Study of two neutron transfer reaction and resonant

Study of two neutron transfer reaction and resonant elastic scattering induced by 11 Li, with the MAYA active target. Seminar ISOLDE 06/10/10 -1 -

Outline 1. MAYA@TRIUMF : Transfer & resonant reactions with 11 Li - Motivations - The active target MAYA - The TRIUMF experiment 2. MAYA@ISOLDE : Possible experiments - Technical issues - Possibilities Seminar ISOLDE 06/10/10 -2 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE • Halo occurrence condition(s) low binding energy low angular momentum (1) • N=7 parity inversion 10 Li (G. S. ) : s-state (2) s-p mixing in 11 Li (3) • 11 Li coulomb dissociation strong correlations K. Riisager et al. , Nucl. Phys. A 548, 393 (1992) H. Simon et. al. , Nucl. Phys. A 791, 267 (2007) (3) H. Simon et. al. , Phys. Rev. Lett. 83, 496 (1999) (4) T. Nakamura et. al. , Phys. Rev. Lett. 96, 252502 (2006) (1) (2) Seminar ISOLDE 06/10/10 -3 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE Study of “low energy” reactions induced by 11 Li on a proton target - 2 neutron transfer reaction. angular distribution : strength of the correlation - 1 neutron transfer reaction. angular distribution : spectroscopy of the halo. - Elastic scattering. angular distribution : density distribution Reactions with losely bound nucleus at low energy - Resonant elastic scattering. excitation function : 12 Li Isobaric Analog States Couplings! N. Keeley and V. Lapoux, Phys. Rev. Lett. 77, 014605 (2008) A. Lemasson et al. , accepted in Phys Rev. C Seminar ISOLDE 06/10/10 -4 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE Study of “low energy” reactions induced by 11 Li on a proton target - 2 neutron transfer reaction. angular distribution : strength of the correlation - 1 neutron transfer reaction. angular distribution : spectroscopy of the halo. Good angular coverage - Elastic scattering. angular distribution : density distribution - Resonant elastic scattering. excitation function : 12 Li Isobaric Analog States + Thick target Active target (detection/ reaction ) Seminar ISOLDE 06/10/10 -5 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE ISAC II up to 5000 pps 11 Li @ 5 A Me. V 0° beamline with PPAC detector and the active target MAYA Seminar ISOLDE 06/10/10 -6 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE C. E. Demonchy et al. , Nucl. Instrum. Methods A 573, 145 (2007) Seminar ISOLDE 06/10/10 -7 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE A two dimensional charge – one dimensional time projection chamber Cathode recorded pattern 2 dimensions Wire recorded time 3 rd dimension Seminar ISOLDE 06/10/10 -8 -

Motivations Experimental setup Results Light particles + high energy Si / Cs. I 2 solid identification stages + 1 gaseous stage Conclusion MAYA@ISOLDE Medium energy PADS / Si Large identification dynamics! Seminar ISOLDE 06/10/10 -9 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE Charge distribution : “ The recorded charge distribution is the result of the convolution of the charge distribution created by a point-source and the hexagonal geometry of the pads, all along the charged particles tracks and weighted by their energy losses. ” YMAYA (mm) A simulation is necessary to develop the reconstruction algorithms and to estimate the geometric efficiency 160 80 0 90 180 Seminar ISOLDE 06/10/10 Depth (mm) - 10 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE Two experiments – Two setups “Thin” target : fixed energy “Thick” target : fixed c. m. angle (670 mbar – 7. 6 mg/cm 2) (150 mbar - 1. 7 mg/cm 2) excitation functions angular distributions angle-angle correlations energy-energy correlations Seminar ISOLDE 06/10/10 - 11 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE Mass measurement by Q-value measurement : 1 H(11 Li, 9 Li)t corrélations énergie-énergie corrélations angle-angle S 2 n (11 Li) = 363(22) ke. V T. Roger et al. , Phys. Rev. C 79, 031603(R) (2009) Can be extended to unbound nuclei Seminar ISOLDE 06/10/10 - 12 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE Angular distribution @ 4. 3 A Me. V - Very close to Rutherford unusual behavior (qgrazing = 10°) - Global Optical Potentials : Fail! Need to increase Wd et diminish awd Surface peaked absorption! (breakup + transfer, compound nucleus) Seminar ISOLDE 06/10/10 - 13 -

Motivations Experimental setup Results Conclusion 3 A Me. V MAYA@ISOLDE 4. 3 A Me. V transitions to 9 Li (GS) & 9 Li* (2. 69 Me. V) DWBA/CRC calculation required Seminar ISOLDE 06/10/10 - 14 -

Motivations Experimental setup Results Conclusion CCBA calculations (I. J. Thompson) 11 Li: s 2 & p 2 10 Li MAYA@ISOLDE E 11 G. S. Rm rms (s 1/2)2 wt (p 1/2)2 wt (Me. V) (fm) (%) p sequential P 0 -0. 33 3. 05 3 94 s P 2 -0. 32 3. 39 31 64 P 3 0. 33 3. 64 45 51 simultaneous 9 Li (g. s. ) I. J. Thompson et al. (Phys. Rev. C 49, 1904 (1994)) 3 A Me. V 4. 3 A Me. V I. Tanihata et al. , Phys. Rev. Lett. 100, 192502 (2008) Configuration mixing! Seminar ISOLDE 06/10/10 - 15 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE Angular distribution @ 4. 3 A Me. V (integrated over 10 Li states) Contribution of 9 Li(cont. ) (minor) Hard to identify the populated CRC state calculation needed! Seminar ISOLDE 06/10/10 - 16 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE Kinematics reconstruction with the energy/energy (range) correlations VERTEX TOTAL PATH BEAM HEAVY VERTEX TOTAL PATH Seminar ISOLDE 06/10/10 - 17 -

Motivations Experimental setup Results Conclusion 150° cm MAYA@ISOLDE 175° cm Resonance @ Ecm ≈ 3 Me. V Possible IAS of 12 Li (T=3 state observed in 12 Be: Charity et al. ) R. J. Charity et al. , Phys. Rev. C 76, 064313 (2007) R matrix calculation to assign a spin Seminar ISOLDE 06/10/10 - 18 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE R-Matrix calculations • E < 2 Me. V Rutherford • Hard sphere phase shifts Cross section too high 1 level approximation not valid Complex phase shifts VB 11 Li+p optical potential needed! All the processes are interconnected! Seminar ISOLDE 06/10/10 - 19 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE Breit Wigner fit: Incoherent sum of Coulomb et BW Er = 3. 0 Me. V Gtot = 1. 1 Me. V Seminar ISOLDE 06/10/10 - 20 -

Motivations Experimental setup Our result: Results Conclusion MAYA@ISOLDE Y. Aksyutina : s state @ 1. 5 Me. V Er = 3. 0 Me. V Gtot = 1. 1 Me. V Y. Aksyutina et al. , Phys. Lett. B 666, 430 (2008) Gsp @ 3 Me. V: l = 0 : 7. 58 Me. V No positive parity states l = 1 : 5. 28 Me. V below 6. 5 Me. V (E*=3. 5 Me. V) l = 2 : 1. 91 Me. V + B. A. Brown, Private Communication s state with S = 0. 14 = d state with S = 0. 57 d state compatible with CXMSM calculations (Z. X Xu et al. submitted to Phys. Rev. C) Seminar ISOLDE 06/10/10 - 21 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE + Elastic scattering angular distribution. ≈ Rutherford up to 90° cm: coupling to transfer and breakup channels + 1 n and 2 n transfer angular distributions @ 3 A and 4. 3 A Me. V First calculations indicate a strong correlation between the halo-neutrons + Mass of 11 Li by Q-value measurement + 11 Li(p, p)11 Li excitation function at 150° and 175° cm possible T=3 state in 12 Be Interconnected processes! Need global treatment with CRC & CDCC Complete study - ideal study with active targets - ideal case for Coupled Reaction Channel calculations Seminar ISOLDE 06/10/10 - 22 -

MAYA@TRIUMF Collaborators T. Roger , H. Savajols, M. Caamaño, P. Roussel-Chomaz GANIL, Bd Henri Becquerel, BP 55027, 14076 Caen Cedex 05, France W. Mittig and H. Wang NSCL, MSU, East Lansing, MI 48824 -1321, USA I. Tanihata, M. Alcorta, D. Bandyopadhyay, R. Bieri, L. Buchmann, B. Davids, N. Galinski, D. Howell, W. Mills, R. Openshaw, E. Padilla-Rodal, G. Ruprecht, G. Sheffer, A. C. Shotter, M. Subramanian, M. Trinczek, and P. Walden TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V 6 T 2 A 3, Canada R. Kanungo and A. Gallant Saint Mary’s University, 923 Robie St. , Halifax, Nova Scotia B 3 H 3 C 3, Canada M. Notani and G. Savard ANL, 9700 S. Cass Ave. , Argonne, IL 60439, USA I. J. Thompson LLNL, L-414, P. O. Box 808, Livermore CA 94551, USA ++ MAYA’s Technical Staff as : J. F. Libin, P. Gangnant, C. Spitaels, L. Olivier & G. Lebertre Seminar ISOLDE 06/10/10 - 23 -

MAYA@ISOLDE: possible experiments Seminar ISOLDE 06/10/10 - 24 -

Motivations Experimental setup Results - MAYA: slow gazeous detector Conclusion MAYA@ISOLDE Pile-up above 1 ion/10 µs - MAYA dynamics from p(11 Li, 9 Li)t @ 4. 3 A Me. V – 150 mbar C 4 H 10 CM = 35° E 9 Li = 53. 9 Me. V Et = 1. 4 Me. V <d. E/dx>9 Li = 26 ke. V/mm CM = 145° E 9 Li = 19. 1 Me. V Et = 36. 3 Me. V <d. E/dx>t = 1. 5 ke. V/mm Dynamics ≈ 20 Upgrade of GASSIPEX : threshold 100 m. V 30 m. V Seminar ISOLDE 06/10/10 - 25 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE Possible solution : mask the beam Transparency tunable (0 – 10%) Artificially increases the dynamics E. Kahn, J. Gibelin E 548 a (GANIL): 68 Ni(d, d’) dynamics ≈ 100 Seminar ISOLDE 06/10/10 - 26 -

Motivations Experimental setup Results Conclusion MAYA@ISOLDE Pulsed beam from EBIS : Instantaneous maximum intensity! if Ipps>103 : on 1 µs Imax ≈ 103 Ipps If the beam track is needed: (resonant reaction, precise transfer reactions) limited to 102 – 103 pps Else: theoretically no restriction BUT: 132 Sn beam @ 105 pps into 150 mbar C 4 H 10 : 1. 7 x 107 e- /mm/1µs Very close to the sparking limit… Seminar ISOLDE 06/10/10 - 27 -