1 / 24

The Lifetime Measurement of First 2 + State in 174 Os with LaBr 3 (Ce)

The Lifetime Measurement of First 2 + State in 174 Os with LaBr 3 (Ce). 李聪博 1,2 等 指导教师：吴晓光 1 ，李险峰 2 1 中国原子能科学研究院 2 吉林大学. 2012-4-13 浙江湖州. CONTENTS. Introduction LaBr 3 :Ce Crystals and Test Experimental Electronics and Data analysis method Off-line Test with 152 Eu

fagan
Download Presentation

The Lifetime Measurement of First 2 + State in 174 Os with LaBr 3 (Ce)

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. The Lifetime Measurement of First 2+ State in 174Os with LaBr3(Ce) 李聪博1,2 等 指导教师：吴晓光1，李险峰2 1中国原子能科学研究院 2吉林大学 2012-4-13浙江湖州

  2. CONTENTS • Introduction • LaBr3:Ce Crystalsand Test • Experimental Electronics and Data analysis method • Off-line Test with 152Eu • In-beam Experiments • Conclusions

  3. Introduction Os 174Os Neutron mid-shell A Large error bar

  4. Introduction • Recoil distance method (RDM) with Plunger devices. (ps - ~1ns) • Triple-βγγ (t) coincidence method using a mix of Ge, plastic, BaF2 or LaBr3(Ce) in β decay experiment. (>several Ps) H. Mach et al, Nucl. Instrum. Meth. A 280, 49 (1989). • 3. A new experimental method Triple-γγγ (t) with LaBr3(Ce) and Ge in-beam experiments. (>several Ps) N. Mărginean, et al., Eur.Phys.J.A 46,329(2010) 174Os(21+) with lifetime 505(60) ps (RDM). J. Gascon et al., Nucl. Phys. A 470, 230 (1987).

  5. LaBr3:Ce Crystalsand Test

  6. LaBr3:Ce Crystalsand Test Crystals characteristics Volume: Four 30 × 30mm Three 1 × 1 inch cylinder

  7. LaBr3:Ce Crystalsand Test Energy Resolution

  8. LaBr3:Ce Crystalsand Test Time Resolution 22Na

  9. Experimental Electronics and Data analysis method

  10. Experimental Electronics and Data analysis method Sloping method H. Mach, R.L. Gill and M.Moszyinski, Nucl. Instrum. Meth. A 280, 49 (1989).

  11. Off-line Test with 152Eu

  12. Off-line Test with 152Eu Deconvolution Fitting 1.39（3）ns T1/2=1.42(2)ns

  13. In-beam Experiments

  14. In-beam Experiments Cascade

  15. In-beam Experiments • Beams: 140 MeV 28Si • Target: 0.9mg/cm2152Sm rolled onto a12.5mg/cm2 Pb backing • 10 HPGe-BGO , 2 Planar HPGe and 7 LaBr3(Ce)

  16. In-beam Experiments J.L. DURELL et al. Phys. Letter. B115 367(1982)

  17. In-beam Experiments 508(16)ps

  18. In-beam Experiments Jing-ye Zhang et al., Phys. Rev. C 73, 037301 (2006)

  19. In-beam Experiments A large increase A subshell structure in the evolution of W and Os isotopic chains. M. Rudigier et al., Nucl. Phys. A 847, 89 (2010).

  20. In-beam Experiments N.V. Zamfir et al. Phys. Letter. B357 515(1995) P.Moller,J.R.Nix,W.D.Myers,W.J.Swiatecki,At.DataNucl.DataTables59(1995)185–381.

  21. In-beam Experiments

  22. In-beam Experiments Suggested as +0.117 +0.145 P.Moller,J.R.Nix,W.D.Myers,W.J.Swiatecki,At.DataNucl.DataTables59(1995)185–381. M. Rudigier et al., Nucl. Phys. A 847, 89 (2010).

  23. Conclusions • The lifetime of the first excited 2+ state in 174Os has been remeasured in fast time experiment and determined to be a greater accuracy, to be 508(16)ps. • A deviation of the B(E2) value systematics in 174Os may hint a nuclear structure change, resulting a large increase in hexadecapole deformation (with +0.145). • These explanations, from phenomenology at least, modify the expected trends. Other explanations, especially with microscopic model calculations, are needed.

  24. Thanks for your attention!

More Related