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Objective/Background: Slow wave activity (SWA) and sigma frequency activity (SFA) are hallmarks of NREM sleep EEG and important indicators of neural plasticity, development of the central nervous system, and cognition. However, little is known about the factors that modulate these sleep EEG activities, especially in small children. Patients/methods: We analyzed the power spectral densities of SWA (1–4 Hz) and SFA range (10–15 Hz) from six EEG derivations of 56 infants (8 months) and 60 toddlers (24 months) during their all-night sleep and during the first and the last half of night sleep. The spectral values were compared between the four seasons. Results: In the spring group of infants, compared with the darker seasons, SFA was lower in the centro-occipital EEG derivations during both halves of the night. The SWA findings of the infants were restricted to the last half of the night (SWA2) and frontally, where SWA2 was higher during winter than spring. The toddlers presented less frontal SWA2 during winter compared with autumn. Both age groups showed a reduction in both SWA and SFA towards the last half of the night. Conclusions: The sleep EEG spectral power densities are more often associated with seasons in infants’ SFA range. The results might stem from seasonally changing light exposure, but the exact mechanism warrants further study. Moreover, contrary to the adult-like increment of SFA, the SFA at both ages was lower at the last part of the night sleep. This suggests different regulation of spindle activity in infants and toddlers. publishedVersion

The astrophysical $^{25}\mathrm{Al}(p,\ensuremath{\gamma})\phantom{\rule{0.16em}{0ex}}^{26}\mathrm{Si}$ reaction represents one of the key remaining uncertainties in accurately modeling the abundance of radiogenic $^{26}\mathrm{Al}$ ejected from classical novae. Specifically, the strengths of key proton-unbound resonances in $^{26}\mathrm{Si}$, that govern the rate of the $^{25}\mathrm{Al}(p,\ensuremath{\gamma})$ reaction under explosive astrophysical conditions, remain unsettled. Here, we present a detailed spectroscopy study of the $^{26}\mathrm{Si}$ mirror nucleus $^{26}\mathrm{Mg}$. We have measured the lifetime of the ${3}^{+}$, 6.125-MeV state in $^{26}\mathrm{Mg}$ to be $19(3)\phantom{\rule{0.28em}{0ex}}\mathrm{fs}$ and provide compelling evidence for the existence of a ${1}^{\ensuremath{-}}$ state in the $T=1,\phantom{\rule{0.28em}{0ex}}A=26$ system, indicating a previously unaccounted for $\ensuremath{\ell}=1$ resonance in the $^{25}\mathrm{Al}(p,\ensuremath{\gamma})$ reaction. Using the presently measured lifetime, together with the assumption that the likely ${1}^{\ensuremath{-}}$ state corresponds to a resonance in the $^{25}\mathrm{Al}+p$ system at 435.7(53) keV, we find considerable differences in the $^{25}\mathrm{Al}(p,\ensuremath{\gamma})$ reaction rate compared to previous works. Based on current nova models, we estimate that classical novae may be responsible for up to $\ensuremath{\approx}15%$ of the observed galactic abundance of $^{26}\mathrm{Al}$.

After commissioning the AstroBox2 detector has been used already for several physics experiments. During some of the experiments systematic effects in the measured decay spectra have been observed and related to gain shifts due to the environment, the chemical nature of the isotope under investigation, and to the beam implantation rate. In this article we report the observations and influence of these systematic effects that may well be of interest to other similar experiments with stopped rare isotope beams and detectors relying on gas amplification. Full characterization and understanding of these effects call for further systematic studies.

Background: The Efimov effect is a universal phenomenon in physics whereby three-body systems are stabilized via the interaction of an unbound two-body subsystems. A hypothetical state in $^{12}\mathrm{C}$ at 7.458-MeV excitation energy, comprising a loose structure of three $\ensuremath{\alpha}$ particles in mutual two-body resonance, has been suggested in the literature to correspond to an Efimov state in nuclear physics. The existence of such a state has not been demonstrated experimentally.Purpose: Using a combination of $\ensuremath{\gamma}$ spectroscopy, charged-particle spectroscopy, and astrophysical rate calculations allowing for strict limits on the existence of such a state to been established here.Method: Using the combined data sets from two recent experiments, one with the TexAT (Texas Active Target) TPC (Time Projection Chamber) to measure $\ensuremath{\alpha}$ decay and the other with Gammasphere to measure $\ensuremath{\gamma}$ decay of states in $^{12}\mathrm{C}$ populated by $^{12}\mathrm{N}$ and $^{12}\mathrm{B}\phantom{\rule{4pt}{0ex}}\ensuremath{\beta}$ decay, respectively, we achieve high sensitivity to states in close proximity to the $\ensuremath{\alpha}$ threshold in $^{12}\mathrm{C}$.Results: No evidence of a state at 7.458 MeV is seen in either data set. Using a likelihood method, the 95% confidence limit $\ensuremath{\gamma}$-decay branching ratio is determined as a function of the $\ensuremath{\beta}$-decay feeding strength relative to the Hoyle state. In parallel, calculations of the $3\ensuremath{\alpha}$ reaction rate show the inclusion of the Efimov corresponds to a large increase in the reaction rate around $5\ifmmode\times\else\texttimes\fi{}{10}^{7}$ K.Conclusion: From decay spectroscopy---at the 95% confidence limit, the Efimov state cannot exist at 7.458 MeV with any $\ensuremath{\gamma}$-decay branching ratio unless the $\ensuremath{\beta}$ strength is less than 0.7% of the Hoyle state. This limit is evaluated for a range of different excitation energies and the results are not favorable for existence of the hypothetical Efimov state in $^{12}\mathrm{C}$. Furthermore, the $3\ensuremath{\alpha}$ reaction rate with the inclusion of a state between 7.43 and 7.53 MeV exceeds the rate required for stars to undergo the red giant phase.

Background: The structure of the Hoyle state, a highly $\ensuremath{\alpha}$-clustered state at 7.65 MeV in $^{12}\mathrm{C}$, has long been the subject of debate. Understanding if the system comprises of three weakly interacting $\ensuremath{\alpha}$ particles in the $0s$ orbital, known as an $\ensuremath{\alpha}$-condensate state, is possible by studying the decay branches of the Hoyle state.Purpose: The direct decay of the Hoyle state into three $\ensuremath{\alpha}$ particles, rather than through the $^{8}\mathrm{Be}$ ground state, can be identified by studying the energy partition of the three $\ensuremath{\alpha}$ particles arising from the decay. This paper provides details on the breakup mechanism of the Hoyle stating using a new experimental technique.Method: By using $\ensuremath{\beta}$-delayed charged-particle spectroscopy of $^{12}\mathrm{N}$ using the Texas active target time-projection chamber, a high-sensitivity measurement of the direct $3\ensuremath{\alpha}$ decay ratio can be performed without contributions from pileup events.Results: A Bayesian approach to understanding the contribution of the direct components via a likelihood function shows that the direct component is $l0.043%$ at the 95% confidence level. This value is in agreement with several other studies, and, here, we can demonstrate that a small nonsequential component with a decay fraction of about ${10}^{\ensuremath{-}4}$ is most likely.Conclusion: The measurement of the nonsequential component of the Hoyle state decay is performed in an almost medium-free reaction for the first time. The derived upper limit is in agreement with previous studies and demonstrates sensitivity to the absolute branching ratio. Further experimental studies would need to be combined with robust microscopic theoretical understanding of the decay dynamics to provide additional insight into the idea of the Hoyle state as an $\ensuremath{\alpha}$ condensate.

This study examines how parents of pediatric patients might differ in their views and attitudes towards genetic technology and information when compared to adult patients. There is surprisingly little evidence on how parents compare to other parts of population in their attitudes. Previous empirical studies often relate health-related preferences and attitudes to factors such as age, education, and income instead of parental status, thus evading comparison of parents to others as health-related decision makers. Findings related to the parental status can be useful when implementing genetic technology in clinical practice. We conducted a survey of views on genetic technology and information for groups of adult neurology patients (n = 68) and parents of pediatric neurology patients (n = 31) to shed some light on this issue. In addition to our own survey instrument, we conducted other surveys to gain insight on psychosocial factors that might affect these attitudes. The results suggest that parents are more concerned about their children’s genetic risk factors when compared to the attitudes of adult patients about their own risk. For both groups, negative emotional state was associated with more concerns towards genetic information. Our study provides insights on how parental views might affect the acceptance of genetic technology and information. Electronic supplementary material The online version of this article (10.1007/s12687-020-00462-8) contains supplementary material, which is available to authorized users.

We have measured the branching ratio for the superallowed ${0}^{+}\ensuremath{\rightarrow}$ ${0}^{+}\phantom{\rule{4pt}{0ex}}\ensuremath{\beta}$ transition from $^{34}\mathrm{Ar}$ to be 0.9448(8), and determined its $ft$ value to be 3058.1(28) s, a result with $\ifmmode\pm\else\textpm\fi{}0.09$% precision, which is a factor of 3 improvement over the previous result based on current world data. The $ft$-value ratio for the mirror pair of superallowed transitions $^{34}\mathrm{Ar}$ $\ensuremath{\rightarrow}^{34}\mathrm{Cl}$ and $^{34}\mathrm{Cl}$ $\ensuremath{\rightarrow}^{34}\mathrm{S}$ becomes the most precise yet measured and, in a sensitive test of the method used to calculate the isospin-symmetry-breaking correction, ${\ensuremath{\delta}}_{C}$, it agrees well with the ratio as calculated with Woods-Saxon radial wave functions. This confirms the method used in the most recent survey of superallowed decays to extract ${V}_{\text{ud}}$, the up-down quark-mixing element of the Cabibbo-Kobayashi-Maskawa matrix. In addition, our branching-ratio results for the four observed Gamow-Teller branches to ${1}^{+}$ states in $^{34}\mathrm{Cl}$ are shown to agree well with shell-model calculations based on the same effective interactions that were used in the determination of ${\ensuremath{\delta}}_{C}$.

Background: Clustering plays an important role in the structure of $^{10}\mathrm{Be}$. Exotic molecular-like configurations, such as $\ensuremath{\alpha}$:$2n$:$\ensuremath{\alpha}$, have been suggested at relatively low excitation energies.Purpose: To search for the high-spin states that may belong to the molecular-like $\ensuremath{\alpha}$:$2n$:$\ensuremath{\alpha}$ configuration in $^{10}\mathrm{Be}$.Method: Measuring excitation functions for $^{6}\mathrm{He}+\phantom{\rule{0.16em}{0ex}}\ensuremath{\alpha}$ scattering, populating states in the excitation energy range from 4.5 MeV to 8 MeV in $^{10}\mathrm{Be}$ using a $^{6}\mathrm{He}$ rare-isotope beam and a thick helium gas target.Results: No new excited states in $^{10}\mathrm{Be}$ have been observed. Stringent limits on the possible degree of $\ensuremath{\alpha}$-clustering of the hypothetical yrast ${6}^{+}$ state have been obtained.Conclusions: The high-spin members of the $\ensuremath{\alpha}$:$2n$:$\ensuremath{\alpha}$ molecular-like rotational band configuration, that is considered to have a ${0}^{+}$ band head at 6.18 MeV, either do not exist or have small overlap with the $^{6}\mathrm{He}$(g.s.)$+\ensuremath{\alpha}$ channel.

The astrophysical s-process is one of the two main processes forming elements heavier than iron. A key outstanding uncertainty surrounding s-process nucleosynthesis is the neutron flux generated by the Ne 22 ( α , n ) 25 Mg reaction during the He-core and C-shell burning phases of massive stars. This reaction, as well as the competing Ne 22 ( α , γ ) 26 Mg reaction, is not well constrained in the important temperature regime from ∼0.2–0.4 GK, owing to uncertainties in the nuclear properties of resonances lying within the Gamow window. To address these uncertainties, we have performed a new measurement of the Ne 22 ( Li 6 , d ) 26 Mg reaction in inverse kinematics, detecting the outgoing deuterons and Mg 25 , 26 recoils in coincidence. We have established a new n / γ decay branching ratio of 1.14 ( 26 ) for the key E x = 11.32 MeV resonance in Mg 26 , which results in a new ( α , n ) strength for this resonance of 42 ( 11 ) μ eV when combined with the well-established ( α , γ ) strength of this resonance. We have also determined new upper limits on the α partial widths of neutron-unbound resonances at E x = 11.112 , 11.163, 11.169, and 11.171 MeV. Monte-Carlo calculations of the stellar Ne 22 ( α , n ) 25 Mg and Ne 22 ( α , γ ) 26 Mg rates, which incorporate these results, indicate that both rates are substantially lower than previously thought in the temperature range from ∼0.2–0.4 GK.

We have measured the half-life of $^{34}\mathrm{Ar}$, the parent of a superallowed ${0}^{+}\ensuremath{\rightarrow}{0}^{+}$ $\ensuremath{\beta}$ transition, to be 0.84646(35) s. With a precision of 0.04%, this result is an essential ingredient needed to complete a third pair of mirror superallowed transitions, $^{34}\mathrm{Ar}\phantom{\rule{4pt}{0ex}}\ensuremath{\rightarrow}\phantom{\rule{4pt}{0ex}}^{34}\mathrm{Cl}$ and $^{34}\mathrm{Cl}\phantom{\rule{4pt}{0ex}}\ensuremath{\rightarrow}\phantom{\rule{4pt}{0ex}}^{34}\mathrm{S}$, the ratio of whose $ft$ values would provide the most sensitive test yet of the isospin-symmetry-breaking corrections used to obtain ${V}_{ud}$. In a sequence repeated thousands of times, we implanted a very pure $^{34}\mathrm{Ar}$ beam into tape for 0.7 s, and then rapidly transported the collected source to a shielded $4\ensuremath{\pi}$ proportional gas counter, which detected the decay positrons from the combined decays of $^{34}\mathrm{Ar}$ and its daughter $^{34}\mathrm{Cl}$. The data were analyzed as a linked parent-daughter pair. Our new result replaces one we published 13 years ago.

β -delayed charged-particle emission is a sensitive probe of three-body decays in light nuclei. Time Projection Chambers (TPCs) offer a significant advantage over traditional charged-particle spectroscopy techniques due to a low-energy threshold and a high-geometric efficiency ( ≈ 4 π ) which are essential for use with radioactive ion beams where the beam intensities are limited. The technique for high-sensitivity spectroscopy of β -delayed charged-particle emission is shown to be possible using the Texas Active Target (TexAT) TPC in conjunction with the General Electronics for TPCs (GET) system. The benchmark case studied was that of 12 N β -decay to the first α -unbound state in 12 C , the Hoyle state. Half-life and branching ratio measurements are presented and are in good agreement with previous studies. The efficacy of using TPCs to study such a near-threshold state and disentangle the three-body dynamics of the decay products is demonstrated.

The TexAT (Texas Active Target) detector is a new active-target time projection chamber (TPC) that was built at the Cyclotron Institute Texas A$\&$M University. The detector is designed to be of general use for nuclear structure and nuclear astrophysics experiments with rare isotope beams. TexAT combines a highly segmented Time Projection Chamber (TPC) with two layers of solid state detectors. It provides high efficiency and flexibility for experiments with low intensity exotic beams, allowing for the 3D track reconstruction of the incoming and outgoing particles involved in nuclear reactions and decays., 18 pages, 36 figures

The average prompt-fission-neutron multiplicity $\overline{\ensuremath{\nu}}$ is of significance in the areas of nuclear theory, nuclear nonproliferation, and nuclear energy. In this work, the surrogate-reaction method has been used for the first time to indirectly determine $\overline{\ensuremath{\nu}}$ for $^{239}\mathrm{Pu}(n,f)$ via $^{240}\mathrm{Pu}(\ensuremath{\alpha},{\ensuremath{\alpha}}^{\ensuremath{'}}f)$ reactions. A $^{240}\mathrm{Pu}$ target was bombarded with a beam of 53.9-MeV $\ensuremath{\alpha}$ particles. Scattered $\ensuremath{\alpha}$ particles, fission products, and neutrons were measured with the NeutronSTARS detector array. Values of $\overline{\ensuremath{\nu}}$ were obtained for a continuous range of equivalent incident neutron energies between 0.25 and 26.25 MeV, and the results agree well with direct neutron measurements.

NeutronSTARS ( Neutron - S ilicon T elescope A rray for R eaction S tudies) consists of 2.2-tons of gadolinium-doped liquid scintillator for neutron detection and large area silicon detectors for charged particle identification. This detector array is intended for low-energy-nuclear-reaction measurements that result in the emission of neutrons such as ( n , x n ) and fission. This paper describes the NeutronSTARS experimental setup, calibration, and the array’s response to neutral and charged particles.

Hyperion is a new high-efficiency charged-particle γ -ray detector array which consists of a segmented silicon telescope for charged-particle detection and up to fourteen high-purity germanium clover detectors for the detection of coincident γ rays. The array will be used in nuclear physics measurements and Stockpile Stewardship studies and replaces the STARLiTeR array. This article discusses the features of the array and presents data collected with the array in the commissioning experiment.

Background: Level structure of the most neutron-deficient nucleon-bound carbon isotope, $^{9}\mathrm{C}$, is not well known. Definitive spin-parity assignments are only available for two excited states. No positive-parity states have been conclusively identified so far and the location of the $sd$ shell in the $A=9, T=3/2$ isospin quadruplet is not known.Purpose: We have studied the level structure of exotic nucleus $^{9}\mathrm{C}$ at excitation energies below 6.4 MeV.Methods: Excited states in $^{9}\mathrm{C}$ were populated in $^{8}\mathrm{B}+p$ resonance elastic scattering and excitation functions were measured using the active target approach.Results: Two excited states in $^{9}\mathrm{C}$ were conclusively observed, and $R$-matrix analysis of the excitation functions was performed to make the spin-parity assignments. The first positive-parity state in the $A=9, T=3/2$ nuclear system, the $5/{2}^{+}$ resonance at 4.3 MeV, has been identified.Conclusions: The new $5/{2}^{+}$ state at 4.3 MeV in $^{9}\mathrm{C}$ is a single-particle $\ensuremath{\ell}=0$ broad resonance and it determines the energy of the $2s$ shell. The $2s$ shell in this exotic nucleus appears well within the region dominated by the $p$-shell states.

Superallowed $\ensuremath{\beta}$ decay is an important tool in characterizing the vector component of the weak interaction. Precise $\ensuremath{\beta}$-decay results presently give the best measurement of the up-down quark weak-mixing element, ${V}_{u\phantom{\rule{0}{0ex}}d}$. This new result completes the measurement of a second set of superallowed mirror transitions (${}^{26}$Si-${}^{26m}$Al and ${}^{26m}$Al-${}^{26}$Mg in this case) and has the precision to constrain the theoretical isospin-symmetry-breaking corrections needed in the extraction of ${V}_{u\phantom{\rule{0}{0ex}}d}$.

A MICROMEGAS detection amplifier has been incorporated into the design of the TAMU MDM focal plane detector with the purpose of improving the energy resolution and thus, the particle identification. Beam tests showed a factor of 2 improvement over the original design, from 10-12% to 4-6%, for ions with A, 8 pages, 13 figures

Fission neutron multiplicity data are imperative for nuclear models that support criticality safety, nuclear nonproliferation, and stockpile stewardship. This work presents the first experimental measurement to determine the average neutron multiplicity ($\overline{\ensuremath{\nu}}$) and the neutron multiplicity distribution using a surrogate reaction. $^{241}\mathrm{Pu}$ has a short half-life of 14.3 yr. To circumvent experimental difficulties, inelastic scattering of 53.96-MeV $\ensuremath{\alpha}$ particles on $^{242}\mathrm{Pu}$ served as a surrogate for $^{241}\mathrm{Pu}(n,f)$. The present text reports and discusses the average neutron multiplicity, in addition to the neutron multiplicity moments and distribution for equivalent neutron energies up to 20 MeV. The $\overline{\ensuremath{\nu}}$ measured in this experiment agrees with previous measurements until 12 MeV, where discrepancies arise due to preequilibrium neutron emission.

The \(^{22}\)Ne(\(^6\)Li,d) reaction at sub-Coulomb energy was performed to measure partial \(\alpha \)-widths of near \(\alpha \)-threshold resonances in \(^{26}\)Mg. New constrains on the \(^{22}\)Ne(\(\alpha \),n) reaction rate have been obtained and consequences on the final abundances for some s-process isotopes are discussed.

The $\ensuremath{\gamma}$-strength functions and level densities in the quasicontinuum of $^{147,149}\mathrm{Sm}$ isotopes have been extracted from particle-$\ensuremath{\gamma}$ coincidences using the Oslo method. The nuclei of interest were populated via $(p,d)$ reactions on pure $^{148,150}\mathrm{Sm}$ targets and the reaction products were recorded by the Hyperion array. An upbend in the low-energy region of the $\ensuremath{\gamma}\mathrm{SF}$ has been observed. The systematic analysis of the $\ensuremath{\gamma}\mathrm{SF}$ for a range of Sm isotopes highlights the interplay between scissors mode and the upbend. Shell-model calculations show reasonable agreement with the experimental $\ensuremath{\gamma}\mathrm{SFs}$ and confirm the correspondence between the upbend and scissors mode.

The Gaseous Detector with Germanium Tagging (GADGET) is a new detection system devoted to the measurement of weak, low-energy β -delayed proton decays relevant for nuclear astrophysics studies. It is comprised of a new gaseous Proton Detector equipped with a Micromegas readout for charged particle detection, surrounded by the existing Segmented Germanium Array (SeGA) for the high-resolution detection of the prompt γ -rays. In this work we describe in detail for the first time the design, construction, and operation of the GADGET system, including performance of the Proton Detector. We present the results of a recent commissioning experiment performed with 25 Si beam at the National Superconducting Cyclotron Laboratory (NSCL). GADGET provided low-background, low-energy β -delayed proton detection with efficiency above 95%, and relatively good efficiency for proton-gamma coincidences (2.7% at 1.37 MeV).

Rapid shape evolutions near A = 100 are now the focus of much attention in nuclear science. Much of the recent work has been centered on isotopes with Z

International audience; The 9C breakup was studied during the SAMURAI29R1 experiment through inclusive and exclusive measurements at energies around 160 AMeV for 9C, in order to evaluate the astrophysical S18 factor for the inverse process 8B(p,γ)9C at energies in the region of astrophysical interest. The radiative proton capture on 8B is important in the hot pp chains, in explosive Hydrogen burning (ppIV and rapI), at temperatures between 0.05 < T9 < 1 K, as possible alternative paths across the A = 8 mass gap. Another goal of this experiment was a detailed study of the breakup reaction mechanism. During the experiment the nuclear breakup process was studied using a natural C target with 425 µm thickness and the Coulomb dissociation by using a natural Pb target with 150 µm thickness. The reaction products were tracked simultaneously using a system of position sensitive Si detectors and in total 1024 output channels were read out by using new dual gain preamplifiers (DGP) specially designed for the experiments of the HI-p collaboration. The SAMURAI29R1 experiment was carried out during the SAMURAI 18Oxygen 2018 Spring campaign and it is part of the HI-p collaboration together with another three experiments. Performances of the setup used and first results of the analysis are presented.

Direct measurements of the total fusion cross section for B 8 + 40 Ar were achieved with the active target technique. The fusion excitation function was extracted at energies near the Coulomb barrier. The cross section is well described by a coupled reaction channels calculation. The data were compared with previous B 8 fusion experiments on Si 28 and Ni 58 targets. No evidence of striking enhancement of the total fusion cross section at near the Coulomb barrier, that was previously reported for the B 8 + 58 Ni system, was observed in these direct measurements. The present data are systematically consistent with the results for B 8 + 28 Si at higher energies and with other weakly-bound systems at near-barrier energies.

Efficient suppression of β-background is essential for studies of low-energy β-delayed charged particle decays of astrophysical interest. A promising method for such studies has been a micro pattern gas amplifier detector where the sample is implanted into the gas volume and the decays that follow are observed with high gain and signal to noise ratio. An upgraded version of the original AstroBox detector has been built and commissioned at Texas A&M University. Here a description of the new AstroBox2 detector is given, selected results from the commissioning tests are presented, and future perspectives discussed.

A gridded ionization chamber used as a focal plane detector at the back of the TAMU-MDM spectrometer was modified to use MicroMegas technology for the purpose of improving energy resolution and particle identification. The upgraded system was tested in experimental conditions with several heavy-ion beams at 12 MeV/u and found to achieve resolutions between 3.2% and 4.8%. This is a significant improvement over the previous performance of 10–15% obtained using the existing, conventional ionization chambers.

Electricity distribution is a prime example of local monopoly. In most countries, the costs of electricity distribution operators are regulated by the government. However, the cost regulation may create adverse incentives to compromise the quality of service. To avoid this, cost regulation is often amended with quality incentives. This study applies theory and methods of productivity analysis to model the frontier of service quality. A semi-nonparametric estimation method is developed, which does not assume any particular functional form for the quality frontier, but can accommodate stochastic noise and heteroscedasticity. The empirical part of our paper examines how underground cabling and location affect the interruption costs. As expected, higher proportion of underground cabling decreases the level of interruption costs. The effects of cabling and location on the variance of performance are also considered. Especially the location is found to be a significant source of heteroscedasticity in the interruption costs. Finally, the proposed quality frontier benchmark is compared to the current practice of Finnish regulation system. The proposed quality frontier is found to provide more meaningful and stable basis for setting quality targets than the average practice benchmarks currently in use.

The 22Ne(α,γ)26Mg and 22Ne(α,n)25Mg reactions play an important role in astrophysics because they have significant influence on the neutron flux during the weak branch of the s-process. We constrain the astrophysical rates for these reactions by measuring partial α-widths of resonances in 26Mg located in the Gamow window for the Ne22+α capture. These resonances were populated using 22Ne(6Li,d)26Mg and 22Ne(7Li,t)26Mg reactions at energies near the Coulomb barrier. At these low energies α-transfer reactions favor population of low spin states and the extracted partial α-widths for the observed resonances exhibit only minor dependence on the model parameters. The astrophysical rates for both the 22Ne(α,γ)26Mg and the 22Ne(α,n)25Mg reactions are shown to be significantly different than the previously suggested values. Keywords: s-Process, Reaction rate, 22Ne(α,γ)26Mg, 22Ne(α,n)25Mg, Sub-Coulomb α-transfer reaction

The spin distribution populated in the $^{150}\mathrm{Sm}(p,t)$ reaction with 25 MeV protons has been investigated using the silicon telescope and high-purity germanium array Hyperion. Angular distributions of outgoing tritons and relative intensities of $\ensuremath{\gamma}$ rays from low-lying levels are used to deduce the initial spin distribution using statistical calculations and are compared with a semiclassical model of the $(p,t)$ reaction. Experimental and theoretical results suggest a peak strength near $4\ensuremath{\hbar}$ when gated on outgoing tritons detected in Hyperion, while the full $4\ensuremath{\pi}$ distribution may peak near $2\ensuremath{\hbar}$. Additionally, the average $\ensuremath{\gamma}$-neutron branching ratio is determined from the data with the aid of one of two new codes presented in this work. The analysis is extended to other recent studies of $^{152,154}\mathrm{Sm}(p,t)$ to form systematics of the spin-dependence of the surrogate method applied to heavy nuclei in the transitional to deformed region.

International audience; The 9C breakup reaction was investigated in order to obtain information about the inverse reaction: 8B(p,γ)9C at astro-physical energies within the NP1412SAMURAI29R1 experiment. The 8B(p,γ)9C reaction gives a possible path to the hot pp chain pp-IV at high temperatures and away from it toward a rapid alpha-process rap-I at high temperatures and densities and therefore is important in understanding nucleosynthesis in super-massive hot stars in the early universe, including possible bypass of the 3α-process. For this experiment it was proposed to use a combination of nuclear and Coulomb dissociation measurements (on a light target Be or C and on a heavy target Pb, respectively) at energy of 160 A MeV to extract structure information, which will allow to evaluate the radiative proton capture cross section at low energies and from there the reaction rate. The current work is focused on the development of Monte Carlo simulations for Coulomb breakup mechanism of 9C as well as on the Geant4 simulations of the resulting particle trajectories through the experimental setup, including passage of the particles through the magnetic field of the SAMURAI spectrometer.

International audience; ONe novae thermonuclear simulations still show uncertainties in the abundance of the final elements. This comes from the uncertainties that are present in some reaction rates that are considered to be important. One of this is the resonant proton capture on 30P. For decades various experiments tried to restrain the large variations in the reaction rates and many improvements have been made, but the results are still inconclusive. Decay spectroscopy This proceeding paper aims to make a comparison between two indirect methods that can be used to reach the reaction rate of the above-mentioned reaction, by briefly describing the procedure and detection methods used.

Obtaining reliable data for nuclear reactions on unstable isotopes remains an extremely important task and a formidable challenge. Neutron capture cross sections---crucial ingredients for models of astrophysical processes, national security applications, and simulations of nuclear energy generation---are particularly elusive, as both projectile and target in the reaction are unstable. We demonstrate a new method for determining cross sections for neutron capture on unstable isotopes, using $^{87}\mathrm{Y}(n,\ensuremath{\gamma})$ as a prototype. To validate the method, a benchmark experiment is carried out to obtain the known $^{90}\mathrm{Zr}(n,\ensuremath{\gamma})$ cross section analogously. Our approach, which employs an indirect (``surrogate'') measurement combined with theory, can be generalized to a larger class of nuclear reactions. It can be used both with traditional stable-beam experiments and in inverse kinematics at rare-isotope facilities.

We have measured the half-life of 30S, the parent of a superallowed 0+-to-0+ beta transition, to high precision using very pure sources and a 4pi proportional gas counter to detect the decay positrons. Our result for the half-life is 1.17992(34) s. As a byproduct of this measurement, we determined the half-life of its daughter, 30P, to be 2.501(2) min., Comment: 9 pages, 7 figures

We study the effects of intergovernmental grants on school spending within the Finnish system of high school education funding. Using a kinked grant rule, the system allocates lump-sum intergovernmental grants to local high school education providers. Utilizing the quasi-experimental variation in grants given by the rule, we identify the effects of the grants on municipal high school education expenditures. Our results indicate that the grants stimulate spending, while local tax rates or revenues do not seem to be responsive to the grants, suggesting the presence of a typical flypaper effect. However, we also consider the possibility that the grant responses might be heterogeneous among municipalities. Based on our heterogeneity results, the grant response is positively associated with the share of the high school age population, and a higher share of elderly persons is related to a lower propensity to spend on education out of grant funding. This result is in line with the idea of intergenerational conflict in education spending preferences presented in education finance literature.

We study the sequential breakup of E/A=24.0 MeV ^{7}Li projectiles excited through inelastic interactions with C, Be, and Al target nuclei. For peripheral events that do not excite the target, we find very large spin alignment of the excited ^{7}Li projectiles longitudinal to the beam axis. This spin alignment is independent of the target used, and we propose a simple alignment mechanism that arises from an angular-momentum-excitation-energy mismatch. This mechanism is independent of the potential used for scattering and should be present in many scattering experiments.

International audience; To study very low-energy β-delayed proton decay, which are of interest for astrophysics, it is essential to achieve an efficient suppression of the β-background. ASTROBOX is such a device: energetic precursor nuclei are produced, identified and then stopped in the gas volume of the detector. The resulting β or β-proton decay traces are ionizing paths in the gas. The electrons produced through ionization are drifted in an electric field and are amplified with a Micro Pattern Gas Amplifier Detector (MPGAD). High gain and high signal to noise ratio are expected to be obtained. The two predecessors of this detection system which is under construction now in our group are AstroBox and AstroBox2, which were built and commissioned at Texas A&M University. The goal of this project is to build and use AstroBox2E at European facilities.

The structure of exotic nucleus 10N was studied using 9C+p resonance scattering. Two L=0 resonances were found to be the lowest states in 10N. The ground state of 10N is unbound with respect to proton decay by 2.2(2) or 1.9(2) MeV depending on the 2- or 1- spin-parity assignment, and the first excited state is unbound by 2.8(2) MeV., 6 pages, 4 figures, 1 table, submitted to Phys. Lett. B

Author(s): Munson, JM; Norman, EB; Burke, JT; Casperson, RJ; Phair, LW; McCleskey, E; McCleskey, M; Lee, D; Hughes, RO; Ota, S; Czeszumska, A; Chodash, PA; Saastamoinen, AJ; Austin, RAE; Spiridon, AE; Dag, M; Chyzh, R; Basunia, MS; Ressler, JJ; Ross, TJ | Abstract: The nuclear reactions C12(C12,α)Ne20, C12(C12,p)Na23, and C12(C12,n)Mg23 are the primary reactions in carbon burning, which occurs as part of several stellar processes. The Gamow window, which describes the energy range where most of these reactions take place, is typically around 1.5 MeV in the center-of-mass frame. Direct measurements of the cross sections at this energy are difficult due to the large Coulomb barrier present between the carbon nuclei; however, a successful surrogate measurement can provide the branching ratios between these reactions while avoiding the C12+C12 Coulomb barrier. An experiment was performed using inelastic scattering of 40 MeV α particles on Mg24 as a possible surrogate for the C12+C12 compound nucleus.

The effect of corruption on economic growth has attracted interest in empirical development economics. The conventional view of corruption as impediment for growth has been challenged by the ‘grease-on-the-wheels’ hypothesis. We take a new perspective on the issue and suggest corruption as macro risk, referred to as a ‘gamble’ hypothesis. Using cross-country data and two alternative indicators of corruption, we find corruption to be a significant driver of heteroscedasticity in total productivity. This supports the new gamble hypothesis. We also note some misleading interpretations in the previously published frontier applications. To avoid these shortcomings, we apply a flexible semi-nonparametric estimator.

Highly enriched 235 U targets were irradiated with 6.5 − 16.1 MeV protons and 20.4 − 42.0 MeV 3 He ions. The irradiated targets were measured with γ and α spectrometric methods to identify and quantify the produced reaction products. After primary activity measurements the targets were dissolved, and interesting Pu and Np reaction products were chemically separated from the target material, and measured for activity again. From the activity results it was possible to calculate the reaction cross sections for differently produced nuclides. The data obtained from the experiment resulted in earlier unknown excitation functions on proton and 3 He induced nuclear reactions on 235 U.

A new accurate determination of beta-delayed neutron emission probabilities from nuclei in the low mass region of the light fission group has been performed. The measurements were carried out using the BELEN 4π neutron counter at the IGISOL-JYFL mass separator in combination with a Penning trap. The new results significantly improve the uncertainties of neutron emission probabilities for {sup 91}Br, {sup 86}As, {sup 85}As, and {sup 85}Ge nuclei.

New levels and $\ensuremath{\gamma}$-ray transitions were identified in $^{150,152}\mathrm{Sm}$ utilizing the $(p,t)$ reaction and particle-$\ensuremath{\gamma}$ coincidence data. A large, peak-like structure observed between 2.3--3.0 MeV in excitation energy in the triton energy spectra was also investigated. The orbital angular-momentum transfer was probed by comparing the experimental angular distributions of the outgoing tritons to calculated distorted wave Born approximation curves. The angular distributions of the outgoing tritons populating the peak-like structure are remarkably similar in the two reactions and are significantly different from the angular distributions associated with the nearby continuum region. Relative partial cross sections for the observed levels, angle averaged between 34 and 58 degrees, were measured. In $^{150}\mathrm{Sm}$, 39(4)% of the strength of the peak-like structure could be accounted for by the observed discrete states. This compares with a value of 93(15)% for $^{152}\mathrm{Sm}$.

In the past several years, there has been a large interest of Time Projection Chambers (TPCs) for use in experimental nuclear physics. This has continued in tandem with the requirement for high efficiency detectors with low intensity radioactive ion beams. TexAT is a Active Target TPC (AT-TPC) built at Texas A&M University utilizing MICRO MEsh GASeous (MicroMegas) pads and GET electronics developed specifically for TPCs. This design combines good TPC pixelation with a surrounding shell of Si/CsI telescopes to make an extremely versatile detector capable of a wide range of different experimental techniques with only minor modifications to the electronics setup. Two recent experiments performed at the Cyclotron Institute, Texas A&M University, are detailed here demonstrating versatility beyond the usual Thick Target Inverse Kinematics (TTIK) or transfer reactions that these TPCs are more typically used for. The first, a measurement of the 12N → 12C* → 3α decay demonstrates the capabilities of TexAT as a low-energy detector operating at low pressure (20 Torr) to measure β-delayed particle decay. The second, a direct measurement of the 8B+40Ar fusion cross section shows the advantages of operating in active target mode where the target also functions as the detector gas.

Two veins of literature, namely, production risk literature and stochastic frontier analysis, are examined. Both fields are concerned of output variation; the former due to exogenous shocks, the latter due inefficiency. By covering the literature from both the fields, this review suggests that the concept of heteroscedasticity can be utilized to build a synthesis between these mainly separate branches of literature. However, the synthetic approach brings a challenge how to differentiate between different sources of output variation. This challenge is identified as the main obstacle to meaningfully combine the two approaches.

A new method for determining independent fission products is used in an experiment at the Accelerator Laboratory of the University of Jyvaskyla. The method combines the chemical universality of the ion guide technique and the unique properties of the Penning trap. A beam of charged particles is formed by stopping fission products in gaseous helium. The Penning trap is employed as a highly accurate filter to identify particles by their mass. The yields of fission products are determined by the ion count downstream of the trap. The setup’s mass resolving power is on the order of 105 with a radio frequency excitation time of 400 ms. Such high mass resolution occasionally allows us not only to separate nuclides but to separate the isomeric and ground states of nuclei as well. Independent yields of fission products are measured in the fission reaction of the 232Th isotope by protons with an energy of 25 MeV. A short description of the method ae nd soexperimental data are supplememnted by the results fro theoretical calculations.

Electricity distribution is a natural local monopoly. In many countries, the regulators of this sector apply frontier methods such as data envelopment analysis (DEA) or stochastic frontier analysis (SFA) to estimate the efficient cost of operation. In Finland, a new StoNED method was adopted in 2012. This paper compares DEA, SFA and StoNED in the context of regulating electricity distribution. Using data from Finland, we compare the impacts of methodological choices on cost efficiency estimates and acceptable cost. While the efficiency estimates are highly correlated, the cost targets reveal major differences. In addition, we examine performance of the methods by Monte Carlo simulations. We calibrate the data generation process (DGP) to closely match the empirical data and the model specification of the regulator. We find that the StoNED estimator yields a root mean squared error (RMSE) of 4% with the sample size 100. Precision improves as the sample size increases. The DEA estimator yields an RMSE of approximately 10%, but performance deteriorates as the sample size increases. The SFA estimator has an RMSE of 144%. The poor performance of SFA is due to the wrong functional form and multicollinearity.

An instrument, AstroBox, has been developed to perform low energy proton spectroscopy from β-delayed proton emitters of interest to astrophysics studies. Energetic precursor nuclei are identified and stopped in the gas volume of the detector. The subsequent β or β-proton decay traces ionized paths in the gas. The ionization electrons are drifted in an electric field and are amplified with a Micro Pattern Gas Amplifier Detector (MPGAD). The system was tested in-beam using the β-delayed proton-emitter 23Al, which was produced with the p(24Mg,23Al)2n reaction and separated with the Momentum Achromat Recoil Spectrometer (MARS) at the Cyclotron Institute at Texas A&M University. Off-beam proton spectra have essentially no β background down to ∼ 100 keV and have a resolution of ∼ 15 keV (fwhm) for proton-decay lines at E p = 197 and 255 keV. Lines with βp-branching as low as 0.02% are observed. In addition, the device also gives good mass and charge resolution for energetic heavy ions measured in-beam.