Erratum: Spectroscopic Quadrupole Moments in

This corrects the article DOI: 10.1103/PhysRevLett.116.022701.

Spectroscopic Quadrupole Moments in {96,98}Sr: Evidence for Shape Coexistence in Neutron-Rich Strontium Isotopes at N=60.

Neutron-rich {96,98}Sr isotopes have been investigated by safe Coulomb excitation of radioactive beams at the REX-ISOLDE facility. Reduced transition probabilities and spectroscopic quadrupole moments have been extracted from the differential Coulomb excitation cross sections. These results allow, for the first time, the drawing of definite conclusions about the shape coexistence of highly deformed prolate and spherical configurations. In particular, a very small mixing between the coexisting states is observed, contrary to other mass regions where strong mixing is present. Experimental results have been compared to beyond-mean-field calculations using the Gogny D1S interaction in a five-dimensional collective Hamiltonian formalism, which reproduce the shape change at N=60.

Early onset of ground state deformation in neutron deficient polonium isotopes.

In-source resonant ionization laser spectroscopy of the even-A polonium isotopes (192-210,216,218)Po has been performed using the 6p(3)7s (5)S(2) to 6p(3)7p (5)P(2) (λ=843.38 nm) transition in the polonium atom (Po-I) at the CERN ISOLDE facility. The comparison of the measured isotope shifts in (200-210)Po with a previous data set allows us to test for the first time recent large-scale atomic calculations that are essential to extract the changes in the mean-square charge radius of the atomic nucleus. When going to lighter masses, a surprisingly large and early departure from sphericity is observed, which is only partly reproduced by beyond mean field calculations.

New type of asymmetric fission in proton-rich nuclei.

A very exotic process of ß-delayed fission of 180Tl is studied in detail by using resonant laser ionization with subsequent mass separation at ISOLDE (CERN). In contrast to common expectations, the fission-fragment mass distribution of the post-ß-decay daughter nucleus 180Hg (N/Z=1.25) is asymmetric. This asymmetry is more surprising since a mass-symmetric split of this extremely neutron-deficient nucleus would lead to two 90Zr fragments, with magic N=50 and semimagic Z=40. This is a new type of asymmetric fission, not caused by large shell effects related to fragment magic proton and neutron numbers, as observed in the actinide region. The newly measured branching ratio for ß-delayed fission of 180Tl is 3.6(7) × 10(-3)%, approximately 2 orders of magnitude larger than in an earlier study.

Discovery of the shape coexisting 0+ state in 32 Mg by a two neutron transfer reaction.

The "island of inversion" nucleus 32 Mg has been studied by a (t, p) two neutron transfer reaction in inverse kinematics at REX-ISOLDE. The shape coexistent excited 0+ state in 32 Mg has been identified by the characteristic angular distribution of the protons of the Δ L=0 transfer. The excitation energy of 1058 keV is much lower than predicted by any theoretical model. The low γ-ray intensity observed for the decay of this 0+ state indicates a lifetime of more than 10 ns. Deduced spectroscopic amplitudes are compared with occupation numbers from shell-model calculations.

0(gs)+ -->2(1)+ transition strengths in 106Sn and 108Sn.

The reduced transition probabilities, B(E2; 0(gs)+ -->2(1)+), have been measured in the radioactive isotopes (108,106)Sn using subbarrier Coulomb excitation at the REX-ISOLDE facility at CERN. Deexcitation gamma rays were detected by the highly segmented MINIBALL Ge-detector array. The results, B(E2;0(gs)+ -->2(1)+)=0.222(19)e2b2 for 108Sn and B(E2; 0(gs)+-->2(1)+)=0.195(39)e2b2 for 106Sn were determined relative to a stable 58Ni target. The resulting B(E2) values are approximately 30% larger than shell-model predictions and deviate from the generalized seniority model. This experimental result may point towards a weakening of the N=Z=50 shell closure.

Interplay between single-particle and collective effects in the odd-A Cu isotopes beyond N=40.

Collective properties of the low-lying levels in the odd-A 67-73Cu were investigated by Coulomb excitation with radioactive beams. The beams were produced at ISOLDE and postaccelerated by REX-ISOLDE up to 2.99 MeV/u. In 67,69Cu, low-lying 1/2(-), 5/2(-), and 7/2(-) states were populated. In 71,73Cu, besides the known transitions deexciting the single-particle-like 5/2(-) and core-coupled 7/2(-) levels, gamma rays of 454 and 135 keV, respectively, were observed for the first time. Based on a reanalysis of beta-decay work and comparison with the systematics, a spin 1/2(-) is suggested for these excited states. Three B(E2) values were determined in each of the four isotopes. The results indicate a significant change in the structure of the odd-A Cu isotopes beyond N=40 where single-particle-like and collective levels are suggested to coexist at very low excitation energies.

Coulomb excitation of neutron-rich Zn isotopes: first observation of the 2(1)+ state in 80Zn.

Neutron-rich, radioactive Zn isotopes were investigated at the Radioactive Ion Beam facility REX-ISOLDE (CERN) using low-energy Coulomb excitation. The energy of the 2(1)+ state in 78Zn could be firmly established and for the first time the 2+ --> 0(1)+ transition in 80Zn was observed at 1492(1) keV. B(E2,2(1)+ --> 0(1)+) values were extracted for (74,76,78,80)Zn and compared to large scale shell model calculations. With only two protons outside the Z=28 proton core, 80Zn is the lightest N=50 isotone for which spectroscopic information has been obtained to date. Two sets of advanced shell model calculations reproduce the observed B(E2) systematics. The results for N=50 isotones indicate a good N=50 shell closure and a strong Z=28 proton core polarization. The new results serve as benchmarks to establish theoretical models, predicting the nuclear properties of the doubly magic nucleus 78Ni.

Nuclear charge radii of neutron-deficient lead isotopes beyond N = 104 midshell investigated by in-source laser spectroscopy.

The shape of exotic even-mass (182-190)Pb isotopes was probed by measurement of optical isotope shifts providing mean square charge radii (delta(r(2))). The experiment was carried out at the isolde (cern) on-line mass separator, using in-source laser spectroscopy. Small deviations from the spherical droplet model are observed, but when compared to model calculations, those are explained by high sensitivity of delta(r(2)) to beyond mean-field correlations and small admixtures of intruder configurations in the ground state. The data support the predominantly spherical shape of the ground state of the proton-magic Z=82 lead isotopes near neutron midshell (N=104).

Coulomb excitation of 68,70Cu: first use of postaccelerated isomeric beams.

We report on the first low-energy Coulomb excitation measurements with radioactive Ipi=6- beams of odd-odd nuclei 68,70Cu. The beams were produced at ISOLDE, CERN and were post-accelerated by REX-ISOLDE to 2.83 MeV/nucleon. Gamma rays were detected with the MINIBALL spectrometer. The 6- beam was used to study the multiplet of states (3-, 4-, 5-, 6-) arising from the pi2p3/2 nu 1g9/2 configuration. The 4- state of the multiplet was populated via Coulomb excitation and the B(E2;6--->4-) value was determined in both nuclei. The results obtained illustrate the fragile stability of the Z=28 shell and N=40 subshell closures. A comparison with large-scale shell-model calculations using the 56Ni core shows the importance of the proton excitations across the Z=28 shell gap to the understanding of the nuclear structure in the neutron-rich nuclei with N approximately 40.

Measurement of the sign of the spectroscopic quadrupole moment for the 2(1)+ state in 70Se: no evidence for oblate shape.

Using a method whereby molecular and atomic ions are independently selected, an isobarically pure beam of 70Se ions was postaccelerated to an energy of 206 MeV using REX-ISOLDE. Coulomb-excitation yields for states in the beam and target nuclei were deduced by recording deexcitation gamma rays in the highly segmented MINIBALL gamma-ray spectrometer in coincidence with scattered particles in a silicon detector. At these energies, the Coulomb-excitation yield for the first 2+ state is expected to be strongly sensitive to the sign of the spectroscopic quadrupole moment through the nuclear reorientation effect. Experimental evidence is presented here for a prolate shape for the first 2+ state in 70Se, reopening the question over whether there are, as reported earlier, deformed oblate shapes near to the ground state in the light selenium isotopes.

"Safe" Coulomb excitation of 30Mg.

We report on the first radioactive beam experiment performed at the recently commissioned REX-ISOLDE facility at CERN in conjunction with the highly efficient gamma spectrometer MINIBALL. Using 30Mg ions accelerated to an energy of 2.25 MeV/u together with a thin (nat)Ni target, Coulomb excitation of the first excited 2+ states of the projectile and target nuclei well below the Coulomb barrier was observed. From the measured relative deexcitation gamma-ray yields the B(E2;0(+)gs-->2(+)1) value of 30Mg was determined to be 241(31)e2 fm4. Our result is lower than values obtained at projectile fragmentation facilities using the intermediate-energy Coulomb excitation method, and confirms the theoretical conjecture that the neutron-rich magnesium isotope 30Mg resides outside the "island of inversion."

Mie scattering of magnetic spheres.

The Mie scattering intensity of a magnetic sphere has been derived by extending the classical Mie scattering approach to a media where the dielectric constant is no more a real number but a tensor with a gyrotropic form. Using a perturbation method the propagation equations of the electromagnetic field are derived. For an incident plane wave the magnetization effect could be detectable. The Mie scattering intensity is analyzed for special incident wave configurations, in particular, for the case where the magnetic field of the incident plane wave is polarized along the magnetization direction. This magnetization effect is most important for the finger pattern of the backscattering intensity. Magnetic Mie scattering is still significant for a magnetic sphere of radius larger than 10 nm.

Monte Carlo model of the Elekta SLiplus accelerator: validation of a new MLC component module in BEAM for a 6 MV beam.

A new component module (CM), called MLCE, has been implemented in the BEAM program. The CM takes into account the particular 'tongue-and-groove' design of the Elekta multi-leaf collimator (MLC) and the air gap between the leaves. The model was validated by two series of measurements and simulations. The first benchmarking series focuses on the interleaf leakage and the intraleaf transmission. The measurement showed a total transmission through the MLC of 1.42% of the open field dose. Two Monte Carlo (MC) simulations were made, the first with the new CM MLCE (inclusive of air gap) and the second with the CM MLCQ (exclusive of air gap), which is available in the BEAM distribution. When the air gap between the leaves was determined by varying the parameters of the leaf geometry within tolerance limits on the technical drawing, the total measured transmission of 1.42% was well reproduced by the CM MLCE. In contrast, MC simulations with MLCQ showed that the transmission through the MLC calculated without the interleaf leakage is only 44% of the total transmitted radiation. The relevance of the detailed MLC modelling was demonstrated also by studying the 'adjacent' tongue-and-groove effect, where two adjacent (not opposing) leaves are complementary, opened or closed. The two complementary leaf settings were simulated both with the CM MLCE and MLCQ. A comparison with measurements was made. In regions covered by two or more leaves, the dose increased by 14% for two leaves and by 40% for more than two leaves when the interleaf leakage was included in the transmission. The tongue-and-groove effect was perfectly reproduced by the MLCE module.

[Ventricular arrhythmia in the athlete: practical management]. / Arythmie ventriculaire chez le sportif: conduite pratique.

The aim of athletic competition is to exceed ones present limits, which exposes the athlete to increased risk is helshe has a cardiac disorder. Ventricular excitability is not part of the athletic heart syndrome, and only the presence of resting ventricular extrasystoles that are monomorphic, ungrouped and disappear with exercise can be considered physiological. Significant ventricular arrhythmia can reflect a cardiac disorder that should be routinely sought in order to determine if there is a potential risk of sudden death favoured by physical effort. The confirmation of arrhythmia and seeking a cardiac disorder require a rigorous approach based on history-taking, clinical examination and initial performance of non-invasive, orienting examinations. Invasive examinations, based on the case, are often required if a disorder is suspected or if there is a question concerning the severity of the arrhythmia. Decisions concerning aptitude for competition are decided case by case, according to the disorder, with reference to the 26th Bethesda Conference. If the ventricular arrhythmia is shown to be benign and no underlying cardiac disorder exists, athletic competition may be pursued without restrictions. In case of contrary findings, physical activity will be limited and the authorized level will be precisely determined according to the context and the results of exertion tests made during treatment.

One thousand video-urodynamic studies in children with non-neurogenic bladder sphincter dysfunction.

OBJECTIVE: To ascertain the aetiology and epidemiology of non-neurogenic bladder sphincter dysfunction (NNBSD) by assessing the results of prospective video-urodynamic studies (VUD) in 1000 children. PATIENTS AND METHODS: During a 4-year study period (January 1995 to December 1998) 1000 children prospectively underwent VUD to further define their NNBSD. After a noninvasive screening assessment consisting of a history, voiding diary, clinical examination, urine analysis, ultrasonography and uroflowmetry, those children who would benefit from further VUD were selected. The selection criteria included a history of urinary tract infection (UTI), a small bladder capacity not responding to training, dysfunctional uroflow, ultrasonographic abnormalities and resistance to therapy. During the study period 3500 children were screened for incontinence problems, including monosymptomatic nocturnal enuresis; 1000 of these were selected for VUD (524 boys and 476 girls). RESULTS: The urodynamic diagnosis was of normal bladder-sphincter function in 62 (6.2%, male : female 44 : 56), urge syndrome in 582 (58%, 58 : 42), dysfunctional voiding in 316 (32%, 49 : 51) and 'lazy bladder' in 40 (4%, 20 : 80). Boys diagnosed with a 'lazy bladder' were younger than those with urge syndrome and dysfunctional voiding. Girls with dysfunctional voiding were younger than those with urge syndrome. The incidence of UTI was significantly higher in girls than in boys; boys with NNBSD had no greater risk for UTI and in girls the general risk was 34%. Only in girls with a lazy bladder was there a significantly higher incidence of UTI (53%). Reflux occurred equally in all groups, with an overall incidence of 15%. The incidence of obstipation was significantly higher in girls with a lazy bladder, and overall was 17%. CONCLUSION: These results from a large series provide a new insight into the epidemiology and pathophysiology of NNBSD. The age distribution provides evidence against a dysfunctional voiding sequence. The risk of developing UTI in NNBSD is greater only in girls. In children with a lazy bladder the risk is also significantly higher, indicating that residual urine is a greater risk factor than detrusor instability. Urge syndrome and dysfunctional voiding in girls carry the same risk for developing UTI, indicating that bladder instability is a higher risk factor for UTI than detrusor sphincter discoordination. All dysfunctions carry an equal risk for developing secondary reflux. Children with NNBSD have different primary diseases but all have a common risk of incontinence, UTIs, reflux and obstipation.

[A new case of pericardial thymic cyst]. / Un nouveau cas de kyste thymique paracardiaque.

The thymic cysts are benign tumours of the thymo-pharyngeal canal, usually located in the cervico-mediastinal region. The authors report the case of a large thymic cyst with an ectopic right paracardiac location compressing the right heart chambers. It was a chance finding on chest X-ray of an asymptomatic 21 year old man. Though suggestive of a pericardial cyst in view of its position, curative surgical ablation allowed confirmation of the diagnosis at anatomo-pathological examination.

[Increase of troponin I during acute pericarditis. 69 cases at an emergency service]. / Elévation de troponine i lors d'une péricardite aiguë. 69 observations en service d'urgence.

OBJECTIVE: The purpose of this study was to determine the incidence and significance of troponin i (tni) elevation in acute pericarditis. PATIENTS AND METHODS: We retrospectively included 69 patients with acute idiopathic pericarditis. We analyzed ECG recordings, echocardiography findings and tni level. Thirty-four patients (49%) had detectable tni (> 0.5 ng/ml), 15 (22%) had a significantly elevated level (> 1.5 ng/ml). There was a significant correlation between elevated tni level and ST elevation. All patients were well at one year. CONCLUSIONS: A rise in tni is frequently observed during acute idiopathic pericarditis. According to the correlation with ST segment elevation, a rise in tni is apparently indicative of superficial myocardial damage. The prognostic value remains unknown.

[Paraganglioma associated with renal artery stenosis: unusual cause of secondary arterial hypertension. A case report and review of the literature]. / Paragangliome associé à une sténose de l'artère rénale: une cause rare d'hypertension artérielle secondaire. A propos d'un cas et revue de la littérature.

Secreting paraganglioma is a rare cause of secondary HT and corresponds to an extra-adrenal phaeochromocytoma. This case reports the consecutive coexistence, with a free interval of 10 years, of dysplastic renovascular HT and abdominal paranganglioma in the organ of Zuckerkandl. This is a rare association which requires investigation of a common genetic predisposition (neural crest disease) and emphasizes the importance of long-term surveillance of these patients.