1 / 22

Feb. 2003

50 分 => Talk なら 35 枚だが、 lecture だと少なめ？. Feb. 2003. Nuclear-structure studies with fast exotic beams. Tohru Motobayashi (RIKEN). Ring Cyclotron (1987) + RIPS (~1990) - RIKEN fast exotic beam or RI beam by projectile fragmentation v/c ~ 0.3 (40-90 MeV/nucleon)

africa
Télécharger la présentation

Feb. 2003

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. 50 分 => Talk なら 35 枚だが、lecture だと少なめ？ Feb. 2003 CNS Summer School

  2. Nuclear-structure studies with fast exotic beams Tohru Motobayashi (RIKEN) Ring Cyclotron (1987) + RIPS (~1990) - RIKEN fast exotic beam or RI beam by projectile fragmentation v/c ~ 0.3 (40-90 MeV/nucleon) c.f. RIBF => 200-300 MeV/nucleon, wide range of nucl. “In-beam”g- and particle spectroscopy => nuclear structure of unstable nuclei magicity loss in n-rich nuclei with N=8, 20 => reactions involved in (explosive) nuclear burning solar neutrino production, novae burning CNS Summer School

  3. RIKEN Accelerator Research Facility and RI Beam Factory Project 135 MeV/nucleon for light nuclei 0 350 MeV/nucleon up to U 1 2 1st beam in 2006 under consideration CNS Summer School

  4. Coulomb excitation of N = 20 nuclei Disappearance of the sd-pf shell gap for 32Mg and 30Ne MSU RIKEN CNS Summer School

  5. 1+ (M1) Solar neutrino production Coulomb dissociation of 8B RIKEN-2 (98) RIKEN-I (94) C.D.: insensitive to M1 resonance CNS Summer School

  6. How can we study nuclear structures with fast Radio-isotope (RI) beams ? 1) Direct reactions for nuclear-structure studies 2) RI beams of fragmentation scheme 3) Inverse kinematics 4) Two methods of spectroscopy Doppler-shifted g-rays Particle decays from unbound states 5) Some examples CNS Summer School

  7. direct reaction => nuclear structure information E PID q bam = probe target = object examples: (p,p’), (d,p), … reaction channel: PID of ejectile excited level: E (q) cross section => deformation single particle strength angular distribution => angular momentum direct (first-order) mechanism CNS Summer School

  8. 58Ni(d,p)59Ni E =15 MeV (1962) 4 distance along the focal plane (momentum) 2 3 l- dependence of angular distribution 1 0 CNS Summer School

  9. projectile fragmentation projectile ~ 0 v~ vbeam target by Ong Hooi Jin wide range of (unstable) nuclei regardless of chemical properties E > 50 MeV/nucleon CNS Summer School

  10. inverse kinematics / methods of spectroscopy RI (beam) + target (probe) -----> projectile-like products g decays (bound) particle decays (unbound) ------> target-like products recoil particles target-g reaction-channel ID: PID of the projectile-like product state ID: g ray (Doppler-shifted) invariant mass reaction: inelastic (Couex, C.D., (p,p’) … cex, fratmentation, knockout transfer CNS Summer School

  11. Advantage / disadvantage of fast RI beams poor (intensity) 0.1 - 105 pps dirty (emittance) 2cm f, 1~2 deg. Spread high energy efficient setups good reactions (large s) g-ray measurement invariant mass thick targets forward focusing CNS Summer School

  12. Detector arrays CNS Summer School

  13. 300 pps CNS Summer School

  14. Coulomb excitation of N = 20 nuclei Disappearance of the sd-pf shell gap for 32Mg and 30Ne MSU RIKEN CNS Summer School

  15. Locations of 2+ / 4+ states of n-rich around N=20 - “Island of inversion” - 34Mg (Z=12, N=22) Fragmentation of 36Si (2x104 cps) 30Ne (Z=10, N=20) proton inelastic 30Ne (0.2 cps) 2+ 2+ 4+ Yoneda et al., Phys. Lett. B566 (2003)84 Yanagisawa et al., Phys. Lett. B566 (2003)84 CNS Summer School

  16. 34Si + 2H -> 34Si + g + X (2x104 cps) (Z=14, N=20) g-g coincidence counts 34Si Gate: 2+ - 0+ : newly assigned CNS Summer School Iwasa et al., Phys. Rev. C67 (2003) 064315

  17. 8B Coulomb dissociation 50 - 90 MeV/nucleon DALI (208Pb) DALI HODO CNS Summer School

  18. Coulomb dissociation 7 B e Virtual photons p c.f. Nakamura halo nuclei 8 B = Coulomb excitation to unbound states c.f. Mueller, Mueller, … spectroscopy 2 0 8 P b 8B+208Pb -> 7Be+p+208Pb (C.D.) virtual photon theory or DWBA 8B(g,p)7Be (abs.) detailed balance 7Be(p,g)8B (capt.) large s thick target (intermediate energy) experiments with R.I. beams CNS Summer School

  19. Large yield detailed balance virtual photon number (intermediate energy) thick target charged particle detection indirect i.e.nucl. force / higher order / E2 100 ~ 1000 100 ~ 1000 but CNS Summer School

  20. kinematics Erel <= pp, p7Be, qp-Be DErel : Independent of DEin p+X, T0=100 AMeV, Erel=1 MeV, Dq=0.5 deg.Dv=1% DErel=200 keV CNS Summer School

  21. 1+ (M1) Solar neutrino production Coulomb dissociation of 8B RIKEN-2 (98) RIKEN-I (94) C.D.: insensitive to M1 resonance CNS Summer School

  22. spectroscopy with fast exotic beams RI (beam) + target (probe) - inverse kinematics -----> projectile-like products g decays (bound) particle decays (unbound) ------> target-like products recoil particles target-g reaction-channel ID: PID of the projectile-like product good state ID: g ray (Doppler-correction) invariant mass reaction w. large s: inelastic (Couex, C.D., (p,p’) … cex, fratmentation, knockout transfer forward focusing,thick target, efficient detectors => CNS Summer School

More Related