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The 12C+12C fusion reaction was studied in the range of E c.m.=8.9 to 21 MeV using the active-target Time Projection Chamber. With full information on all tracks of the reaction products, cross sections of the 12C(12C,8Be)16Og.s. channel and the 12C(12C,3α)12C channel could be measured down to the level of a few milibarns. The 12C(12C,8Be)16Og.s. reaction channel was determined to be 10 mb at E c.m.=11.1 MeV, supporting the direct α transfer reaction mechanism. The 12C(12C,3α)12C reaction channel was studied for the first time using an exclusive measurement. Our result does not confirm the anomaly behavior reported in the previous inclusive measurement by Kolata et al. [Phys. Rev. C 21, 579 (1980)]. Our comparisons with statistical model calculations suggest that the 3α channel is dominated by the fusion evaporation process at E c.m. > 19 MeV. The additional contribution of the 3α channel increases the fusion reaction cross section by 10% at energies above 20 MeV. We also find that an additional reaction mechanism is needed to explain the measured cross section at E c.m. < 15 MeV at which point the statistical model prediction vanishes.

Reaccelerated radioactive beams near the Coulomb barrier, which are starting to be available from the ReA3 accelerator at NSCL and in next future at FRIB, will open up new opportunities for the study of nuclear structure near the drip lines. Efficient measurement techniques must be developed to compensate for the limited intensity of the most exotic beams. The Active-Target Time Projection Chamber (AT-TPC) constructed at MSU solves this problem by providing the increased luminosity of a thick target while maintaining a good energy resolution by tracking the reaction vertex over an essentially 4 π solid angle. The AT-TPC and similar detectors allow us to take full advantage of the radioactive ion beams at present and future nuclear physics facilities to explore the frontier of rare isotopes.

The extinct p-process nuclide 146Sm (t1/2 = 103 ± 5 Myr) is known to have been present in the Early-Solar System and has been proposed as an astrophysical chronometer. 146Sm is also intensely used to date meteorite and planetary differentiation processes, enhancing the importance of an accurate knowledge of the 146Sm half-life. We are engaged in a new determination of the 146Sm half-life in which the 146Sm/147Sm atom ratio is determined by accelerator mass spectrometry at the ATLAS facility of Argonne National Laboratory. In order to reduce systematic errors in the AMS determination of the 146Sm/147Sm ratios (in the range of 10-7-10-9), 146Sm and 147Sm ions were alternately counted in the same detector in the focal plane of a gas-filled magnet, respectively in continuous-wave and attenuated mode. Quantitative attenuation is obtained with the 12 MHz pulsed and ns-bunched ATLAS beam by chopping beam pulses with an RF sweeper in a ratio (digitally determined) down to 1:106. The experiments and preliminary results are discussed. © 2012 Elsevier B.V. All rights reserved., SCOPUS: cp.j, info:eu-repo/semantics/published

The Prototype AT-TPC, a detector based on time projection chamber (TPC) technology was built at the National Superconducting Cyclotron Laboratory, Michigan State University. The chamber gas, called the active target, of the Prototype AT-TPC is utilized simultaneously as a reaction target and a tracking medium of charged particles for measuring low-energy nuclear reactions. In pursuit of luminosity, efficiency and resolution for reaction studies at a new generation of radioactive isotope facilities, the Prototype AT-TPC provides one of the largest active volumes in the world measuring 25 cm in diameter and 50 cm long along the beam axis, millimeter-precision tracking capability, and a high electric field of 1 kV/cm/atm for fast electron drift, which limits the detector dead time. Commissioning of the detector using standard alpha sources and radioactive 6 He beams has demonstrated the detector's long-term stability as well as its performance, which allowed good reconstruction of reaction kinematics.

A particle- γ coincidence technique has been used to measure the fusion cross-section in the system 12C+12C at low beam energies. Based on these results, it should be possible to measure this important fusion cross-section down to the 10 pb level within a week-long run.

Proton radioactivity from 117 La was re-investigated with much improved statistics and precision. Only the ground-state proton decay ( E p = 813 ( 3 ) keV , T 1 / 2 = 20.1 ( 25 ) ms ) was observed, no evidence for a previously reported isomeric proton decay was found. Prompt γ rays in 117 La were identified using the Recoil–Decay Tagging method. Overall the data indicate that the proton-emitting state is associated with a K π = 3 / 2 + configuration, in agreement with all the published proton-decay calculations and predictions for the ground-state configuration of 117 La calculated in the framework of either adiabatic or non-adiabatic particle models. However, this is not in agreement with the most recent state-of-the-art quasi-particle non-adiabatic model calculations which predict a K π = 7 / 2 − configuration.

The $^{17}\text{O}(p,\ensuremath{\alpha})^{14}\text{N}$ and $^{17}\text{O}(p,\ensuremath{\gamma})^{18}\text{F}$ reactions are of paramount importance for the nucleosynthesis in a number of stellar sites, including red giants (RGs), asymptotic giant branch (AGB) stars, massive stars, and classical novae. In particular, they govern the destruction of $^{17}\text{O}$ and the formation of the short-lived radioisotope $^{18}\text{F}$, which is of special interest for $\ensuremath{\gamma}$-ray astronomy. At temperatures typical of the above-mentioned astrophysical scenario, $T=0.01$--0.1 GK for RG, AGB, and massive stars and $T=0.1$--0.4 GK for a classical nova explosion, the $^{17}\text{O}(p,\ensuremath{\alpha})^{14}\text{N}$ reaction cross section is dominated by two resonances: one at about ${E}_{R}^{cm}=65$ keV above the $^{18}\text{F}$ proton threshold energy, corresponding to the ${E}_{X}=5.673$ MeV level in $^{18}\text{F}$, and another one at ${E}_{R}^{cm}=183$ keV $({E}_{X}=5.786$ MeV). We report on the indirect study of the $^{17}\text{O}(p,\ensuremath{\alpha})^{14}\text{N}$ reaction via the Trojan Horse method by applying the approach recently developed for extracting the strength of narrow resonance at ultralow energies. The mean value of the strengths obtained in the two measurements was calculated and compared with the direct data available in literature. This value was used as input parameter for reaction-rate determination and its comparison with the result of the direct measurement is also discussed in the light of the electron screening effect.

The proton decay of $^{53}\mathrm{Co}^{m}$($3174.1\phantom{\rule{4.pt}{0ex}}\text{keV},19/{2}^{\ensuremath{-}}$) was investigated via the fragmentation of a $^{58}\mathrm{Ni}$ primary beam. The proton-decay energy was determined with an improved precision to be $1558\phantom{\rule{0.16em}{0ex}}(8)\phantom{\rule{4.pt}{0ex}}\text{keV}$. With this new result and the mass of $^{53}\mathrm{Co}^{m}$, the $^{52}\mathrm{Fe}$ mass excess was derived to be $\ensuremath{-}48\phantom{\rule{0.16em}{0ex}}330\phantom{\rule{0.16em}{0ex}}(8)\phantom{\rule{4.pt}{0ex}}\text{keV}$, which is in good agreement with the AME12 value. A new recommended value of $\ensuremath{-}48\phantom{\rule{0.16em}{0ex}}331.6\phantom{\rule{0.16em}{0ex}}(49)\phantom{\rule{4.pt}{0ex}}\text{keV}$ is given.

The excitation function for the fusion–evaporation reaction Si 28 + Ni 64 has been measured down to a cross section of 25 nb. This is the first observation of fusion hindrance at extreme sub-barrier energies for a system with a small, negative Q-value ( − 1.78 MeV ). This result is further proof that heavy-ion fusion hindrance, reported earlier only for systems with large, negative Q-values, is a general phenomenon. The measured behavior can be reproduced by coupled-channels calculations with a modified ion–ion potential incorporating the effects of nuclear incompressibility.

A new focal-plane detector system has been designed and constructed for measuring very small heavy-ion induced fusion-evaporation cross sections with the Fragment Mass Analyzer (FMA) at Argonne National Laboratory. The system has been tested and successfully used in a fusion-evaporation excitation function measurement for 64 Ni + 100 Mo down to the 5 nb level. The design and performance of the detector system are described in detail with some examples from the latest data. Besides excellent tracking capabilities for each event measured in the detector, suppression of scattered beam background of the order of 4 × 10 - 17 has been demonstrated.

The (8)B(alpha,p)(11)C reaction is part of the network that can bypass the triple a process leading to the production of (12)C. We have measured the astrophysical reaction rate for this reaction by studying the inverse (11)C(p,alpha)(8)B process. The radioactive (11)C beam was produced via the p((11)B,(11)C)n reaction using the in-flight facility at the ATLAS accelerator. The astrophysical reaction rate obtained from the excitation function measured in the energy range E(x)=8.8-10 MeV was found to be a factor of 10-50 higher than previous estimates.

We have measured the fusion cross sections of the 12C(13C, p)24Na reaction through off-line measurement of the beta-decay of 24Na using the beta-gamma coincidence method. Our new measurements in the energy range of Ec.m. = 2.6-3.0 MeV do not show an obvious S-factor maximum but a plateau. Comparison between this work and various models is presented., Comment: 3 pages, 3 figures, Talk at the "10th International Conference on Nucleus-Nucleus Collisions", Beijing, 16-21 August 2009

A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the (α, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for (α, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only (α, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. × 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the (α, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the (α, p) reaction to reach the anode segment below the reaction.

Cross section measurements of the reactions ${}^{90,92}$Zr($p$,$\ensuremath{\gamma}$)${}^{91,93}$Nb were performed using the National Superconducting Cyclotron Laboratory Summing NaI(Tl) detector at the University of Notre Dame. These reactions are part of the nuclear reaction flow for the synthesis of the light $p$ nuclei. For the ${}^{90}$Zr($p$,$\ensuremath{\gamma}$)${}^{91}$Nb reaction the new measurement resolves the disagreement between previous results. For the ${}^{92}$Zr($p$,$\ensuremath{\gamma}$)${}^{93}$Nb reaction the present work reports the first measurement of this reaction cross section. Both reaction cross sections are compared to theoretical calculations and a very good agreement with the standard non-smoker model is observed.

In an effort to investigate the production of ${}^{74}$Se in $p$-process nucleosynthesis, the ${}^{74}$Ge($p$,$\ensuremath{\gamma}$)${}^{75}$As reaction cross section was measured in the relevant energy range of ${E}_{p}=1.6$--4.2 MeV. The measurements were carried out using the NSCL SuN detector at the University of Notre Dame. The results are in good agreement with previous work, extending the measurements to both lower and higher energies. The measurements are compared to theoretical predictions using the non-smoker and talys nuclear reaction codes. New and improved reaction rates are offered, and these reaction rates are used in a 25M${}_{\ensuremath{\bigodot}}$ Type II Supernova model to study their impact on the production of ${}^{74}$Se.

A systematic study of the radiative proton capture reaction for all stable nickel isotopes is presented. The results were obtained using 2.0 - 6.0 MeV protons from the 11 MV tandem Van de Graaff accelerator at the University of Notre Dame. The \gamma-rays were detected by the NSCL SuN detector utilising the \gamma-summing technique. The results are compared to a compilation of earlier measurements and discrepancies between the previous data are resolved. The experimental results are also compared to the theoretical predictions obtained using the NON-SMOKER and SMARAGD codes. Based on these comparisons an improved set of astrophysical reaction rates is proposed for the (p,\gamma) reactions on the stable nickel isotopes as well as for the 56Ni(p,\gamma)57Cu reaction.

The fusion excitation function of 60 Ni + 100 Mo has been measured from above the Coulomb barrier down to a cross section around 2 μb, looking for coupling and hindrance effects in this soft medium-mass system with positive Q-values for several neutron transfer channels. A comparison is made with previous results for 64 Ni + 100 Mo where no Q > 0 transfer channels exist and the hindrance effect is quite clear. The two excitation functions are very similar, as well as the corresponding logarithmic derivatives showing analogous saturations below the barrier. It appears that transfer couplings to Q > 0 channels seem to play a marginal role near and below the barrier for 60 Ni + 100 Mo , even if measurements of cross sections lower than 1 μb would be needed also for this system. Coupled-channels calculations confirm these observations and indicate that multi-phonon excitations dominate the fusion dynamics in the whole measured energy range.

The fusion excitation function of ${}^{32}$S + ${}^{48}$Ca has been experimentally studied in a wide energy range, from above the Coulomb barrier down to cross sections in the sub-$\ensuremath{\mu}$b region. The measurements were done at INFN--Laboratori Nazionali di Legnaro, using the ${}^{32}$S beam from the XTU Tandem accelerator. The excitation function has a smooth behavior below the barrier, and no evident hindrance character shows up in the measured energy region. The fusion barrier distribution has a peculiar shape with two distinct peaks of similar height, lower and higher than the Aky\"uz-Winther barrier. Coupled-channels calculations using the M3Y + repulsion potential are presented for this system and for ${}^{36}$S + ${}^{48}$Ca. The results of these calculations give a good account of the data, and indicate the influence of one- and two-nucleon transfer channels with positive $Q$ values, which are only open for ${}^{32}$S + ${}^{48}$Ca.

The fusion excitation function of ${}^{40}\mathrm{Ca}+{}^{40}\mathrm{Ca}$ has been measured from well above the Coulomb barrier, down to low energies where the cross section is as small as $\ensuremath{\simeq}$20 $\ensuremath{\mu}$b, and the astrophysical $S$ factor possibly reaches a maximum vs energy. The results of coupled-channels calculations using the $\mathrm{M}3\mathrm{Y}+\mathrm{repulsion}$ potential are presented. A detailed comparison is made with recently published data on the fusion of ${}^{40}\mathrm{Ca}+{}^{48}\mathrm{Ca}$ and of ${}^{48}\mathrm{Ca}+{}^{48}\mathrm{Ca}$, including the excitation functions, their low-energy slopes and the barrier distributions. The presence of the fusion hindrance phenomenon in all cases is pointed out, as well as the influence of the strong octupole excitation in ${}^{40}$Ca and of nucleon transfer channels with positive $Q$ values in ${}^{40}\mathrm{Ca}+{}^{48}\mathrm{Ca}$.

Fusion data for $^{13}$C+$^{13}$C, $^{12}$C+$^{13}$C and $^{12}$C+$^{12}$C are analyzed by coupled-channels calculations that are based on the M3Y+repulsion, double-folding potential. The fusion is determined by ingoing-wave-boundary conditions (IWBC) that are imposed at the minimum of the pocket in the entrance channel potential. Quadrupole and octupole transitions to low-lying states in projectile and target are included in the calculations, as well as mutual excitations of these states. The effect of one-neutron transfer is also considered but the effect is small in the measured energy regime. It is shown that mutual excitations to high-lying states play a very important role in developing a comprehensive and consistent description of the measurements. Thus the shapes of the calculated cross sections for $^{12}$C+$^{13}$C and $^{13}$C+$^{13}$C are in good agreement with the data. The fusion cross sections for $^{12}$C+$^{12}$C determined by the IWBC are generally larger than the measured cross sections but they are consistent with the maxima of some of the observed peak cross sections. They are therefore expected to provide an upper limit for the extrapolation into the low-energy regime of interest to astrophysics., Comment: 34 pages, 17 figures

A measurement of the $\ensuremath{\beta}$-delayed $\ensuremath{\alpha}$ decay of $^{16}\mathrm{N}$ using a set of twin ionization chambers is described. Sources were made by implantation, using a $^{16}\mathrm{N}$ beam produced via the In-Flight Technique. The energies and emission angles of the $^{12}\mathrm{C}$ and $\ensuremath{\alpha}$ particles were measured in coincidence and very clean $\ensuremath{\alpha}$ spectra, down to energies of $450$ keV, were obtained. The structure of the spectra from this experiment is in good agreement with results from previous measurements. An analysis of our data with the same input parameters as used in earlier studies gives ${S}_{E1}(300)=86\ifmmode\pm\else\textpm\fi{}22$ keVb for the $E1$ component of the $S$-factor. This value is in excellent agreement with results obtained from various direct and indirect measurements. In addition, the influence of new measurements including the phase shift data from Tischhauser et al. on the value of ${S}_{E1}(300)$ is discussed.

Fusion evaporation cross sections for the {sup 27}Al+{sup 45}Sc (Q=9.63 MeV) system are measured down to about 300 nb. Deviations from standard coupled-channels calculations were observed in this system at the lowest energies. The steep fall-off of the fusion cross sections can be reproduced by calculations using a shallow potential model, which was originally developed to explain the hindrance behavior of heavy-ion fusion in medium-mass systems with negative Q values. Comparisons of the hindrance behavior between the present experiment and other systems, for example, {sup 28}Si+{sup 30}Si (Q=14.3 MeV) and {sup 36}S+{sup 48}Ca (Q=7.55 MeV) are presented.

We have studied the neutron-transfer reactions {sup 11,12}B(d,p){sup 12,13}B in inverse kinematics to obtain information about the neutron-capture reactions {sup 11,12}B(n,{gamma}). These capture reactions are suggested to play a role in seeding r-process nucleosynthesis through the production of light, neutron-rich nuclei. The neutron spectroscopic factors of the states in {sup 12,13}B were deduced and the branching ratio of the neutron-unbound state at E{sub X}=3.389 MeV in {sup 12}B was obtained to provide the ratio of partial widths, {Gamma}{sub n}/{Gamma}{sub {gamma}}. The reaction rates for {sup 11,12}B(n,{gamma}) are estimated for direct captures and resonant captures and compared with previous compilations. The astrophysical implications, especially for neutrino-driven wind models in core-collapse supernovae, are discussed in the r-process network framework using our updated reaction rates.

The measurement of the excitation function for fusion evaporation reactions in the system $^{40}\mathrm{Ca}+^{48}\mathrm{Ca}$ ($Q=$ 4.56 MeV) has been extended downward by two orders of magnitude with respect to previous cross section data. A first indication of an $S$-factor maximum in a system with a positive $Q$ value has been observed. In addition a correlation between fusion hindrance and neutron excess $N\ensuremath{-}Z$ has been found for the Ca $+$ Ca, Ni $+$ Ni, and Ca $+$ Zr systems.

We report on a study of the structure of the unbound nucleus {sup 7}He utilizing the proton-removal reaction {sup 2}H({sup 8}Li,{sup 3}He){sup 7}He. Combining the present results with those of our prior measurements of the neutron-adding reaction {sup 2}H({sup 6}He,p){sup 7}He, a consistent picture emerges for the low-lying excitations in {sup 7}He. Specifically, the negative-parity sequence of resonances, in order of excitation energies, is consistent with 3/2{sup -},1/2{sup -}, and 5/2{sup -}. The stable-beam reactions {sup 2}H({sup 7}Li,t){sup 6}Li and {sup 2}H({sup 7}Li,{sup 3}He){sup 6}He were also measured. The results are compared with the predictions of nuclear structure models, including those of ab initio quantum Monte Carlo calculations.

The capture cross sections and fission fragment angular distributions were measured for the reaction of $^{50}\mathrm{Ti}$ with $^{208}\mathrm{Pb}$ at center of mass projectile energies (${E}_{\mathrm{c}.\mathrm{m}.}$) of 183.7, 186.2, 190.2, 194.2, and 202.3 MeV (${E}^{*}=14.2$, 16.6, 20.6, 24.7, and 32.7 MeV). From fitting the backward angle fragment angular distributions, the cross sections for quasifission and fusion-fission and ${P}_{\mathrm{CN}}$, the probability that the colliding nuclei go from the contact configuration to inside the fission saddle point, were deduced. These quantities, along with the known values of the evaporation residue production cross sections for this reaction, were used to deduce values of the survival probabilities, ${W}_{\mathrm{sur}}$, for this reaction as a function of excitation energy. The deduced values of ${P}_{\mathrm{CN}}$ and ${W}_{\mathrm{sur}}$ and their dependence on excitation energy differ from some current theoretical predictions of these quantities.

Precision measurements were carried out to test the similarities between the ground states of $^{76}\mathrm{Ge}$ and $^{76}\mathrm{Se}$. The extent to which these two nuclei can be characterized as consisting of correlated pairs of neutrons in a BCS-like ground state was studied. The pair removal $(p,t)$ reaction was measured at the far forward angle of ${3}^{\ifmmode^\circ\else\textdegree\fi{}}$. The relative cross sections are consistent (at the 5% level) with the description of these nuclei in terms of a correlated pairing state outside the $N=28$ closed shells with no pairing vibrations. Data were also obtained for $^{74}\mathrm{Ge}$ and $^{78}\mathrm{Se}$.

We have studied the properties of low-lying levels in {sup 7}He using the {sup 2}H({sup 6}He,p){sup 7}He reaction at 11.5 MeV/u. This reaction probes the {sup 6}He{sub g.s.}+n character of states in {sup 7}He. The ground state was populated with a spectroscopic factor comparable to that obtained from ab initio calculations, supporting the tentative spin-parity assignment of 3/2{sup -} in the literature. In addition to the ground state, a broad structure is observed between E{sub X}=2-3 MeV, the excitation-energy range expected for the 1/2{sup -} state in {sup 7}He. No evidence was found for a lower-lying, first-excited state reported recently.

The excitation function for the fusion-evaporation reaction 64Ni+100Mo has been measured down to a cross-section of ~5 nb. Extensive coupled-channels calculations have been performed, which cannot reproduce the steep fall-off of the excitation function at extreme sub-barrier energies. Thus, this system exhibits a hindrance for fusion, a phenomenon that has been discovered only recently. In the S-factor representation introduced to quantify the hindrance, a maximum is observed at E_s=120.6 MeV, which corresponds to 90% of the reference energy E_s^ref, a value expected from systematics of closed-shell systems. A systematic analysis of Ni-induced fusion reactions leading to compound nuclei with mass A=100-200 is presented in order to explore a possible dependence of the fusion hindrance on nuclear structure., 10 pages, 9 figures, Submitted to Phys. Rev. C

$^{13}\mathrm{N}(p,\ensuremath{\gamma})^{14}\mathrm{O}$ is one of the key reactions which trigger the onset of the hot CNO cycle. This transition occurs when the proton capture rate on $^{13}\mathrm{N}$ is faster, due to increasing stellar temperature $(\ensuremath{\geqslant}{10}^{8}\phantom{\rule{0.3em}{0ex}}\mathrm{K})$, than the $^{13}\mathrm{N}$ $\ensuremath{\beta}$-decay rate. The rate of this reaction is dominated by the resonant capture through the first excited state of $^{14}\mathrm{O}$ $({E}_{r}=0.528\phantom{\rule{0.3em}{0ex}}\text{MeV})$. However, through constructive interference, direct capture below the resonance makes a non-negligible contribution to the reaction rate. We have determined this direct contribution by measuring the asymptotic normalization coefficient for $^{14}\mathrm{O}\ensuremath{\rightarrow}^{13}\mathrm{N}+p$. In our experiment, an $11.8\phantom{\rule{0.3em}{0ex}}\text{MeV}∕\text{nucleon}$ $^{13}\mathrm{N}$ radioactive beam was used to study the $^{14}\mathrm{N}(^{13}\mathrm{N},^{14}\mathrm{O})^{13}\mathrm{C}$ peripheral transfer reaction, and the asymptotic normalization coefficient, ${({C}_{{p}_{1∕2}}^{^{14}\mathrm{O}})}^{2}=29.0\ifmmode\pm\else\textpm\fi{}4.3\phantom{\rule{0.3em}{0ex}}{\text{fm}}^{\ensuremath{-}1}$, was extracted from the measured cross section. The radiative capture cross section was estimated using an $R$-matrix approach with the measured asymptotic normalization coefficient and the latest resonance parameters. We find the $S$ factor for $^{13}\mathrm{N}(p,\ensuremath{\gamma})^{14}\mathrm{O}$ to be larger than previous estimates. Consequently, the transition from the cold to hot CNO cycle for novae would be controlled by the slowest proton capture reaction $^{14}\mathrm{N}(p,\ensuremath{\gamma})^{15}\mathrm{O}$.

Fusion-evaporation reactions induced by $110\phantom{\rule{0.3em}{0ex}}\text{MeV}$ $^{11}\mathrm{B}$ and radioactive $^{11}\mathrm{C}$ on $^{87}\mathrm{Rb}$ targets have been studied by measuring evaporation residue--light particle coincidences. The proton to $\ensuremath{\alpha}$ particle ratio in each reaction has been derived and compared with predictions from statistical model calculations. These calculations account rather well for the experimental data, when a small empirical adjustment of the emission barrier is performed, in agreement with earlier results. No evidence is found for predicted temperature and isospin modification of the binding energies. The possibility of a further study of isospin and temperature dependent effects in fusion-evaporation reactions with radioactive beams is discussed.

We are developing a technique of ultra-sensitive detection of the p-process 146Sm nuclide by accelerator mass spectrometry. 146Sm was produced via the reactions (γ,n), (p,2ne) and (n,2n) on 147Sm. Preliminary results demonstrate for the first time the capability of identifying unambiguously 146Sm through separation and discrimination of its stable 146Nd isobar and other background ions. We consider applying the detection method to an independent determination of 146Sm half-life and to the measurements of cross sections of low-energy nuclear reactions producing long-lived nuclides in the vicinity of 146Sm.