Cosmic Ray Isotopes measured by AMS F. Giovacchini - CIEMAT on - PowerPoint PPT Presentation

Cosmic Ray Isotopes measured by AMS F. Giovacchini - CIEMAT on behalf of the AMS-02 collaboration

Light Isotopes on Cosmic Rays Precise measurements of chemical composition of CRs with AMS (See M.P and V.F) provide important information for understanding the origin and propagation of CRs in the galaxy; More detailed description from Isotopic composition: Isotopes in light cosmic rays D/p : secondary/primary with D mainly from 4 He • 3 He/ 4 He : • 4 He mainly produced and accelerated in sources (prim.); 3 He mainly produced by collision of 4 He with the ISM (sec.). à Unique probe for propagation 6 Li/ 7 Li : both mainly determined by the secondary • production cross sections from C, N, O fragmentation. Light secondary like D, 3 He and Li probe the properties of diffusion at larger distance than heavier secondary like B. 10 Be : complementary tool relevant to estimate the • residence time of CRs in the galaxy: 10 Be: t 1/2 = 1.4 My, comparable to the average CRs lifetime F.Giovacchini TAUP2019, Toyama 2

Isotopic composition with AMS m = ZR / βγ βγ L1 σ (m)/m = σ (R)/R ⊕ γ 2 σ ( β )/ β TRD Z measurement: TOF Upper UTOF L1 - UTOF - Inner Tracker - LTOF L2 L2-L8: à Negligible misidentification L3,L4 Inner MAGNET L5,L6 R measurement: Tracker Tracker (Inner), R=p/Z L7,L8 Δ R/R(R<20 GV)~10% TOF Lower LTOF β Measurement: RICH TOF L9 ECAL RICH F.Giovacchini TAUP2019, Toyama 3

Isotopic composition with AMS Velocity from TOF: TOF UPPER TOF Δβ / β 2 ≈ 4% for Z=1, 2% for Z=2 and 1%-2% for Z>2 PLANE 1 Velocity from RICH (2 radiators): PLANE 2 RICH-NaF ( β >0.75): Δβ ≈0.35% (Z=1) and Δβ <0.25% @ β ~1 (Z>1) LOWER TOF RICH-Agl ( β >0.96): Δβ ≈0.12% (Z=1) and Δβ <0.07% @ β ~1 (Z>1) PLANE 3 PLANE 4 − 3 × 10 4.5 D,p 4 3.5 RICH He 3 NaF Aerogel Δβ 2.5 β Li σ 2 Mirror Be PMT 1.5 matrix 1 0.5 0 0 2 4 6 8 10 F.Giovacchini TAUP2019, Toyama 4 Z

Deuteron identification with AMS à Analysis in 3 different energy ranges TOF β range, Ekin: 0.45 GeV/n To identify the isotopes: Mass • templates are obtained from MC simulation of D and p Contamination from interaction • inside the detector accounted from MC, validated with direct measurement in AMS from MC simulation F.Giovacchini TAUP2019, Toyama 5

Deuteron Flux and D/p 0.12 BESS00(2000/08) 0.1 CAPRICE94(1994/08) • D/p ratio vs Ekin per nucleon IMAX92(1992/07) PAMELA-CALO(2006/07-2007/12) à Extends the measurement up to 10 GeV/n D/p ratio 0.08 PAMELA-TOF(2006/07-2007/12) AMS (2011-2016) D/p 0.06 0.04 0.02 Flux [(m 2 sec sr GV -1 ) -1 ] Preliminary data, refer to Preliminary data, refer to upcoming AMS PRL publication upcoming AMS PRL publication D 0.2 0.3 0.4 0.5 0.60.70.8 0.91 2 3 4 5 6 7 8 9 E kin [GeV/n] Ekin [GeV/n] • First precision measurement of D above 1 GeV/n Preliminary data, refer to Preliminary data, refer to upcoming AMS PRL publication upcoming AMS PRL publication E kin [GeV/n] F.Giovacchini TAUP2019, Toyama 6

Helium Isotopes identification with AMS02 5 5 10 10 TOF a) 0.8149 < β < 0.8160 4 3 He 4 10 10 Data 4 He Fit 3 3 Events 10 10 Helium is the second most abundant specie in CRs 2 2 10 10 10 10 1 1 1 2 3 4 5 1 2 3 4 5 R [GV] R [GV] To identify the isotopes: RICH,NaF 4 4 0.9532 < β < 0.9537 10 b) 10 - Unfold the momentum distribution, within the beta 3 He Data 4 He 3 3 10 10 bin, using the tracker resolution function to get 3 He Fit Events 2 2 10 10 and 4 He peaks and count events on TOP of AMS. 10 10 - Fold back the results and Fit to the data. 1 1 4 6 8 10 4 6 8 10 R [GV] R [GV] RICH, Agl c) 0.9863 < β < 0.9864 4 3 He 4 10 10 Data 4 He 3 3 10 10 Events Fit 2 2 10 10 10 10 1 1 5 10 15 20 25 5 10 15 20 25 F.Giovacchini TAUP2019, Toyama 7 R [GV] R [GV]

3 He/ 4 He vs Ekin Data: 6.5 y (05/2011 to 11/2017) Submitted to PRL AMS-02 4 He: 100 million refer to upcoming AMS publication 0.3 PAMELA-CALO 3 He: 18 million PAMELA-TOF IMAX-92 0.25 He BESS-98 4 Φ BESS-93 / He 0.2 GALPROP 3 Φ 0.15 0.1 E [GeV/n] K 2 4 6 8 10 F.Giovacchini TAUP2019, Toyama 8

3 He and 4 He and ratio time variation Above 4GV the ratio vs R is time independent 20 Data: 6.5 y a) 2.15 < R < 2.40 GV a) 2.15 < R < 2.40 GV 100 t i = February 28±42, 2015 0.18 15 (05/2011 to 11/2017) 10 50 0.16 5 0.14 0 0 4 He and 3 He 0.18 b) 2.97 < R < 3.29 GV b) 2.97 < R < 3.29 GV 10 60 Fluxes and ratio 0.16 40 5 ] ] -1 -1 20 0.14 vs time in 21 sr s GV) sr s GV) 0.18 2010 2012 2012 2013 2014 2016 2016 2017 2010 2012 2012 2013 2014 2016 2016 2017 periods of 4 c) 3.64 < R < 4.02 GV c) 3.64 < R < 4.02 GV He 6 40 4 0.16 Φ Bartels rotations 30 4 / He 0.14 2 2 20 [(m [(m each (108 days) 3 Φ 2 10 0.12 2010 2012 2012 2013 2014 2016 2016 2017 2010 2012 2012 2013 2014 2016 2016 2017 d) 4.02 < R < 4.43 GV He d) 4.02 < R < 4.43 GV He 5 0.16 30 4 3 Φ Φ 4 0.15 3 20 0.14 0.13 2 10 0.105 2010 2012 2012 2013 2014 2016 2016 2017 2010 2012 2012 2013 2014 2016 2016 2017 e) 14.10 < R < 15.30 GV e) 14.10 < R < 15.30 GV 0.17 1.7 0.16 1.6 0.1 0.15 Submitted to PRL 1.5 Submitted to PRL 0.095 refer to upcoming AMS publication refer to upcoming AMS publication 0.14 1.4 201 1 2012 20 13 201 4 201 5 2016 201 7 201 8 F.Giovacchini 201 1 2012 201 3 201 4 201 5 2016 201 7 201 8 9

Helium Isotopes Flux vs R AMS time-averaged 3 He and 4 He Fluxes as function of rigidity with total error Data: 6.5 years (May 2011 to Nov 2017) ] -1 ) 100 million 4 He : 2.1-21 GV -1.7 3 10 sr s GV 4 18 million 3 He : 1.9-15 GV He 3 He 2 [(m 2.7 R 2 10 The shaded regions show × Submitted to PRL Φ refer to upcoming AMS publication the range of time variation R [GV] 2 3 4 5 6 7 8 9 10 20 F.Giovacchini TAUP2019, Toyama 10

Helium Isotopes ratio vs R AMS time-everaged 3 He/ 4 He as function of rigidity with total error No previous measurement of the 3 He/ 4 He ratio vs R. Δ =-0.294 ± 0.004 Above 4GV the ratio has a rigidity dependence well described by a single power law Submitted to PRL refer to upcoming AMS publication F.Giovacchini TAUP2019, Toyama 11

Lithium Isotopes identification with AMS02 Mass templates reconstructed from the β resolution and • R resolution models obtained from MC simulation. TOF NaF AGL F.Giovacchini TAUP2019, Toyama 12

Lithium Isotopes Fluxes vs Ekin Preliminary data, refer to • First measurement of 6 Li and 7 Li upcoming AMS PRL publication fluxes above 0.3 GeV/n. Data Set: 6.5 years (May 2011 to Nov 2017) Preliminary data, refer to Preliminary data, refer to upcoming AMS PRL publication upcoming AMS PRL publication F.Giovacchini 13 TAUP2019, Toyama

Lithium Isotopes ratio vs Ekin • First measurement of 6 Li / 7 Li flux ratio above 1 GeV/n. Preliminary data, refer to upcoming AMS PRL publication F.Giovacchini 14 TAUP2019, Toyama

Prospect: Beryllium Isotopes Being Beryllium isotopes pure secondary CRs, the ratio 10 Be/ 9 Be (where 10 Be unstable) can be • used to estimate the CRs lifetime Experimentally challenging, lack of measurements • AMS collected over 1 million Beryllium events • At the limit of the resolution but promising • AGL, Ekin [4.44,4.91] GeV/n CRDB (http://lpsc.in2p3.fr/crdb) 0.2 Balloon(1973/08) Balloon(1977/05) 0.15 Balloon(1977/09) Be ISEE3-HKH(1978/08-1979/08) 0.1 Be/ 10 0.05 0 − 1 10 1 10 Ekn [GeV/n] F.Giovacchini 15 TAUP2019, Toyama

Conclusions Ø Isotopic composition of light nuclei in cosmic rays is a key measurement to understand cosmic rays origin and propagation. Ø AMS is publishing a precision measurement of the CRs 3 He and 4 He isotopes fluxes and their ratio with rigidity from 1.9 GV to 15 GV for 3 He, from 2.1 GV to 21 GV for 4 He and from 2.1 to 15 for 3 He/ 4 He. Ø Above 4GV the 3 He/ 4 He flux ratio was found to be time independent and its rigidity dependence is well described by a single power law a R Δ with Δ =-0.295+-0.004. ∝ Ø AMS will extend the measurement of light isotopes, D, 6 Li and 7 Li toward unexplored energy range never achieved by other experiment with unprecedented precision: First measurement of D flux above 1 GeV/n and of 6 Li and 7 Li fluxes above 0.3 GeV/n. Ø Work ongoing to analyze heavier isotopes like Be. F.Giovacchini TAUP2019, Toyama 16

Ti ank you! Credits to my daughters, Arianna & Cecilia

Mass Resolution for Z=1 Tracker, Δ p/p ≈ 10% up to 20 GV ✓ ∆ p ◆ 1 ✓ ∆ β ◆ ∆ M ToF , Δβ / β 2 ≈ 4% = ⊕ (1 − β 2 ) β M p NaF : Δβ / β ≈ 0.4%, β >0.75 Aerogel : Δβ / β ≈ 0.1%, β >0.96 0.4 0.35 Δ M/M 0.3 Aerogel TOF M/M 0.25 NaF ∆ 0.2 0.15 0.1 1 10 K (GeV/n) F.Giovacchini TAUP2019, Toyama 18 n 18

3 He contamination from 4 He → 3 He Fragmentation The 4 He → 3 He fragmentation is determined from the 4 He → 3 H direct measurement within AMS 4 He Fragmentation Cr He Fragmentation Cross Sections oss Sections • 3 He and 3 H production cross sections in 4 He interactions are expected to be similar and constant above ~0.2 GeV/n 7

AMS: Identification of isotopes D mass resolution -> Template fit of mass distributions F.Giovacchini TAUP2019, Toyama F. Dimiccoli -- TIFPA 20