Proton emission from deformed rare earth nuclei Robert Page

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