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

2. 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

3. γ-rays: singles, doubles, triples

4. 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

5. 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

6. 1st and 2nd 223 keV gate 1
2002 data
223 keV gate 2
2004 data

7. 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

8. singles
981 8He
singles
223
212Po
405
Energy

9. 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

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

11. 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

12. 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)