1. Recent Highlights and Future Plans at VAMOS
Structure of exotic neutron rich nuclei
New/Unique program
Inverse kinematics with heavy beams around the Coulomb barrier
High resolution, efficient magnetic and gamma spectrometers
Improvement of sensitivity
Path towards SPIRAL2

2. Physics Goals
Exploring nuclear structure far from stability using Deep Inelastic Reactions
Evolution of shell structure
Shapes and collective excitations
Highlights
Absence of a predicted shell closure at N=34
Presence of triaxial shapes near shell closures
Tomorrow mapping a structure of fission fragments
Towards 132Sn, 78Ni
Reflection assymetric shapes

3. VAMOS Unique Spectrometer
Essential for nuclear structure and reaction studies
Identification of reaction products
Large acceptance
Coupling with different arrays (EXOGAM, MUST2 …)
Beam
Target

4. VAMOS Schematic View Focal Plane detection DIPOLE QUADRUPOLES EXOGAM
BEAM
Focal Plane detection
DIPOLE
Velocity Filter

5. Variable Mode Operation
QQ – Focusing Mode
QQD – Spectrometer
Variable Dispersion
Recoil Separator
QQF(D)
QQD (Gas filled)*
Detectors
beam
Ref :NIM B 204(2003)146

6. Focal Plane Setup Software Spectrometer
Initial coordinates deduced from final coordinates

7. Focal Plane Setup
Si Wall
Drift Chamber
beam IC
SeD

8. Identification spectra
Target-like
48Ar N/Z=1.67
highest reached in this kind of reaction
238U
5.5 MeV/u
Beam
Target : 48Ca

9. Neutron rich isotopes of Calcium
Doppler corrected using V from VAMOS
238U (5.5 MeV/u) + 48Ca

10. No new shell gap at N=34 in Calcium
M. Rejmund et al. PRC 76, (R) (2007)

11. Neutron rich isotopes of Argon
Doppler corrected using V from VAMOS
238U (5.5 MeV/u) + 48Ca

12. Neutron rich Argon and collectivity
S. Bhattacharyya et al. PRL 101, (2008)

13. Acceptance of VAMOS
Bρ [Tm]
Ω [mSr]

14. Acceptance is determined by a detector size !
~45 cm

15. Ongoing improvement By doubling of size of the focal plane detection
S. Pullanhiotan et al, NIM A 593 (2008) 343

19. VAMOS++

20. Wide ranging opportunities with VAMOS
Improvements of efficiency and resolving power will take us towards presently unachievable goals and benefit nuclear physics community
Coupling EXOGAM, AGATA, MUST2, TIARA, INDRA…
Physics of “exotic phenomena” with reactions ranging from transfer to multifragmentation