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Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for {sup 27}F, {sup 27}Ne, {sup 27}Na, {sup 27}Mg, {sup 27}Al, {sup 27}Si, {sup 27}P, and {sup 27}S. This evaluation for A=27 supersedes the earlier evaluation by P.M. Endt (1998En04 and 1990En08).
The experimental data are evaluated for known nuclides of mass number A=44 (Si,P,S,Cl,Ar,K,Ca,Sc,Ti,V, Cr,Mn). Detailed evaluated level properties and related information are presented, including adopted values of level and {gamma}-ray energies, decay data (energies, intensities and placement of radiations), and other spectroscopic data. This work supersedes earlier full evaluations of A=44 published by 1999Ca45 and 1990En08 (also 1998En04 update). No excited states are known in {sup 44}Si, {sup 44}P, {sup 44}Cr, {sup 44}Mn. Only one excited state is known in 44V and its Isobaric Analog State (IAS) has been observed but with the level energy not known. Information for {sup 44}S, {sup 44}Cl and {sup 44}Ar is limited and their radioactive decay schemes seem incomplete in view of large Q values and known excitations much below than allowed by Q values. The {sup 44}Ca, {sup 44}Sc and {sup 44}Ti nuclides remain as the most extensively studied from many different reactions and decays.
An exclusive study of {sup 17}F breakup reactions has been performed at the FRIBs facility of the Laboratori Nazionali del Sud in Catania (Italy). The experiment has been performed with the aim of testing the accuracy of the Coulomb-breakup indirect technique used to infer radiative-capture cross sections at low energies. This technique has been used in the {sup 7}Be(p,{gamma}){sup 8}B case, but has never been tested. By measuring the breakup of {sup 17}F into {sup 16}O+p, and comparing the inferred cross section for {sup 16}O(p,{gamma}){sup 17}F to direct precise measurements, the influence of E2 transitions and higher-order effects, that are predicted to be significant in Coulomb-breakup reactions, can be evaluated. The first results and preliminary model comparison are reported.
The rare-RI (radioactive isotope) ring at the RIKEN RI Beam Factory is described. The main purpose of the rare-RI ring is to measure the mass of short-lived rare RI. In the rare-RI ring, the mass is determined by measuring the revolution time of each nucleus based on isochronous mass spectrometry. The rare-RI ring consists of six magnetic sectors, and each sector consists of four dipole magnets. To precisely optimize the isochronous conditions of the circulating particles for large acceptance, we install 10 trim coils to half of the dipole magnets. Individual injection system enables efficient injection of the produced rare RI into the ring one by one. With facilitating efficient extraction of the circulating particles, time-of-flight measurements can be performed to the each rare RI. Construction of the rare-RI ring was begun in the middle of the fiscal year 2012, and the ring is expected to be fully functional by 2015, when we can start the mass measurements for unknown masses.
Laser spectroscopy was performed on the {sup 72,74,76,78}Ga isotopes at On-Line Isotope Mass Separator (ISOLDE) facility, CERN. Ground-state nuclear spins and moments were extracted from the measured hyperfine spectra. The results are compared to shell-model calculations, which provide a detailed probe of the nuclear wave function. The spin is established from the shape of the hyperfine structure and the parity inferred from a comparison of shell-model calculations with the measured nuclear moments. The ground states of {sup 76,78}Ga are both assigned a spin and parity of I{sup {pi}=}2{sup -}, while {sup 74}Ga is tentatively assigned as I{sup {pi}=}3{sup -}. For {sup 72}Ga, the results are consistent with the previous I=3 assignment.
We report on the changes in mean square charge radii of unstable neon nuclei relative to the stable {sup 20}Ne, based on the measurement of optical isotope shifts. The studies were carried out using collinear laser spectroscopy on a fast beam of neutral neon atoms. High sensitivity on short-lived isotopes was achieved thanks to nonoptical detection based on optical pumping and state-selective collisional ionization, which was complemented by an accurate determination of the beam kinetic energy. The new results provide information on the structural changes in the sequence of neon isotopes all across the neutron sd shell, ranging from the proton drip line nucleus and halo candidate {sup 17}Ne up to the neutron-rich {sup 28}Ne in the vicinity of the ''island of inversion.'' Within this range the charge radius is smallest for {sup 24}Ne with N=14 corresponding to the closure of the neutron d{sub 5/2} shell, while it increases toward both neutron shell closures, N=8 and N=20. The general trend of the charge radii correlates well with the deformation effects which are known to be large for several neon isotopes. In the neutron-deficient isotopes, structural changes arise from the onset of proton-halo formation for {sup 17}Ne, shell closure in {sup 18}Ne, and clustering effects in {sup 20,21}Ne. On the neutron-rich side the transition to the island of inversion plays an important role, with the radii in the upper part of the sd shell confirming the weakening of the N=20 magic number. The results add new information to the radii systematics of light nuclei where data are scarce because of the small contribution of nuclear-size effects to the isotope shifts which are dominated by the finite-mass effect.
We report a measurement of the neutrino-electron elastic scattering rate from {sup 8}B solar neutrinos based on a 123 kton-day exposure of KamLAND. The background-subtracted electron recoil rate, above a 5.5-MeV analysis threshold is 1.49 {+-} 0.14(stat) {+-} 0.17(syst) events per kton-day. Interpreted as due to a pure electron flavor flux with a {sup 8}B neutrino spectrum, this corresponds to a spectrum integrated flux of 2.77 {+-} 0.26(stat) {+-} 0.32(syst) x10{sup 6} cm{sup -2}s{sup -1}. The analysis threshold is driven by {sup 208}Tl present in the liquid scintillator, and the main source of systematic uncertainty is due to background from cosmogenic {sup 11}Be. The measured rate is consistent with existing measurements and with standard solar model predictions which include matter-enhanced neutrino oscillation.
Assuming that the ratio between asymptotic normalization coefficients of mirror states is model independent, charge symmetry can be used to indirectly extract astrophysically relevant proton capture reactions on proton-rich nuclei based on information on stable isotopes. The assumption has been tested for light nuclei within the microscopic cluster model. In this work we explore the Hamiltonian independence of the ratio between asymptotic normalization coefficients of mirror states when deformation and core excitation is introduced in the system. For this purpose we consider a phenomenological rotor+N model where the valence nucleon is subject to a deformed mean field and the core is allowed to excite. We apply the model to {sup 8}Li/{sup 8}B, {sup 13}C/{sup 13}N, {sup 17}O/{sup 17}F, {sup 23}Ne/{sup 23}Al, and {sup 27}Mg/{sup 27}P. Our results show that, for most studied cases, the ratio between asymptotic normalization coefficients of mirror states is independent of the strength and multipolarity of the couplings induced. The exception is for cases in which there is an s-wave coupled to the ground state of the core, the proton system is loosely bound, and the states have large admixture with other configurations. We discuss the implications of our results for novae.
The stellar reaction {sup 26}Si(p, {gamma}){sup 27}P was studied in the Coulomb dissociation of {sup 27}P. Two known resonance levels in {sup 27}P were excited and a candidate for the third excited state was found in the {sup 26}Si p relative energy spectrum. The E2 resonance strengths {omega}{gamma} were obtained to be (6.5{+-}1.3)x10{sup -11}, (6.0{+-}1.1)x10{sup -10}, and (1.10{+-}0.27)x10{sup -10} MeV. The total (E2+M1) {omega}{gamma} value for the first excited state was evaluated to be 1.9{sub -1.1}{sup +1.9}x10{sup -9} MeV with the help of the shell model. The error was estimated from the deviation of theoretical predictions with the same shell model from experimental strengths obtained in the present study for {sup 27}P and earlier ones for the mirror nucleus {sup 27}Mg. The astrophysical reaction rate for the {sup 26}Si(p, {gamma}){sup 27}P reaction was also calculated and compared with previous estimations.
The evaluated spectroscopic data are presented for known nuclides of mass 249 (Cm, Bk, Cf, Es, Fm, Md, No). {sup 249}No has not been identified as yet. Significant amounts of new data have been added since the last evaluation of A=249 nuclides. This work supersedes earlier full evaluations of A=249 published by 1999Ar21.
Modern models of s-process nucleosynthesis in stars require stellar reaction rates of high precision. Most neutron-capture cross-sections in the s-process have been measured, and for an increasing number of reactions the required precision is achieved. This does not necessarily mean, however, that the stellar rates are constrained equally well, because only the capture of the ground state of a target is measured in the laboratory. Captures of excited states can contribute considerably to stellar rates that are already at typical s-process temperatures. We show that the ground-state contribution X to a stellar rate is the relevant measure to identify reactions that are or could be well constrained by experiments and apply it to (n,{gamma}) reactions in the s-process. We further show that the maximum possible reduction in uncertainty of a rate via determination of the ground-state cross-section is given directly by X. An error analysis of X is presented, and it is found that X is a robust measure with mostly small uncertainties. Several specific examples (neutron capture of {sup 79}Se, {sup 95}Zr, {sup 121}Sn, {sup 187}Os, and {sup 193}Pt) are discussed in detail. The ground-state contributions for a set of 412 neutron-capture reactions around the s-process path are presented in a table. This allows identification of reactions that may be better constrained by experiments and that cannot be constrained solely by measuring ground-state cross-sections (and thus require supplementary studies). General trends and implications are discussed.
Purpose: To determine the dose dependence and kinetics of pneumopathy after systemic administration of rhenium-188 ({sup 188}Re)-labeled microspheres in a rat model. Methods and Materials: {sup 188}Re-microspheres were injected intravenously into adult Wistar rats (n = 54, age, 8 {+-} 2 months). The rats were divided into 6 groups according to the intended absorbed dose in the lung (maximum 60 Gy). Gamma camera scans were used to estimate the individual whole lung doses. One control group (n = 5) received nonlabeled microspheres. The breathing rate was measured before and weekly after the treatment using whole body plethysmography until 24 weeks. An increase in the breathing rate by 20% compared with the individual pretreatment control value was defined as the quantal endpoint for dose-effect analyses. Results: A biphasic increase in the breathing rate was observed. The first impairment of lung function occurred in Weeks 3-6. For late changes, the interval to onset was clearly dose dependent and was 17 weeks (10-30 Gy) and 10 weeks (50-60 Gy), respectively. The incidence of the response was highly dependent on the estimated lung dose. The median effective dose for an early and late response was virtually identical (19.9 {+-} 0.6 Gy and 20.4 {+-} 3.1 Gy, respectively). A significant correlation was found between the occurrence of an early and a late effect in the same rat, suggesting a strong consequential component. Conclusions: The effects of radiolabeled microspheres can be studied longitudinally in a rat model, using changes in the breathing rate as the functional, clinically relevant response. The isoeffective doses from the present study using radionuclide administration and those from published investigations of homogeneous external beam radiotherapy are almost similar.
The X(5) symmetry describes nuclei at the critical point of the shape phase transition from axially deformed rotor nuclei to spherical vibrators. {sup 150}Nd, {sup 152}Sm, and {sup 154}Gd were the first nuclei where the predicted characteristics of the X(5) symmetry were observed. Later it was shown that also {sup 176,178,180}Os can be successfully described with the X(5) symmetry.In the close vicinity of shape phase transitions one expects strongly changing nuclear shapes. In the X(5) region around A = 150 this was observed for nuclei with different neutron numbers, whereas in the X(5) region around A = 180 this is to be expected for different proton numbers. The aim of the work presented here is the confirmation of a rapid shape change for nuclei close to {sup 178}Os. Besides the knowledge on the level scheme of the nuclei of interest, especially absolute E2 transition strengths are crucial for the interpretation of nuclear structure. Prolate deformation is expected for {sup 176}W. Thus we performed a recoil distance Doppler shift (RDDS) measurement on {sup 176}W to measure E2 transition strengths from level lifetimes. The experiment was performed at the Cologne FN TANDEM accelerator with the Cologne coincidence plunger with the reaction {sup 169}Dy({sup 16}O,4n){sup 176}W and a beam energy of 80 MeV. We will present our experimental results and relate them to data on the neighboring nuclei {sup 178}Os and {sup 182}Pt. The results will be discussed in the framework of nuclear shape transitions in this mass region and compared to calculations with both the Interacting Boson Model (IBM) and the GCM.
Purpose: Skin cancer is the most common malignancy in white populations. We evaluated the local cure rate and cosmetic outcome of patients with basal cell carcinoma (BCC) or squamous cell carcinoma (SCC) of the face treated with low-dose rate brachytherapy. Methods and Materials: Between February 1990 and May 2000, 147 facial carcinomas in 132 patients were treated by {sup 192}Ir wire implantation. Side effects of brachytherapy were noted. Follow-up was 2 years or more. Locoregional recurrence-free survival (LRFS) and overall survival were recorded. Group A included patients treated by primary brachytherapy, and Group B included those treated after recurrence. Results: A total of 121 carcinomas were BCCs (82.3%) and 26 were SCCs (17.7%); the median tumor size was 10 mm. Of the tumors, 86 (58.5%) were in men and 61 (41.5%) were in women; the median age was 71 years. Group A comprised 116 lesions (78.9%), and Group B, 31 (21.1%). There were 17 relapses (11.6%) after a median follow-up of 72 months: 12 local, 4 nodal, and 1 local and nodal. Locoregional-free survival was 96.6% at 2 years and 87.3% at 5 years. Five-year LRFS was 82.6% in men and 93.3% in women (p = 0.027). After adjustment for gender, LRFS was better after primary treatment than after recurrence (hasard ratio HR, 2.91; 95% confidence interval, 1.06-8.03; p = 0.039). Five-year LRFS was 90.4% for BCC and 70.8% for SCC (p = 0.03). There were no Grade 3 complications. Conclusions: Low-dose rate brachytherapy offers good local control and cosmetic outcome in patients with periorificial skin carcinomas, with no Grade 3 complications. Brchytherapy is more efficient when used as primary treatment.
The stable Cd isotopes have long been used as paradigms for spherical vibrational motion. Extensive investigations with in-beam {gamma} spectroscopy have resulted in very-well-established level schemes, including many lifetimes or lifetime limits. A programme has been initiated to complement these studies with very-high-statistics {beta} decay using the 8{pi} spectrometer at the TRIUMF radioactive beam facility. The decays of {sup 112}In and {sup 112}Ag have been studied with an emphasis on the observation of, or the placement of stringent limits on, low-energy branches between potential multi-phonon levels. A lack of suitable 0{sup +} or 2{sup +} three-phonon candidates has been revealed. Further, the sum of the B(E2) strength from spin 0{sup +} and 2{sup +} states up to 3 MeV in excitation energy to the assigned two-phonon levels falls far short of the harmonic-vibrational expectations. This lack of strength points to the failing of collective models based on vibrational phonon structures.
Purpose: This study was designed to investigate the clinical outcome of patients with irresectable, intrahepatic cholangiocarcinoma (IHC) treated with computed tomography (CT)-guided HDR-brachytherapy (CT-HDRBT) for local tumor ablation.MethodFifteen consecutive patients with histologically proven cholangiocarcinoma were selected for this retrospective study. Patients were treated by high-dose-rate internal brachytherapy (HDRBT) using an Iridium-192 source in afterloading technique through CT-guided percutaneous placed catheters. A total of 27 brachytherapy treatments were performed in these patients between 2006 and 2009. Median tumor enclosing target dose was 20 Gy, and mean target volume of the radiated tumors was 131 ({+-} 90) ml (range, 10-257 ml). Follow-up consisted of clinical visits and magnetic resonance imaging of the liver every third month. Statistical evaluation included survival analysis using the Kaplan-Meier method. Results: After a median follow-up of 18 (range, 1-27) months after local ablation, 6 of the 15 patients are still alive; 4 of them did not get further chemotherapy and are regarded as disease-free. The reached median local tumor control was 10 months; median local tumor control, including repetitive local ablation, was 11 months. Median survival after local ablation was 14 months and after primary diagnosis 21 months. Conclusion: In view of current clinical data on the clinical outcome of cholangiocarcinoma, locally ablative treatment with CT-HDRBT represents a promising and safe technique for patients who are not eligible for tumor resection.
The aim of the present study was to investigate the potential of the naturally occurring salt for the dosimetry purposes, using TL. The fine powder samples (20 mg) were irradiated by {gamma}- rays from 500 mGy to 2500 mGy by using Theratron-780C Cobalt-60 source, however, this paper discusses about 500 mGy only. The TL glow curve peak parameters were studied by using Chen's peak shape equation. TL glow curves were compared with fitted curves using glow curve deconvolution (GCD) method by using Kitis expression. The kinetic parameter values (E, b and s) so calculated, are in good agreement with those available in literature. The calculated energy values were also verified by using various heating rate (VHR) method. {chi}{sup 2} test and figure of merit (FOM) calculation was done to accept the goodness of fit between the curves. Fading studies of the sample showed a good fitting between the curves. The analysis suggests that natural salt should be considered for dosimetry purposes.
High-spin states in {sup 139}Nd were investigated using the reaction {sup 96}Zr({sup 48}Ca,5n) at a beam energy of 195 MeV and {gamma}-ray coincidences were acquired with the Euroball spectrometer. Apart from several dipole bands at medium excitation energy, three quadrupole bands have been observed at high spin. Linking transitions connecting two of the high-spin bands to low-energy states have been observed. Calculations based on the cranked-Nilsson-Strutinsky formalism have been used to assign configurations for the high-spin quadrupole bands.