropies - expansion in multipoles c l = < a 2 l,m > : power spectrum of anisotropies 5

baryons + cold dark matter + dark energy the critical density for a flat universe: 2 3H0

6 Dark Matter & Dark Energy From Cosmic Background Radiation, Supernova 1a and Big bang nucleosynthesis Ω total = Ω b + Ω CDM + Ω Λ = (5±1)% + (31±7)% + (65±5)% = (99±3)% baryons + cold dark matter + dark energy the critical density for a flat universe: 2 3H0 3! c = $ 3 H-atoms / m 8" G! H % = h =! 100kms Mpc c # 1 # 1 h = 0.65 ± 0.08 t = 13 ± 2Gyr 6

7 Search for Dark Matter From various observations we now that 90% of the matter of the universe in non luminous. DarkSusy The preferred candidate for dark matter is today the neutralino χ. m(χ) = 116 GeV tanβ = 5 Ω M = 0.28 Requires Proton/Positron separation on the 10-6 level 7

Maximale Ausgasrate auf der ISS: < 1 10-14 g/s/cm 2 Maximales Gewicht 14900 lbs Kosten: 10000 $/lbs

8 Technische Anforderungen an das AMS Experiment Bei Start/Landung treten Beschleunigungen bis zu 9g auf Das Experiment wird im Vakuum betrieben Temperaturschwankungen von Grad Celsius Maximale Ausgasrate auf der ISS: < g/s/cm 2 Maximales Gewicht lbs Kosten: $/lbs Maximaler Stromverbrauch: 2kW, 1 Stromkabel mit 120 V Maximale Datenrate: 1Mbyte/s 1 optischer Link zur ISS 8

9 AMS-01 Configuration on STS-91 Flight STS-91 Flight, June 2-12 th, years from proposal to launch Magnet: Nd 2 Fe 14 B, BL 2 = 0.15 TM 2 T.o.F: Four planes of scintillators; β and Z measurements, up/down separation Tracker: Six planes of ds silicon detectors; Charge sign, de/dx up to Z=8, Rigidity (p/z) Anticounters: Veto stray trajectories and background particles from magnet walls Aerogel Threshold Čerenkov: β measurements (1 3 GeV/c) for better e/p separation Low Energy Particle Shielding (LEPS): Carbon fibre, shield from low energy (<5MeV) particles 9

AMS-01: STS-91 Flight Results Data taking 135 hours Shuttle altitude 370 km Trigger rate 100 700 Hz 100

10 AMS-01: STS-91 Flight Results Data taking 135 hours Shuttle altitude 370 km Trigger rate Hz 100 million events recorded Energy Range: 100 MeV/n<E k < 300 GeV/n Electronics channels: Power: 1 kw Weight: 3 t 10

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12 Stability of the Si-tracker 12

13 Search for anti-matter with AMS-01 N N He He < "! (@ 95% CL) >50 contributions related to AMS-01 at ICRC 2001 in Hamburg 13

14 Search for Anti-Matter with AMS-02 Time on ISS: 3 years AMS02 statistics 10 3 AMS01 superconductivity magnet B-field: 0.15 T 0.9 T momentum reach x 6 exclude a sphere of 1000 Mpc 14

15 Full GEANT simulation of the earth leads to a detailed understanding of the measured spectra. 15

Expected data for AMS02: 1. 1 10 9 He 1-1400 GV 2.

16 Expected data for AMS02: He GV e GeV p GeV p + > 1 TeV e - > 10 GeV 16

17 AMS-02 17

18 , Karlsruhe 18

TRD: Particle ID & 3D tracking 20 layers fleece + Xe/CO2 gas 5248 channels, 6mm straw tubes p + /e + < 10-2 from 10 300 GeV Upper TOF, 2 layers, Trigger, s t @ 125 ps Anticoincidence (VETO) counter

19 TRD: Particle ID & 3D tracking 20 layers fleece + Xe/CO2 gas 5248 channels, 6mm straw tubes p + /e + < 10-2 from GeV Upper TOF, 2 layers, Trigger, s 125 ps Anticoincidence (VETO) counter Double sided Si-strip tracker with internal laser alignment system, CFC support structure 6 m 2 in 3 double and 2 single layers 1s charge separation up to 1 TeV Super conducting magnet (ETH Zürich) B=0.9T, V=0.6m 3, 2600 l He Lower TOF, 2 layers, 1.3 m distance p + /e + > 3 s below 2 GeV RICH AGL+NaF Radiator for A<28 and Z<29 separation > 3 s from 1-12 GeV ECAL 3D sampling lead/scint.-fibre p + /e + < 10-4 from GeV 19

20 AMS02 Transition Radiation Detector 20

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23 TRD Support Structure 23

24 Required mechanical accuracy < 0.1 mm 24

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27 Gas Gain Measurements 27

28 Total loss by diffusion: mbar/s at 1 bar Quality control during production: mbar/s at 1 bar 1760 l Xe and 440 l CO2 in 1000 days 28

29 TRD Gas System: MIT Storage: 44.3 kg Xe 3.7 kg 50 bar 8100 l Xe 2000 l CO2 Extra safety factor of 5!!! 29

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31 Vibration test up to 6.8 g (90 s) 31

32 FE-model measured after vibration test 1 after thermo vacuum test after vibration test 2 1. eigenfrequency [Hz] x y z

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Leak Rates Diffusion limit: 1.2 10-5 mbar/s Xe/CO 2 1.

34 Leak Rates Diffusion limit: mbar/s Xe/CO mbar/s He TRD design: total gas volume 5 x leak rate mbar/s Xe/CO 2 Consequences: 1. we can not use EPO-TEK 353 ND glue 2. new design for gas connection use stainless steel tubes instead of peak 34

Cleaning (CH 2 Cl 2 ) of the radiator has been done at the Institute for Organic Chemistry of

35 TRD radiator The fleece material (Polypropylene, LRP 375 BK) has been produced and cut to the required width. We have cut the radiator (4000 pieces) to the appropriated length. Cleaning (CH 2 Cl 2 ) of the radiator has been done at the Institute for Organic Chemistry of the RWTH Aachen. after cleaning the material fullfills the NASA outgasing limit of: < g/s/cm 2 35

36 TRD Upper TOF Combined Thermal Control TOF TRD 20 Watt TOF & TRD connected to the same M-Structure Contract has been placed with OHB & CGS 36

37 Radiative link between the PCB s (UFE boards) and the radiator: 37

38 First results from the TRD thermal model: 38

39 TRD FE-electronics: 20 Watt for 5248 channels => multiplexed pulsheight only V 39

40 FE-electronic: Space Qualification Vibration test up to 6.8 g (90 s), thermo vaccum test (-30 C, +60 C) 40

41 IEKP Karlsruhe, Prof. Dr. W. de Boer DAQ with 2x/3x redundancy UDR for data reduction (1Mbyte/s limit) R&D: Karlsruhe, RWTH, MIT, Geneva, C.A.E.N. Production: CSIST (Taiwan) 41

42 TRD Test Beam Results I 20 layer TRD detector in the test beam at CERN in 2000 we have recorded 3 million events providing signals for protons, electrons, muons and pions at energies from GeV Muon events have been used for an intercalibration of the individual straws to a relative accuracy of 2%. 42

43 TRD Testbeam Results Proton Contamination The TRD fulfills the specification of: proton contamination < 1% at an electron efficiency of 90% up to 260 GeV 43

44 Summary AMS offers a world wide unique discovery potential for new physics to build a modern particle physics detector which can be operated in space for 3 years is a technical challenge we are looking forward to the liftoff in Summer

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