1. Study of 13Be through isobaric analog resonances
Motivation
13Be
Method
Feasibility
Study of 13Be through isobaric analog resonances
in the Maya active target
Riccardo Raabe (IKS, K.U.Leuven)
IKS, K.U.Leuven
IEM-CSIC, Madrid
Univ. Santiago de Compostela
GANIL, Caen
Univ. Birmingham
Univ. Aarhus
LPC-ENSICAEN, Caen
Chalmers University, Göteborg
NSCL-MSU, East Lansing
CEA Saclay
IPN Orsay
R. Raabe, T. Roger, S. Sambi
M.J.G. Borge, E. Nácher, O. Tengblad
M. Caamaño, D. Cortina-Gil, B. Fernandez-Dominguez
F. De Oliveira Santos, G.F. Grinyer, H. Savajols
M. Freer
H.O.U. Fynbo, J.S. Johansen, K. Riisager
J. Gibelin, M. Marques, N. Orr
A. Heinz, B. Jonson, T. Nilsson, G. Nyman
W. Mittig, H. Wang
E. Pollacco, P. Roussel-Chomaz
M. Vandebrouck

2. Shell ordering around N = 8
Motivation
13Be
Method
Feasibility
Shell ordering around N = 8
O. Sorlin, M.-G. Porquet Prog. Part. Nuc. Phys. 61 (2008) 602
Protons removed from p shells  reduction of N = 8
s shell available  halo nuclei 11Be, 11Li, 14Be
13Be: one neutron above N = 8 essential to model the 2-n halo nucleus 14Be
p1/2
p3/2
s1/2 π ν 8
d5/2

3. 13Be studies (exp) G. Blanchon at al. (2010) Inversion p1/2 – s1/2 ?
Motivation
13Be
Method
Feasibility
13Be studies (exp)
Korsheninnikov 1995 6
Belozyorov 1998
Simon 2007
Ostrowski 1992
Christian 2008
Kondo 2010
Lecouey 2004 4
Thoennessen 2000
1/2−
E(12Be-n) (MeV)
5/2+
(5/2+)
5/2+
5/2+
5/2+ 2
(5/2+)
1/2+
1/2−
(1/2) s
(s, 1/2+)
1/2+ s
G. Blanchon at al. (2010)
Inversion p1/2 – s1/2 ?
Necessary to reproduce 14Be (?)

4. Method: resonant scattering in a thick target
Motivation
13Be
Method
Feasibility
Method: resonant scattering in a thick target
AZ beam, Ecm scan in the target Population of resonant states in the A+1Z+1 compound nucleus isobaric analogues (IAS) of the states of interest in A+1Z
All states populated Elastic: large cross section Spin-parity assignment
12Be + p → 13B IAS of states in 13Be p
ΔE-E
Ec.m.

5. Measurement with the Maya active target
Motivation
13Be
Method
Feasibility
Measurement with the Maya active target
Usually: p at small angles limited statistics
In Maya:
Elastic scattering Detection of proton Range of beam-like particle  identification inelastic channels  larger statistics  resolution <10 keV
Detection of n-emission channel via identification of 12B p
ΔE-E
Ec.m.
T. Roger, L. Gaudefroy, W. Mittig, H. Wang, et al.
T. Roger, L. Gaudefroy, W. Mittig, H. Wang, et al.

6. Motivation
13Be
Method
Feasibility
Feasibility
12Be at 3 MeV/nucleon, min 20 pps (limit on instantaneous rate)
Maya filled with C4H10 at ≈100 mbar
50-keV bin (1019 protons/cm2) 0.5 cts/h
Production (target...)
12C contamination
12Be(p,n)12B(T=2)
100 cts/bin ≈12 days + detector tuning → 40 shifts

7. Motivation
13Be
Method
Feasibility
Feasibility
Production target : ideally fast release – but less reliable
REXTRAP: normal mode
EBIS: Slow extraction preferred (compatibly with transmission)
12C contamination double stripper

8. Pictures

9. Cross sections
12Be(p,n)12B(T=2)
12Be(p,p)12Be

10. Example
G. V. Rogachev et al., Phys. Rev. C 67 (2003)

11. 11Be+p