ISOMERIC BEAMS

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ISOMERIC BEAMS. Phil Walker University of Surrey. Shell-model isomers in the 208 Pb region Stopped isomeric beams: < 1 ms Stopped isomeric beams: > 1 ms Fast isomeric beams: purification Fast isomeric beams: reactions. 212 Po = 208 Pb + . 2911 keV, (18+) = 65 s , decay. - PowerPoint PPT Presentation

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  • ISOMERIC BEAMSShell-model isomers in the 208Pb regionStopped isomeric beams: < 1 msStopped isomeric beams: > 1 msFast isomeric beams: purificationFast isomeric beams: reactionsPhil Walker University of Surrey

  • 212Po = 208Pb + 2911 keV, (18+) = 65 s, decayground state, 0+, 430 ns, decaywait for one second: isomer purity = 100 %

  • E > 1MeV, > 1 ms isomersWalker and Dracoulis, Nature 399 (1999) 35

  • high-spin isomer charta Phil Walker special

  • long-lived, high-spin isomersWalker and Dracoulis, Hyp. Int. 135 (2001) 83

  • hafnium (Z=72) isomersWalker and Dracoulis, Hyp. Int. 135 (2001) 83178Hf 188Hfexpt.calc.

  • Super-FRS yields215Ra

  • 215RaStuchbery et al.Nucl. Phys. A641 (1998) 401 = 800 ns, 43/2-, 3.8 MeV407 keV -rayfrom 206Pb(13C,4n)

  • 215Ra -ray spectrumfrom 238U fragmentationZ. Podolyak, private communication

  • 217Ac level schemefrom (HI,xn) reactionsDecman et al., Nucl Phys. A436 (1985) 31129/2+, T1/2 = 740ns217Ac

  • 217Ac -ray spectrumZ. Podolyak, private communicationfrom 238U fragmentation

  • 208Pb regionmany s isomersexpected212Po, 18+, 65s215Ra, 43/2-, 800ns217Ac, 29/2+, 1s

  • Summary217Ac: 1s isomer purified by flight time through FRS (factor of 15 in 300 ns) good for RISING fast beam opportunity for (i) -gated Coulex (ii) knockout reactions and knockout to other isomers: RISING stopped beam

    212Po: 65s isomer 100 % purified by flight time in ESR

    N~126, Z