E408S: The structure of 212Po from 8He reactions on 208Pb Phil Walker, University of Surrey photo from Wilton Catford (2004)

NIM article 2002 data NB: 3 full-size Clovers + 1 small Clover, not close packed, 2 bad crystals; overall efficiency = 3.4% at 662 keV ~2 days of ~105 /s 8He: 208Pb(8He,4n)212Po

γ-rays: singles, doubles, triples

2004: high-power target tests peak current: 17 μA of 75 MeV/u 13C6+, i.e. 2.8 kW ~8x105 s-1 8He average over 5 days ~2x105 s-1 8He

JPG article 2004 data NB: 4 full-size Clovers, close packed, overall efficiency = 13.5% at 662 keV ~4 days of ~2x105 /s 8He: 208Pb(8He,4n)212Po improvement for γ-γ: 2x2х(13.5/3.4)2 = 60

1st and 2nd 223 keV gate 1 2002 data 223 keV gate 2 2004 data

Garnsworthy et al., J. Phys. G31 (2005) s1851 212Po 212Po levels adding to: Poletti et al., Nucl. Phys. A473 (1987) 595 partial scheme 868 keV gate

singles 981 8He singles 223 212Po 405 Energy

beamline 2.5m target detector ~35μg/cm2 beam detector problems: (i) too much beam scattering (ii) too low efficiency beamline 2.5m beam detector ~35μg/cm2 target

singles time spectra time spectra without Tref with Tref ~40 ns

New transitions assigned to 212Po. Beam timing not yet realised. Outcomes: New transitions assigned to 212Po. Beam timing not yet realised. “the day will come when thou shalt see with thine own eyes what an honourable thing it is to wander in the pursuit of this calling” Don Quixote, Cervantes, 1605

cleaning up heavy-ion,xn spectra thick target: no charged-particle reaction products 90 ns between beam pulses (cf. ~20 ns time resolution) 10 μs between beam particles, for 105 8He per second beam-particle detection is needed (or neutrons)