Proton emission from deformed rare earth nuclei

Robert Page

Simple model for spherical proton emitters

pprotonp S1A

AEQ

Proton decay of 160Re

Qp = 1271 keV

AREA2/1 et

160Re Half-life (ms)

Ep (keV) d3/2 h11/2 Expt

1263 0.24 480 0.67

h11/2

d3/2)(t

)calc(tS

2/1

2/1

expt

Proton emission as a spectroscopic tool

Deformed proton emitters

P.J. Woods et al., PRC69 (2004) 051302

135Tb

Known Proton Emitters

B. Blank & M.J.G. Borge, Progress in Particle and Nuclear Physics 60 (2008) 403

Known Proton Emitters

B. Blank & M.J.G. Borge, Progress in Particle and Nuclear Physics 60 (2008) 403

SelectivityYield

Why are there so few knownproton emitters in this region?

Implantation – proton – alpha correlation

Decay Particle Energy (MeV)

Coun

ts (

106 )

/ 10

keV

Coun

ts /

10

keV

Decay Particle Energy (MeV)

t1/2 = 21 s

The proton emitter 159Re

D.T. Joss et al., Physics Letters B641 (2006) 34

Implantation – proton correlations

P.J. Woods et al., PRC69 (2004) 051302

50Cr + 92Mo → 135Tb + p6n

Argonne FMA

A = 135 only

60 m thick DSSD

Beta-decay half-lives

Moller, Nix & Kratz, Atomic Data & Nuclear Data Tables 66 (1997) 131

Proton-decay half-lives

Fusion-evaporation reactions

Compound nuclei

Fusion-evaporation pxn reactions

30 b

3 nb

(Super-)FRS A & Z separation

Isomer decays or known pfor unique A & Z identification

AIDA

Selectivity

Predicted Super FRS Yields @ 1012/s

Neutron number N

Atom

ic n

umbe

r Z

= 3.6 / hour= 0.6 / week

Yield

Predicted Super FRS Yields @ 1012/s

Neutron number N

Atom

ic n

umbe

r Z

= 3.6 / hour= 0.6 / week

Yield

Some physics opportunities

• New proton emitters• Weak proton-decay branches• Proton-decay fine structure• Precision measurements• Beta-delayed gamma spectroscopy

Outstanding questions

• Background from and p decays(1 mm thick DSSDs cf. 60 m)

• Identify best physics cases• Choose best primary beam

Your input is welcome...

Robert Page