Rotational excitation of the Hoyle state in 12C

12C is synthesised in stars by fusion of three α particles. This process occurs through a resonance in the 12C nucleus, famously known as the Hoyle state. In this state, the 12C nucleus exists as a cluster of α particles. The state is the band-head for a rotational band with the 2+ rotational excitation predicted in the energy region 9 - 11 MeV. This rotational excitation can affect the triple-α process reaction rate by more than an order of magnitude at high temperatures (109 K). Depending on the energy of the resonance, the knowledge of the state can also help determine the structure of the Hoyle state. In the work presented here, the state of interest is populated by beta decay of radioactive 12N ion beam delivered by the IGISOL facility at JYFL, Jyväskylä

Branching ratios in the β decays of N12 and B12

Absolute branching ratios to unbound states in C12 populated in the β decays of N12 and B12 are reported. Clean sources of N12 and B12 were obtained using the isotope separation on-line (ISOL) method. The relative branching ratios to the different populated states were extracted using single-alpha as well as complete kinematics triple-alpha spectra. These two largely independent methods give consistent results. Absolute normalization is achieved via the precisely known absolute branching ratio to the bound 4.44 MeV state in C12. The extracted branching ratios to the unbound states are a factor of three more precise than previous measurements. Branching ratios in the decay of Na20 are also extracted and used to check the results. © 2009 The American Physical Society.Supported by the Academy of Finland (Project No. 44875), by the Spanish Agency CICYT (Nos. FPA2007–62170 and FPA2007–62216), by the European Union Sixth Framework Programme “EURONS” (No. 506065), by the Swedish Research Council, and the Knut and Alice Wallenberg foundation.Peer Reviewe

The science case of the FRS Ion Catcher for FAIR Phase-0

The FRS Ion Catcher at GSI enables precision experiments with thermalized projectile and fission fragments. At the same time it serves as a test facility for the Low-Energy Branch of the Super-FRS at FAIR. The FRS Ion Catcher has been commissioned and its performance has been characterized in five experiments with 238U and 124Xe projectile and fission fragments produced at energies in the range from 300 to 1000 MeV/u. High and almost element-independent efficiencies for the thermalization of short-lived nuclides produced at relativistic energies have been obtained. High-accuracy mass measurements of more than 30 projectile and fission fragments have been performed with a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) at mass resolving powers of up to 410,000, with production cross sections down to the microbarn-level, and at rates down to a few ions per hour. The versatility of the MR-TOF-MS for isomer research has been demonstrated by the measurement of various isomers, determination of excitation energies and the production of a pure isomeric beam. Recently, several instrumental upgrades have been implemented at the FRS Ion Catcher. New experiments will be carried out during FAIR Phase-0 at GSI, including direct mass measurements of neutron-deficient nuclides below 100Sn and neutron-rich nuclides below 208Pb, measurement of β-delayed neutron emission probabilities and reaction studies with multi-nucleon transfer.Peer reviewe

Conversion electron spectroscopy at IGISOL

Conversion elecron spectroscopy has been an important part of the nuclear spectrocopy research at the Department of Physics of the University of Jyv¨askyl¨a since the commissioning of the first cyclotron in the mid 1970s. At the IGISOL facility a specialiced conversion electron spectrometer ELLI was developed in the late 1980s. The first results with ELLI were obtained using the beams from the old MC-20 cyclotron to study newly discovered isotopes of refractory fission products. In the present K130 cyclotron laboratory ELLI has been utilized in many decay-spectroscopy experiments both neutron-deficient and neutron-rich side of the valley of stability. In the early 2000s the new JYFLTRAP ion trap system overthrew ELLI from its permanent place in the IGISOL beamline. Conversion electron spectroscopy has continued with the new Penning trap that has been used in in-trap electron spectroscopy tests and post-trap electron spectroscopy is foreseen.peerReviewe

Does goal orientation relate to changes in sports club participation from adolescence to early adulthood?

Background Sports club participation begins to decrease in adolescence. There is a lack of knowledge, how sports club participation changes from adolescence to early adulthood in Finland, and how goal orientation influences on it. Therefore, the aim of this study is to examine if goal orientation is associated to changes in sports club participation during afore mentioned critical years. Methods The study design is longitudinal. A sample of 366 (140 boys, 226 girls) adolescents were followed from age 15 (year 2014) to age 19 (year 2018). Sports club participation (yes/no) and goal orientation (no competitive goal, sports for hobby or physical development/regional, national or international success in adolescence/national, international or professional success in adulthood) were measured using questionnaires. In order to study changes in sports club participation, and goal orientation, descriptive statistics were performed. Gender differences were estimated using Chi-squared tests. A binary logistic regression analysis was carried out to examine the association between sports club participation, goal orientation and gender. Results By the age 19, 33% of boys and 43% of girls had dropped out from sports club, 45% of boys and 26% of girls had continued participation, and 21% of boys and 31% of girls never participated (p > 0.01). More boys (57%) than girls (31%) had a success in adulthood as a goal, and more girls (48%) than boys (27%) had a success in adolescence as a goal (p > 0.001). Adolescents with success in adulthood as a goal continued participation in sports club more likely than adolescents without competitive goal (OR = 4.81; 95% CI 2.26-10.23). Furthermore, boys were more likely to continue participation than girls (OR = 1.75; 95% CI 1.02-3.01). Conclusions The dropout from sports club activities from adolescence to early adulthood is obvious. Especially the adolescents without a competitive goal and girls are in danger to drop out. This indicates that contemporary forms of sports club activities support adolescents with strong competitive orientation. Therefore, there is a need for sports clubs to develop activities suitable for adolescents with less competitive orientation to ensure their continuous participation in sports club.nonPeerReviewe

Status of the ion trap project at IGISOL

The IGISOL fa ility at the Department of Physi s of the University of Jyväskylä (JYFL) is delivering radioa tive beams of short-lived exoti nu lei, in parti ular the neutron-ri h isotopes from the ssion rea tion. These nu lei are studied with the nu lear spe tros opy methods. In order to substantially in rease the quality and sensitivity of su h studies the beam should undergo beam handling: ooling, bun hing and isobari puri ation. The rst two pro esses are performed with the use of an RFQ ooler/bun her. The isobari puri ation will be made by a Penning trap pla ed after the RF- ooler element. This ontribution des ribes the urrent status of the ion trap pro je t and its future prospe ts. The latter omprise the pre ise nu lear mass measurements, nu lear spe tros opy in the Penning trap interior as well as the laser spe tros opy on the extra ted beams.peerReviewe

High-precision mass measurements for the rp-process at JYFLTRAP

The double Penning trap JYFLTRAP at the University of Jyvaskyla has been successfully used to achieve high-precision mass measurements of nuclei involved in the rapid proton-capture (rp) process. A precise mass measurement of 31Cl is essential to estimate the waiting point condition of 30S in the rp-process occurring in type I x-ray bursts (XRBs). The mass-excess of 31Cl measured at JYFLTRAP, -7034.7(3.4) keV, is 15 more precise than the value given in the Atomic Mass Evaluation 2012. The proton separation energy Sp determined from the new mass-excess value confirmed that 30S is a waiting point, with a lowertemperature limit of 0.44 GK. The mass of 52Co effects both 51Fe(p,γ)52Co and 52Co(p,γ)53Ni reactions. The mass-excess value measured, - 34 331.6(6.6) keV is 30 times more precise than the value given in AME2012. The Q values for the 51Fe(p,γ)52Co and 52Co(p,γ)53Ni reactions are now known with a high precision, 1418(11) keV and 2588(26) keV respectively. The results show that 52Co is more proton bound and 53Ni less proton bound than what was expected from the extrapolated value.peerReviewe

High-precision mass measurements for the rp-process at JYFLTRAP

The double Penning trap JYFLTRAP at the University of Jyväskylä has been successfully used to achieve high-precision mass measurements of nuclei involved in the rapid proton-capture (rp) process. A precise mass measurement of 31Cl is essential to estimate the waiting point condition of 30S in the rp-process occurring in type I x-ray bursts (XRBs). The mass-excess of 31C1 measured at JYFLTRAP, -7034.7(3.4) keV, is 15 more precise than the value given in the Atomic Mass Evaluation 2012. The proton separation energy Sp determined from the new mass-excess value confirmed that 30S is a waiting point, with a lower-temperature limit of 0.44 GK. The mass of 52Co effects both 51Fe(p,γ)52Co and 52Co(p,γ)53Ni reactions. The mass-excess value measured, - 34 331.6(6.6) keV is 30 times more precise than the value given in AME2012. The Q values for the 51Fe(p,γ)52Co and 52Co(p,γ)53Ni reactions are now known with a high precision, 1418(11) keV and 2588(26) keV respectively. The results show that 52Co is more proton bound and 53Ni less proton bound than what was expected from the extrapolated value

A facility for production and laser cooling of cesium isotopes and isomers

We report on the design, installation, and test of an experimental facility for the production of ultra-cold atomic isotopes and isomers of cesium. The setup covers a broad span of mass numbers and nuclear isomers, allowing one to directly compare chains of isotopes and isotope/isomer pairs. Cesium nuclei are produced by fission or fusion-evaporation reactions using primary proton beams from a 130 MeV cyclotron impinging upon a suitable target. The species of interest is ejected from the target in ionic form, electrostatically accelerated, mass separated, and routed to a science chamber. Here, ions are neutralized by implantation in a thin foil, and extracted by thermal diffusion. A neutral vapor at room temperature is thus formed and trapped in a magneto-optical trap. Real-time fluorescence imaging and destructive absorption imaging provide information on the number of trapped atoms, their density, and their temperature. Tests with a dedicated beam of 133Cs ions at 30 KeV energy confirm neutralization, evaporation, and laser cooling to 150 K, with an average atomic density of 1010 cm−3. Availability of cold and dense atomic samples of Cs isotopes and isomers opens new avenues for high-precision measurements of isotopic and isomeric shifts thereby gaining deeper insight into the nuclear structure, as well as for sensitive measurements of isotopes’ concentration ratios in trace quantities. The facility also constitutes the core for future experiments of many-body physics with nuclear isomers.peerReviewe