1 / 22

B.MOUGINOT IPNO PHD director : F. AZAIEZ, S. FRANCHOO

B.MOUGINOT IPNO PHD director : F. AZAIEZ, S. FRANCHOO. Giant Pairing Vibration : Experimental Overview. How to populate a O+ state in Nuclei ?. Giant Pairing Vibration. GPV Mode : Collective Excitation of Pair in the Next Major Shell. Next Major Shell. Low-lying 0+ Excitation.

hector-dominguez
Download Presentation

B.MOUGINOT IPNO PHD director : F. AZAIEZ, S. FRANCHOO

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. B.MOUGINOT IPNO PHD director : F. AZAIEZ, S. FRANCHOO Giant Pairing Vibration : Experimental Overview

  2. How to populate a O+ state in Nuclei ? Giant Pairing Vibration GPV Mode : Collective Excitation of Pair in the Next Major Shell Next Major Shell Low-lying 0+ Excitation First 0+ excited state A Higher excited 0+ Ground State 0+

  3. Giant Pairing Vibrations GPV is a Collective mode GPV >Pairing vibrations : L=0 >Sensitive to Pairing interaction > Should lie at high excitation energy > 2 nucleon transfer channel selective for pairing vibration ex (p,t) reaction E. Khan PRC69(2004)

  4. Overview of (p,t) reactions 208Pb (p,t) 206Pb 51.9MeV protons at Institute of Nuclear Study Data recorded at 8°- 65° E* range : 0 - 10 MeV Orihara Phys.Rev. C 9(1974)266 35MeV protons at MSU cyclotron : Data recorded at 6° 14° 30° E* range : 0 - 7 MeV Lanford Phys.Rev. C 16(1977)988

  5. 208Pb (p,t) 206Pb 40 MeV protons at Indiana University Cyclotron (IUCF)‏ Position sensitive chamber at the focal plane of the spectrograph >Data recorded at 7°- 35° E* range : 0 - 5 MeV Shepard Nucl.Phys. A 322(1979)‏ 51.9 MeV protons at Institute of Nuclear Study Tokyo University Array of 200 proportional counters at the focal plane of the spectrometer >Data recorded at 2°- 60° E* range : 0 - 6 MeV Takahashi Phys.Rev.C 27(1983)‏

  6. 208Pb (p,t) 206Pb 168 MeV protonsat K220 Orsay Synchrocyclotron Data recorded at 2°- 18° E* range : 0 - 12 MeV Gerlic Phys.Rev. C 39(1989)‏ 120 MeV protons at IUCF Vertical-wire Drift Chamber at focal plane of K600 spectrometer Data recorded at 7°- 34° E* range : 0 - 7 MeV Mihailidis Phys.Rev.C 64(2001)‏

  7. 120Sn (p,t) 118Sn 40 MeV protons at University of Minnesota linear accelerator 8 Plastic scintillators at the focal plane of the spectrometer E* range : 0 - 11 MeV Data recorded at 7°-30° Bassani Phys.Rev. 139(1965)‏

  8. 0 250 0 120,122Sn (p,t) 118,120Sn E* range : 0 - 20 MeV 42 MeV protons at Jefferson lab resistive-wire proportional counter at focal plane of Enge spectrometer Data recorded at 10°- 45° Crawley et al. Phys.Rev.Lett. 39(1977)33 89MeV protons at IUCF Data recorded at 15°- 45° E* range : 0 - 50 MeV Crawley et al. Phys.Rev. C 22(1980)‏

  9. Why revisit (p,t) reactions for GPV? On 208Pb : >51.9 MeV proton at 8°- 65°:Orihara Phys.Rev. C 9(1974)266 >35 MeV proton at 6° 18° 30° :Lanford Phys.Rev. C 16(1977)988 >40 MeV proton at 7°- 35° : Shepard Nucl.Phys. A 322(1979)‏ >51.9 MeV proton at 6° 18° 30° : Takahashi Phys.Rev.C 27(1983)‏ >168 MeV proton at 2°-18° : Gerlic Phys.Rev. C 39(1989)‏ >120 MeV proton at 7°-34° : Mihailidis Phys.Rev.C 64(2001)‏ GPV predicted at 10-20MeV >wrong Energy Range On 120Sn : >40 MeV proton at 7°- 30° : Bassani Phys.Rev. 139(1965)‏ >42 MeV proton at 10°- 45° : Crawley et al. Phys.Rev.Let. 39(1977)33 >89MeV proton at 15°- 45°: Crawley et al. Phys.Rev. C 22(1980)‏ No experiment at the right angle and/or the right energy !! 0°or very near 0°& 60 MeV

  10. Our recent work At iThemba (South-Africa) : 208Pb(p,t)206Pb Q = -5.62 MeV 120Sn(p,t)118Sn Q = -7.111 MeV Spectrometer at 7°

  11. Our recent work p (208Pb,206Pb) t & p (120Sn,118Sn) t Target : 208Pb & 120Sn Proton beam At 60 MeV tritons 2 Week-ends B Spectrometer at 7° Selection of B window (5-7MeV)‏ 1 Wire Chamber : position of the light ejectile - triton energy 1 Paddle : dE/TOF – triton selection thickness 6.4mm

  12. 7/2- 5/2- Without Gate 3/2- 208Pb(p,d)207Pb Ground State 13/2+ Gate on Deuterons E paddle1 12C(p,t)‏ Gate on Tritons TOF 16O(p,t)‏ triton deuteron Exemple for 41MeV setting

  13. No gate: Tritons acceptance ratio : Deuterons acceptance ratio : E paddle1 gated on tritons: 12C(p,t)‏ 16O(p,t)‏ TOF Exemple for 41MeV setting

  14. Excitation Spectrum of 206Pb all fields overlapping

  15. Excitation Spectrum of 206Pb all fields superimposed Excited state of 207Pb Excited state of 206Pb 10C Ground state 14O Ground state So far no indication of bump or broad structure in the 206Pb spectrum

  16. Excitation Spectrum of 120Sn all fields overlapping

  17. N=70 Deephole states Excitation Spectrum of120Sn(p,t) : A hint for GPV in 120Sn: observation of cross-section enhancement (weak bump) at Ex=12MeV? The GPV? If yes, should increase at 0° GPV? Next Move :in SPRING 2009 120Sn(p,t)118Sn & 208Pb(p,t)206Pb proton beam @ 60 MeV K600 spectrometer @0°

  18. Futur plans and improvments? Thank you iThemba labs

  19. N=70 Deephole states Excitation Spectrum of1118Sn(p,t) : A hint for GPV in 120Sn: observation of cross-section enhancement (weak bump) at Ex=12MeV? The GPV? If yes, should increase at 0° GPV?

  20. GPV could be searched for using Pair Transfer Reactions (t,p) reactions (p,t) reactions

  21. Futur plans and improvments? At iThemba : 208Pb(p,t)206Pb Q = -5.62 MeV 120Sn(p,t)118Sn Q = -7.111 MeV GPV : L = 0 pairing mode Spectrometer at 0°

More Related