1. 33Mg: determination of a negative parity intruder ground state via nuclear moments
Leuven - Mainz - ISOLDE collaboration at CERN
D. T. Yordanov1, M. Kowalska2,3, K. Blaum2, M. De. Rydt1, K. Flanagan1,
P. Lievens4, R. Neugart2, Wilfried Nörtershäuser2, H. H. Stroke5
and G. Neyens1
1 Instituut voor Kern- en Stralingsfysica, K.U.Leuven, Leuven, Belgium
2 Insititut für Physik, Universität Mainz, Mainz, Germany
3 CERN, Physics Department – IS, Geneva, Switzerland
4 Laboratorium voor Vaste-Stoffysica en Magnetisme, K.U.Leuven, Leuven, Belgium
5 Department of Physics, New York University
ISOLDE Workshop 2007

2. Table of Isotopes in the vicinity of The Island of Inversion
Measured Intruder
This Work
Normal or
not measured 4 4 4 4 1 2 1 2 1 2 1 1 1 1 3 3
1. Laser spectroscopy + NMR; Inelastic scattering;
2. Coulomb excitation; NMR;
ISOLDE Workshop 2007

3. Former experimental studies of 33Mg
b decay: 33Na, (3/2+) → 33Mg, (3/2+)
S. Nummela et al., Phys. Rev. C 64, (2001)
33Mg
33Na (3/2+)
b -
Intermediate energy Coulomb excitation:
484keV: (5/2+) → (7/2+), bC = 0.52(12)
B. V. Pritychenko et al., Phys. Rev. C 65, (2002)
Proton inelastic scattering:
484keV, 546keV – parities relative to the ground state, bM = 0.47(8)
Z. Elekes et al., Phys. Rev. C 73, (2006)
ISOLDE Workshop 2007

4. Experimental results g = -0.4971(4) I = 3/2
NMR 33Mg, MgO
|A| (I+1/2)
NMR
HFS 33Mg
A/g ≈ const
Experimental results
g = (4)
I = 3/2
preliminary
|A| (I+1/2)
≈ A (I+1)/2<0
≈ -AI/2>0
ISOLDE Workshop 2007

5. n pf sd 8 20
1d5/2
2s1/2
1d3/2
1f7/2
2p3/2
33Mg (Z=12, N=21)
1p1h
WBMB [1]
SD – PF [2]
n w Ip g
Q(mb)
3/2-
-1.47
-83
-1.35
-91 1
3/2+
0.75
135
0.78
140 2
-0.45
147
-0.47
157
I=3/2
g = (4)
QS(bC) = 151(38) mb
experiment
theory
[1] E. K. Warburton, J. A. Becker and B. A. Brown, Phys. Rev. C 41, (1990)
[2] S. Nummela et al., Phys. Rev. C 63, (2001)
ISOLDE Workshop 2007

6. n pf sd 8 20
1d5/2
2s1/2
1d3/2
1f7/2
2p3/2
33Mg (Z=12, N=21)
2p2h
WBMB [1]
SD – PF [2]
n w Ip g
Q(mb)
3/2-
-1.47
-83
-1.35
-91 1
3/2+
0.75
135
0.78
140 2
-0.45
147
-0.47
157
I=3/2
g = (4)
QS(bC) = 151(38) mb
experiment
theory
[1] E. K. Warburton, J. A. Becker and B. A. Brown, Phys. Rev. C 41, (1990)
[2] S. Nummela et al., Phys. Rev. C 63, (2001)
ISOLDE Workshop 2007

7. n pf sd 8 20
1d5/2
2s1/2
1d3/2
1f7/2
2p3/2
33Mg (Z=12, N=21)
2p2h
WBMB [1]
SD – PF [2]
n w Ip g
Q(mb)
3/2-
-1.47
-83
-1.35
-91 1
3/2+
0.75
135
0.78
140 2
-0.45
147
-0.47
157
I=3/2
g = (4)
QS(bC) = 151(38) mb
experiment
theory
[1] E. K. Warburton, J. A. Becker and B. A. Brown, Phys. Rev. C 41, (1990)
[2] S. Nummela et al., Phys. Rev. C 63, (2001)
ISOLDE Workshop 2007

8. 33Mg 2/2 = 137.7 keV a (b = 0.4) = -0.615 2/2 = 96.8 keV
PARTICLE PLUS ROTOR
Kp = 1/2+
1/2[200]
2/2 = keV
a (b = 0.4) =
-1.7 ≤ m / mN ≤ -0.17
m (31Mg) = (15) mN
Kp = 3/2-
3/2[321]
2/2 = 96.8 keV
-0.93 ≤ m / mN ≤ -0.27
m (33Mg) = (5) mN
ISOLDE Workshop 2007

9. Conclusions Outlook 33Mg (Ip = 3/2-) has a 2p2h intruder ground state
The first exited states also have intruder nature
Outlook
Investigate the neutron deficient 21Mg
Access the deformation through rms charge radii
ISOLDE Workshop 2007

11. ISOLDE - CERN 1.4 GeV protons from PSB 1.4 GeV protons from PSB
GPS Target
GPS Target
Radioactive
Laboratory
Robots
GPS
GPS
HRS Target
RILIS
Laser Ion Source
HRS
RILIS
Laser Ion Source
Control
Room
COLLAPS
REX - ISOLDE
COLLAPS
ISOLTRAP
ISOLDE Workshop 2007

12. COLLAPS @ ISOLDE b Detectors b Detectors Magnet B┴ → Magnet B┴ → N X1+
Ion Beam
X1+
Ion Beam
PM - Optical
Detection
PM - Optical
Detection
b Detectors
Electrostatic
Deflection
Electrostatic
Deflection
B װ →
Coils –
Weak Field
B װ →
Coils –
Weak Field
RF Coil
RF Coil
Post Acceleration
Lenses
UV Laser
Beam
Post Acceleration
Lenses
UV Laser
Beam
F=0
32P3/2 D2 -2 -1 1 2
32S1/2
F=1
F=2 mF S
b Detectors
I=1/2
mI = +1/2
mI = -1/2
ISOLDE Workshop 2007