1 / 10

Search for low spin states at high excitation energies in 20 Ne with the p,t reaction

Search for low spin states at high excitation energies in 20 Ne with the p,t reaction. iThemba LABS & Stellenbosch University. Energy Postgraduate Conference 2013. Alpha clustering in n-alpha nuclei. Threshold rule : n-alpha cluster state

lorna
Download Presentation

Search for low spin states at high excitation energies in 20 Ne with the p,t reaction

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. Search for low spin states at high excitation energies in 20Ne with the p,t reaction iThemba LABS & Stellenbosch University Energy Postgraduate Conference 2013

  2. Alpha clustering in n-alpha nuclei • Threshold rule: n-alpha cluster state expected above n-alpha breakup threshold in all n-alpha nuclei e.g. 8Be, 12C • Want to find 5 alpha cluster state in 20Ne • To use 22Ne(p,t)20Ne reaction with K600 magnetic spectrometer

  3. The iThemba LABS cyclotron For 4 weekends from April to July 2012: • Proton beam delivered from SPC1 through K line to SSC • Accelerated to 60 MeV by SSC • Steered through X, P1, P2 and S lines to K600 vault

  4. Experimental tool: The K600 spectrometer K600 contains: 1 Quadrupole, 2 dipoles, H- and K-coil (focussing magnets) Best (p,p') resolution: 25 keV Best (α,α') resolution: ~50 keV (for 200 MeV beams)

  5. Experimental tool: The 22Ne gas target Cell enclosed between two 6 micron Aramid windows containing gas • Entrance area: 1⨯3 cm2 • Target 1 cm thick • Gas target was used before with K600 during experiment in 2009...

  6. Preliminary data 22Ne(p,t)20Ne at 0° Red – 33.5 MeV Green – 36 MeV Orange – 41 MeV Blue – 46 MeV Magenta – 52 MeV Black – Aramid background Counts/ 10 keV Excitation energy [MeV]

  7. Preliminary data 22Ne(p,t)20Ne at 0° Blue – 33.5 MeV Red – 36 MeV Black – Aramid background Candidate isobaric analogue states Counts/ 10 keV 5-alpha prediction - PRC 69 024309 (2004) Excitation energy [MeV]

  8. Preliminary data Angular distribution of Isobaric Analogue candidates Angular distribution of known states

  9. Interpretation of the new states Prediction from Werner Richter's IMME calculation for strong isobaric analogue candidates: Calculations for T=2 states 20.59 MeV 20Ne - 3.856 MeV 20O 21.168 MeV 20Ne – 4.435 MeV 20O 21.796 MeV 20Ne – 5.063 MeV 20O Known in 20O 3.570 MeV 4+20O 4.072 MeV 2+20O 4.456 MeV 0+20O 4.850 MeV 4+20O 5.002 MeV 20O 5.234 MeV 2+20O

  10. Interpretation of the new states Prediction by Alex Brown using NuShellX and Fresco: Experimental cross sections from present measurement at θLAB=0∘:

More Related