Relative abundance of elements at Earth

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3 Relative abundance of elements at Earth cosmic rays - solar system ~ 1 GeV/n Si = 100 JRH, Adv. Space Res. 41 (2008) 442

4 TRACER Energy Spectra for individual elements D. Müller et al., ICRC 2007

5 Energy spectra of main elements in cosmic rays

6 SNR acceleration: Sveshnikova Diffusion: Kalmykov+JRH 2007 poly gonato ~Z JRH, Adv. Space Res. 41 (2008) 442

7 SNR acceleration: Sveshnikova Diffusion: Kalmykov+JRH 2007 poly gonato ~Z JRH, Adv. Space Res. 41 (2008) 442

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10 Transport equation for cosmic rays in the diffusion Galaxy energy loss (Bethe Bloch) loss through interactions! with ISM (spallation) loss through radioactive decay N i t = (D i N i ) E (b in i ) nνσ i N i N i γτ i + Q i + j>i nνσ ij N j + j>i N j γ j τ ij source term production through spallation! of heavy neulcei production through decay! of heavy nuclei

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12 Age of galactic cosmic rays Residence time in Galaxy 10Be 10B + e- (τ= a) 10Be 10B e- τ = 17*106 a

13 Relative abundan Pathlength of cosmic rays Nuclear charge num Fig. 3. Abundance of elements in cosmic rays as function of their nuclear charge num Abundance for nuclei with Z 6 28 according to Simpson (1983). Heavy nuclei as measured 3 (Binns et al., 1989), SKYLAB (Shirk and Price, 1978), TIGER (Lawrence et al., 1999), T g/cm2of elements in the as well as UHCRE (Donelly et al., 1999). In addition, the abundance C B+n+p λ(e) E experime 0.15 g/cm =10 g/cm The sp B/C 0.3 tion influ assumed 0.25 same slo 0.2 ing the e and the =5 g/cmaccount, 0.1 nuclei sh (Ho rand (Sc+V)/Fe 0.05 for iron n 0 sponding indicate Energy [MeV/n] compare N. Yanasak, ApJ 563 (2001) 768 ues for Fig. 4. Abundance ratio of boron to carbon and scandium + vanadium to Relative abundance spallation primary/secondary-ratio HEAO-3 ACE/CRIS

14 TRACER - Mc Murdo, Antarctica, 2003

15 charge Transition Radiation Array for Cosmic Energetic Rays de/dx trajectory energy TR trajectory energy suppress low energy particles Geometric factor: 5 m 2 sr 1600 proportional tubes total

16 Transition Radiation Array for Cosmic Energetic Radiation Ft. Sumner, New Mexico 1 day 1999 McMurdo, Antarctica 10 days Z 26 Kiruna, Sweden 4 ½ days Z 26 Responses in arb.units Direct measurement of the composition of cosmic rays from 0.5 to 10,000 GeV/amu with single elemental resolution Combined responses for energy measurements over 4 decades: Cherenkov: GeV/amu (n=1.49) Specific Ionization in gas: GeV/amu TRD: 400 several 10,000 GeV/ amu Lorentz factor γ L ~ (1 1/n 2 β 2 ) de/dx ~ 1/β 2 ln (E) TR = de/dx + x-rays all signals scale with Z 2 5m 2 sr - currently the largest cosmic-ray detector on balloons

17 TRACER - Mc Murdo, Antarctica, 2003 A. Romeo J.R. Hörandel P. Boyle G. Kelderhouse D. Müller D. Pernik M. Ave-Pernas

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20 Cosmic-ray propagation B/C ratio 7.2. Discussion of the Result 77 path length B/C ratio TRACER HEAO CRN ATIC CREAM AMS-01 ] 2 escape pathlength! esc [g/cm 10 1 Leaky-Box Fit GALPROP -0.6 "! E kinetic Energy [GeV/amu] Figure 3: The boron-to-carbon abundance ratio as a function of kinetic energy per nucleon. Error bars are statistical (thin) and systematic (thick). Previous measurements are shown from HEAO [6], CRN [11], ATIC [9], CREAM [2] A. Obermeier et al., ICRC (2011) kinetic energy [GeV/amu] Figure 7.4: The escape pathlength Λ esc as derived from the TRACER measurement with δ =0.53 ± 0.06 and Λ 0 =0.31± g/cm2. The escape pathlength is defined in Eq The dashed lines illustrate the 1σ uncertainty range for the escape pathlength. A. Obermeier, PhD thesis, RU Nijmegen (2011) Using the same power-law index that fits the low-energy data, δ =0.6, avalueforthe 3 4

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