1. Centre de Sciences Nucléaires et de Sciences de la Matière
Precision mass measurements of neutron-rich chromium isotopes with ISOLTRAP
Maxime Mougeot
Centre de Sciences Nucléaires et de Sciences de la Matière
CSNSM-Orsay
ISOLDE Workshop-08/12/2016

2. Mass measurements of neutron-rich chromium isotopes
Outline:
Physics motivation
Mass measurements of neutron-rich chromium isotopes
Results and Discussion
Conclusions and outlook

3. Physics Motivation

4. An onset of collectivity around N=40
neutrons 28 50
1f7/2
2p3/2
1f5/2
2p1/2
1g9/2
2d5/2 40
protons
S. M. Lenzi et al., Phys. Rev. C 82, (2010).
ENSDF database (2015).
C. Santamaria et al.,PRL 115, (2015).

5. What does the mass surface look like?
M. Wang et al., Chinese Physics C 36, 1603 (2012).
S. Naimi et al., Phys. Rev. C 86, (2012).
F. Wienholtz et al., Nature 498, 346 (2013).
X. Xing et al., Chinese Physics C 39, (2015).
L.P Gaffney et al., Eur. Phys. J. A 51, 136 (2015).

6. What does the mass surface look like?
M. Wang et al., Chinese Physics C 36, 1603 (2012).
S. Naimi et al., Phys. Rev. C 86, (2012).
F. Wienholtz et al., Nature 498, 346 (2013).
X. Xing et al., Chinese Physics C 39, (2015).
Z. Meisel et al., Phys. Rev. C 93, (2015)
L.P Gaffney et al., Eur. Phys. J. A 51, 136 (2015).

7. The IS532 experiment

8. ISOLTRAP@ISOLDE@CERN
RILIS
ISOLTRAP
1.4-GeV protons
from PSB
ISOL beams

9. Where is the Ion of Interest?

11. Multi-Reflection Time-Of-Flight
Mass Separator
F. Herfurth et al., NIM A 469, 254 (2001).
R. N. Wolf et al., Int. J. Mass Spectrom 313, 8 (2012).
G. Savard et al., Phys. Lett. A 158, 247 (1991).
M. König et al., Int. J. Mass Spectrom. 142, 95 (1995).

12. The precision Penning Trap : the ToF-ICR technique
F. Herfurth et al., NIM A 469, 254 (2001).
R. N. Wolf et al., Int. J. Mass Spectrom 313, 8 (2012).
G. Savard et al., Phys. Lett. A 158, 247 (1991).
M. König et al., Int. J. Mass Spectrom. 142, 95 (1995).

13. IS532 measurements –First measurements in 2014
52,55-58Cr measured in the Penning Trap
59Cr measured with MR-TOF MS
59Cr provided a successful test of RILIS ionization scheme
T.D Goodacre et al., Spectrochimica Acta B (in press)

14. Dedicated chromium beam time in 2016
isotope
Measured with
Half life (ms)
Yield (ions/s)
59Cr
Penning Trap/MR-TOF
1050
3E5
60Cr
490
2E4
61Cr
243
2E3
62Cr
206
3E2
63Cr
MR-TOF
129 30
T.D Goodacre et al., Spectrochimica Acta B (in press)

15. Discussion

16. The mass surface
Z. Meisel et al., Phys. Rev. C 93, (2015).

17. Preliminary The mass surface
Z. Meisel et al., Phys. Rev. C 93, (2015).

18. Comparison to theoretical models
neutrons 28 50
1f7/2
2p3/2
1f5/2
2p1/2
1g9/2
2d5/2
protons
LNPS’ valence space 40 40 *
*In Medium Similarity Renormalization Group (ab initio method)
K. Sieja, private communication(2016).
M. Honma et al, Eur. Phys. J. A 25, 499 (2005)
Stroberg et al., PRL in press.
Stroberg, Holt, Simonis, Schwenk, private communication(2016).

19. Comparison to theoretical models
neutrons 28 50
1f7/2
2p3/2
1f5/2
2p1/2
1g9/2
2d5/2
protons
GXPF1A and IMSRG valence space 40 40 *
*In Medium Similarity Renormalization Group (ab initio method)
K. Sieja, private communication(2016).
M. Honma et al, Eur. Phys. J. A 25, 499 (2005)
Stroberg et al., PRL in press.
Stroberg, Holt, Simonis, Schwenk, private communication(2016).

20. Conclusions

21. Exotic chromium isotopes up to A=63 were measured
To conclude :
Exotic chromium isotopes up to A=63 were measured
Data suggest a progressive onset of deformation
Only interactions allowing excitations across N=40 can qualitatively reproduce the trend of experimental S2n

22. Other observables would help completing the picture
Perspectives:
Other observables would help completing the picture
(e.g radii: H. Heylen et al., CERN-INTC )
The inclusion of shells beyond N=40 in the IMSRG framework is currently being developed
H. Heylen et al., Phys. Rev. C 94, (2016).

23. Acknowledgements http://isoltrap.web.cern.ch
D. Atanasov, K. Blaum, S. George, F. Herfurth, D. Lunney, V. Manea, D. Neidherr, M. Rosenbusch, L. Schweikhard, A. Welker, F. Wienholtz, R. Wolf, K. Zuber
Grants No.:
05P12HGCI1
05P12HGFNE 
ISOLDE Target
and Technical Group

24. Thank you for your attention!