1 / 33

22 Na+p 共振散射的厚靶实验研究

22 Na+p 共振散射的厚靶实验研究. 王 友 宝. 原子能院核天体物理组 2013 年 RIBLL 实验计划. Contents. Scientific Motivation CRIB experiment and result RIBLL experiment. Orgueuil meteorites and Ne-E problem.

nam
Download Presentation

22 Na+p 共振散射的厚靶实验研究

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. 22Na+p 共振散射的厚靶实验研究 王 友 宝 原子能院核天体物理组 2013年RIBLL实验计划

  2. Contents • Scientific Motivation • CRIB experiment and result • RIBLL experiment

  3. Orgueuil meteorites and Ne-E problem Fell on May 14, 1864, a few minutes after 8 pm, near Orgueuil in southern France. About 20 stones fell over an area of several square miles. In 1972，Black found that in Orgueuil meteorites the abundance ratio of 20Ne/22Ne is less than 1.5，much lower than that of 9.8 on earth, this is the so-called Ne-Extraordinary problem。Geoch. Cosmochim. Acta V36, 347(1972)

  4. Presolar grains separated from meteorite SEM-Secondary electron image S. Amari, ApJ690:1424–1431, 2009

  5. 22Na production somewhere The relatively short half-life and the 1.275 MeV g-ray make the 22Na a possibly sensitive probe for the diagnosis of nearby Nova outbursts from the Sun.

  6. International Gamma-Ray Astrophysics Laboratory European Space Agency http:// www.esa.int/science/integral

  7. Milky Way seen by 26Al g-ray at satellite observatory INTEGRAL observatory total of about 2.8 solar masses of 26Al in our galaxy

  8. 22Na g-ray observation COMPTEL aboard CGRO observed five nearby Ne-type novae 22Na: only an upper limit of 3.710-8 M⊙ of ejected 22Na by any nova in the Galactic disk. What happened to the 22Na?

  9. Classic Nova Thermonuclear outburst takes place on the surface of a white dwarf component in a close binary system Joséet al., APJ, 520:347-360(1999)

  10. Main nuclear paths in the synthesis of 22Na Four reactions that control the synthesis of 22Na: 20Ne(p,g)21Na 21Ne(p,g)22Na 21Na(p,g)22Mg 22Na(p,g)23Mg Joséet al., APJ, 520:347-360(1999)

  11. Narrow resonances rate entirely determined by “resonance strength” wgand energy of the resonance ER resonance strength (= integrated cross section over resonant region) (Gi values at resonant energies) • experimental info needed • partial widths Gi • spin J • energy ER

  12. CRIB 22Na+p experiment February 28-March 10, 2012 22Na beam production conditions

  13. 22Na RIB production At F3, with 50 kV of Wien Filter Purity: ~2×46.8 %

  14. Experimental setup at F3 chamber Gas target Length: 300 mm Windows: 2.5 mm Havar (front), 26.5 mm Mylar (back). Silicon Telescopes DSSSD+SSD 5050 mm2 22Na: 37.1 MeV (in gas) 2.5×105 pps (on target)

  15. Setup for 22Na+p/a PPAC Gas target H2: 310 torr He: 400 torr Ar: 75 torr 22Na

  16. a p d Light recoils from 22Na+p Proton spectrum from 22Na(p,p) and background

  17. Excitation function of 22Na(p,p)

  18. Multi-level R- matrix analysis

  19. Paper accepted for publication in PRC

  20. ST1 22Na+a Excitation Function ST2 ds/dW /mb/sr ST3 激发能区太窄，并且发现使用气体靶会导致较大几何不确定性！ Ec.m. /MeV

  21. 22Na+p with a solid (CH2)n target 固体靶的优势 • 反应点的几何不确定性小，因此在低能段更准确。 • 能够覆盖更宽的23Mg激发能区，同时测量22Na(p,g)23Mg和19Ne(a,p)22Na感兴趣的23Mg能级。 • 比气体靶实验更简单易行。

  22. Motivations of another 22Na+p measurement • To study the relevant resonances in 23Mg over larger excitation energy region using 22Na+p channel with a well-developed thick target method • To study the 23Mg energy level related to the 19Ne(a,p)22Na reaction

  23. X-RAY BURSTERS & X-RAY PULSARS

  24. RIBLL1－低能次级束测试 参照东京大学CRIB装置，在RIBLL1上加装气体靶。 • 产生反应（逆运动学） 1H(22Ne, 22Na)n • 主束(22Ne7+) 能量：6.2 MeV/u；流强：~ 300 enA (RIBLL1入口) • 气体靶 氢气 [f30，80 毫米长，500 mbar大气压，酒精冷却～2C] • 次级束(22Na11+) • 纯度：30％，流强：1.7104 pps • 预期：1000 enA 22Ne, 1atm 氢气, 22Na流强可达 2105 pps

  25. RIBLL的22Na次级束流 • 束流粒子鉴别图 狭缝条件：C1:15 mm (DE/E=1.5%), C2: 10 mm (DE/E=1.0%) } TOF1计数率：46万每秒 TOF2计数率：7.6万每秒 T1－T2传输效率：17％ 【参见：J.J. He et al., NIMA680(2012)43-47】

  26. 22Na次级束

  27. 实验设置 22Na: 93 MeV, Ec.m.≈ 4.0 MeV (CH2)n靶： 7.5 mg/cm2

  28. 谢谢大家！

  29. Beam size on target position by extrapolation

  30. 22Na(p,g)23Mg Reaction Rate

More Related