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1. Sulphur dioxide and sulphuric acid concentrations in the vicinity of Kilpilahti industrial area

Author

Henrik Westerholm, Markku Kulmala, Tuija Jokinen, Heikki Junninen, Johanna Patokoski, Jukka Teittinen, Katrianne Lehtipalo, Siegfried Schobesbergera, Mikko Sipilä, Maija Kajos, Risto Taipale, Kai Larnimaa, Tuukka Petäjä, Jani Hakala, and Nina Sarnela

Subjects
inorganic chemicals, Industrial area, digestive, oral, and skin physiology, Oil refinery, Environmental engineering, chemistry.chemical_element, Sulphur compound, on-line measurements, Sulfur, Measurement site, respiratory tract diseases, chemistry, aerosol concentrations, Air mass, industrial emissions
Abstract

Industrial activity is a major source of sulphur compound emissions. The sulphuric acid and sulphur dioxide measurements in the vicinity of the industrial area and the oil refinery in Kilpilahti expressed great variation in concentration. The hourly mean values of concentration were categorized according to the area from where the air mass was travelling towards the measurement site. The statistical characteristics and diurnal behavior of emissions between these areas were significantly different.

Published
2013
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2. The particle size magnifier closing the gap between measurement of molecules, molecular clusters and aerosol particles

Author

Douglas R. Worsnop, Markku Kulmala, Heikki Junninen, Juha Kangasluoma, Katrianne Lehtipalo, Jyri Mikkilä, Mikko Sipilä, Tuukka Petäjä, Alessandro Franchin, Tuija Jokinen, Siegfried Schobesberger, and Nina Sarnela

Subjects
Supersaturation, Free particle, Chemical physics, Chemistry, Analytical chemistry, Particle, Nanoparticle, Molecule, Particle size, Condensation particle counter, Aerosol
Abstract

The Particle Size Magnifier lowers the cut-off size of a Condensation Particle Counter even down to about 1 nm in mobility diameter. By scanning the supersaturation also size information of the particles can be gained. We demonstrated that the PSM can detect particles starting from molecular sizes. By combining the data with newly developed mass spectrometric methods particle formation and growth can be followed molecule by molecule.

Published
2013
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3. Measurement of neutral sulfuric acid-dimethylamine clusters using CI-APi-TOF-MS

Author

Mario Simon, Andreas Kürten, Tuija Jokinen, Nina Sarnela, Mikko Sipilä, Linda Rondo, Sebastian Ehrhart, Heikki Junninen, Manuel Hutterli, Jasper Kirkby, Douglas R. Worsnop, Joachim Curtius, null CLOUD Collaboration, DeMott, P. J., and ODowd, C. D.

Subjects
chemistry.chemical_compound, Ternary numeral system, chemistry, Inorganic chemistry, Nucleation, Particle, Sulfuric acid, Time-of-flight mass spectrometry, Ternary operation, Dimethylamine, Aerosol
Abstract

Recent studies suggest that dimethylamine could be a key ternary species in the formation and early growth of atmospheric aerosol particles. We report on nucleation studies for the ternary system of sulfuric acid, water and dimethylamine which have been performed at the CERN CLOUD chamber. These studies were conducted at atmospherically relevant concentrations of sulfuric acid and dimethylamine at 278 K and 38% RH. Two newly developed Chemical Ionization-Atmospheric Pressure interface-Time of Flight-Mass Spectrometers (CIAPi-TOF-MS) were used to measure the time-resolved concentration of neutral clusters containing sulfuric acid and dimethylamine. Results from other instrumental techniques are included in the analysis as well to obtain a deeper insight into the occurring mechanisms. It is the first time that the neutral nucleation pathway has been studied in such detail from the early generation of sulfuric acid monomers up to particle sizes reaching several nanometers.

Published
2013
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4. Nucleation of H[sub 2]SO[sub 4] and oxidized organics in CLOUD experiment

Author

Mikko Sipilä, Nina Sarnela, Tuija Jokinen, Tuomo Nieminen, Joao Almeida, Jasmin Tröstl, Katrianne Lehtipalo, Jonathan Duplissy, Heikki Junninen, and null CLOUD Collaboration

Subjects
chemistry.chemical_compound, CLOUD experiment, Chemistry, law, Chemical physics, Environmental chemistry, Atmospheric chemistry, Nucleation, Particle, Sulfuric acid, Cosmic ray, Cloud chamber, law.invention
Abstract

The research of atmospheric new particle formation has proceeded lately as the role of sulphuric acid has been established. Still, the roles of other atmospheric compounds in nucleation remain largely unclear. To clarify the first steps of atmospheric new particle formation extensive nucleation experiments were performed in CLOUD chamber in 2012. Especially the role of oxidations products of α-pinene was studied in detail. The experiments provided new information about the part of oxidized organics in nucleation.

Published
2013
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5. Aerosol nucleation and growth in a mixture of sulfuric acid/alpha-pinene oxidation products at the CERN CLOUD chamber

Author

Jasmin Tröstl, Federico Bianchi, Andreas Kürten, Linda Rondo, Mario Simon, Nina Sarnela, Tuija Jokinen, Martin Heinritzi, Josef Dommen, Jasper Kirkby, Ernest Weingartner, Urs Baltensperger, null CLOUD Collaboration, DeMott, Paul J., and O'Dowd, Colin D.

Subjects
Ozone, Chemistry, Condensation, Nucleation, Sulfuric acid, Atmospheric sciences, law.invention, Aerosol, chemistry.chemical_compound, Chemical engineering, law, Scanning mobility particle sizer, Particle, Cloud chamber
Abstract

The role of α-pinene in aerosol nucleation and growth was investigated using the CERN CLOUD chamber, a nano scanning mobility particle sizer (nanoSMPS) and several condensation particle counters (CPCs) with different diameter cut-offs. Different oxidation conditions for α-pinene - OH⋅ vs. ozone oxidation - were considered to investigate their contributions to particle nucleation and growth. Results from the latest CERN experiment from fall 2012 (CLOUD 7) are presented.

Published
2013
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6. Total absorption γ-ray spectroscopy of beta delayed neutron emitters

Author

Ari Jokinen, P. H. Regan, Igisol People, J. Agramunt, Tommi Eronen, Stephen Rice, T. Martinez, M. B. Gómez-Hornillos, Christine Weber, V. M. Bui, Heikki Penttilä, J. L. Tain, D. Cano-Ott, E. Estevez, E. Mendoza, A. R. García, V. Eloma, Juho Rissanen, Jani Hakala, M. Fallot, Alejandro Algora, Juha Äystö, R. Caballero-Folch, V. Gorlychev, Iain Moore, F. G. Kondev, Anu Kankainen, W. Gelletly, A. Porta, B. Rubio, M. Bowry, A. Perez, E. Valencia, A.-A. Zakari-Issoufou, F. Molina, M. D. Jordan, G. F. Farrelly, and Zs. Podolyák

Subjects
Physics, Nuclear physics, Decay scheme, Double beta decay, Beta particle, Neutron, Decay heat, Delayed neutron, Beta-decay stable isobars, Radioactive decay
Abstract

Preliminary results of the data analysis of the beta decay of 94Rb using a novel - segmented- total absorption spectrometer are shown in this contribution. This result is part of a systematic study of important contributors to the decay heat problem in nuclear reactors. In this particular case the goal is to determine the beta intensity distribution below the neutron separation energy and the gamma/beta competition above.

Published
2013
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7. Study of excited states of [sup 31]S through beta-decay of [sup 31]Cl for nucleosynthesis in ONe novae

Author

P. J. Woods, Antti Saastamoinen, T. Davinson, J. C. Hardy, E. Simmons, Ari Jokinen, M. McCleskey, Juha Äystö, G. Tabacaru, L. Trache, M. A. Bentley, A. Banu, V. E. Iacob, Brian Roeder, and R. E. Tribble

Subjects
Nuclear physics, Physics, Decay scheme, Mass excess, ta114, Nucleosynthesis, Excited state, Isobar, Resonance, Atomic physics, Ground state, Beta decay
Abstract

We have produced an intense and pure beam of 31Cl with the MARS Separator at the Texas A&M University and studied β‐decay of 31Cl by implanting the beam into a novel detector setup, capable of measuring β‐delayed protons and γ‐rays simultaneously. From our data, we have established decay scheme of 31Cl, found resonance energies with 1 keV precision, have measured its half‐life with under 1% accuracy, found its Isobar Analog State decay and by using the IMME obtained an improved mass excess for its ground state. In this contribution, a description of the used method along with selected preliminary experimental results are given and their relevance for novae nucleosynthesis discussed.

Published
2011
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8. TAS measurements for reactor physics and nuclear structure

Author

A. Algora, D. Jordan, J. L. Taín, B. Rubio, J. Agramunt, L. Caballero, E. Nácher, A. B. Perez-Cerdan, F. Molina, E. Estevez, A. Krasznahorkay, M. D. Hunyadi, J. Gulyás, A. Vitéz, M. Csatlós, L. Csige, J. Äysto, H. Penttilä, S. Rinta-Antila, I. Moore, T. Eronen, A. Jokinen, A. Nieminen, J. Hakala, P. Karvonen, A. Kankainen, U. Hager, T. Sonoda, A. Saastamoinen, J. Rissanen, T. Kessler, C. Weber, J. Ronkainen, S. Rahaman, V. Elomaa, K. Burkard, W. Hüller, L. Batist, W. Gelletly, A. L. Nichols, T. Yoshida, A. A. Sonzogni, K. Peräjärvi, Paraskevi Demetriou, Rauno Julin, and Sotirios Harissopulos

Subjects
Physics, Nuclear physics, Nuclear reaction, Nuclear Theory, Nuclear structure, Neutron, Decay heat, Nuclear Experiment, Nucleon, Absorption (electromagnetic radiation), Penning trap, Radioactive decay
Abstract

In this contribution we will present recent total absorption measurements of the beta decay of neutron‐rich nuclei performed at the IGISOL facility of the Univ. of Jyvaskyla. In the measurements the JYFL Penning Trap was used as a high resolution isobaric separator. The total absorption technique will be described and the impact of recent results in the fields of reactor physics (decay heat calculations) and nuclear structure will be discussed.

Published
2011
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9. Astrophysical Reaction Rates Obtained By Indirect Techniques

Author

R. E. Tribble, T. Al-Abdullah, A. Alharbi, J. Äystö, A. Banu, V. Burjan, F. Carstoiu, X. Chen, H. L. Clark, T. Davidson, C. Fu, C. A. Gagliardi, J. C. Hardy, V. E. Iacob, J. Jokinen, V. Kroha, Y.-W. Lui, M. McCleskey, A. Mukhamedzhanov, N. Nica, H. I. Park, B. Roeder, A. Saastamoinen, E. Simmons, G. Tabacaru, Y. Tokimoto, L. Trache, P. J. Woods, Y. Zhai, Isao Tanihara, Hooi Jin Ong, Atsushi Tamii, Tadafumi Kishimoto, Toshitaka Kajino, Shigeru Kubono, and Tatsushi Shima

Subjects
Nuclear physics, Nuclear reaction, Physics, Reaction rate, Proton, Nucleon
Abstract

Indirect techniques have been used to obtain information about reaction rates for several proton capture reactions that occur on short‐lived nuclei. The techniques used to carry out the measurements are reviewed and the results obtained are presented. Also future prospects for further measurements with a new facility, T‐REX are discussed.

Published
2010
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10. β-decay of [sup 23]Al and nova nucleosynthesis

Author

A. Saastamoinen, L. Trache, A. Banu, M. A. Bentley, T. Davinson, J. C. Hardy, V. E. Iacob, D. G. Jenkins, A. Jokinen, M. McCleskey, B. Roeder, E. Simmons, G. Tabacaru, R. E. Tribble, P. J. Woods, J. Äystö, Livius Trache, Alexei Smirnov, and Sabin Stoica

Subjects
Physics, Nuclear physics, Proton, Nucleosynthesis, Branching fraction, Double beta decay, Hadron, Gamma ray, High Energy Physics::Experiment, Astrophysics, Nucleon, Radioactive decay
Abstract

We have studied the β‐decay of 23Al with a novel detector setup at the focal plane of the MARS separator at the Texas A&M University to resolve existing controversies about the proton intensities of the IAS in 23Mg and to determine the absolute proton branching ratios by combining our results to the latest γ‐decay data. Experimental technique, results and the relevance for nova nucleosynthesis are discussed.

Published
2010
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11. Selected properties of nuclei at the magic shell closures from the studies of E1, M1 and E2 transition rates

Author

H. Mach, A.-M. Baluyut, D. Smith, E. Ruchowska, U. Köster, L. M. Fraile, H. Penttilä, J. Äystö, R. Boutami, H. Bradley, N. Braun, V.-V. Elomaa, T. Eronen, C. Fransen, D. G. Ghiţă, J. Hakala, M. Hauth, A. Jokinen, J. Jolie, P. Karvonen, T. Kessler, W. Kurcewicz, H. Lehmann, I. D. Moore, J. Nyberg, S. Rahaman, J. Rissanen, J. Ronkainen, P. Ronkanen, A. Saastamoinen, T. Sonoda, O. Steczkiewicz, V. Ugryumov, C. Weber, Jan Jolie, Andreas Zilges, Nigel Warr, and Andrey Blazhev

Subjects
Physics, Nuclear Theory, Parity (physics), Nuclear physics, medicine.anatomical_structure, Closure (computer programming), medicine, Neutron, Atomic physics, Nuclear Experiment, Glass transition, Multiplet, Nucleus, Excitation, Radioactive decay
Abstract

Using the Advanced Time‐Delayed method we have studied transition rates in several neutron‐rich nuclei at the magic shell closures. These include the heavy Co and Fe nuclei just below the Z = 28 shell closure at the point of transition from spherical to collective structures. Of particular interest is 63Fe located exactly at the point of transition at N = 37. A substantial increase in the information on this nucleus was obtained from a brief fast timing study conducted at ISOLDE. The new results indicate that 63Fe seems to depart from a simple shell model structure observed for heavier N = 37 isotones of 65Ni and 67Zn.Another region of interest are the heavy Cd and Sn nuclei at N = 72, 74 and the properties of negative parity quasi‐particle excitations. These experiments, performed at the IGISOL separator at Jyvaskyla, revealed interesting properties of the E2 rates in the sequence of E2 transitions connecting the 10+, 8+, 6+, 4+, 2+ and 0+ members of the multiplet of levels in 122Sn due to neutrons in th...

Published
2009
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12. Applications of the total absorption technique to improve reactor decay heat calculations: study of the beta decay of [sup 102,104,105]Tc

Author

A. Algora, D. Jordan, J. L. Taín, B. Rubio, J. Agramunt, A. B. Perez-Cerdan, F. Molina, L. Caballero, E. Nácher, A. Krasznahorkay, M. D. Hunyadi, J. Gulyás, A. Vitéz, M. Csatlós, L. Csige, J. Äystö, H. Penttilä, I. D. Moore, T. Eronen, A. Jokinen, A. Nieminen, J. Hakala, P. Karvonen, A. Kankainen, A. Saastamoinen, J. Rissanen, T. Kessler, C. Weber, J. Ronkainen, S. Rahaman, V. Elomaa, U. Hager, S. Rinta-Antila, T. Sonoda, K. Burkard, W. Hüller, L. Batist, W. Gelletly, T. Yoshida, A. L. Nichols, A. Sonzogni, K. Peräjärvi, Jan Jolie, Andreas Zilges, Nigel Warr, and Andrey Blazhev

Subjects
Nuclear physics, Fission products, Isotope, Decay energy, Chemistry, Double beta decay, Nuclide, Decay heat, Exponential decay, Nuclear Experiment, Beta decay
Abstract

The decay heat of the fission products plays an important role in predicting the heat‐up of nuclear fuel after reactor shutdown. This form of energy release is calculated as the sum of the energy‐weighted activities of all fission products P(t) = ΣEiλiNi(t), where Ei is the decay energy of nuclide i (gamma and beta component), λi is the decay constant of nuclide i and Ni(t) is the number of nuclide i at cooling time t. Even though the reproduction of the measured decay heat has improved in recent years, there is still a long standing discrepancy at t∼1000 s cooling time for some fuels. A possible explanation for this disagreement can been found in the work of Yoshida et al. [1], who demonstrated that an incomplete knowledge of the β‐decay of some Tc isotopes could be the source of the systematic discrepancy. Motivated by [1], we have recently measured the β‐decay process of some Tc isotopes using a total absorption spectrometer at the IGISOL facility in Jyvaskyla. The results of the measurements are discussed, along with their impact on summation calculations.

Published
2009
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13. Mass measurements and proton binding energies near the Z = N line below [sup 100]Sn

Author

Ari Jokinen, Lídia S. Ferreira, and Paramasivan Arumugan

Subjects
Condensed Matter::Quantum Gases, Physics, Proton binding, Binding energy, Nuclear structure, Weak interaction, Penning trap, Atomic mass, Nuclear physics, Nuclear astrophysics, Nuclear binding energy, Physics::Atomic Physics, Atomic physics, Nuclear Experiment
Abstract

Ion traps have been applied widely for measurements of atomic masses with unprecedented precision. JYFLTRAP tandem Penning trap, located in the Department of Physics, University of Jyvaskyla, has provided a vast amount of new data in the vicinity of the N = Z line contributing to nuclear astrophysics, nuclear structure studies, and fundamental questions of weak interaction.

Published
2007
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14. A Systematic Study of β− Decay of Neutron-Rich Rh and Ag Isotopes

Author

J. C. Wang, J. Huikari, S. Nummela, J. Äysto, K. Perjärvi, P.G. Dendooven, J. Szerypo, S. Rinta-Antila, A. Nieminen, V. S. Kolhinen, Y. Wang, A. Jokinen, G. Lhersonnaeu, and H. Penttilä

Subjects
Nuclear physics, Decay scheme, Isotope, Proton, Fission, Chemistry, Gamma spectroscopy, Neutron, Nuclear Experiment, Spectroscopy, Beta decay
Abstract

Beta decay of neutron‐rich even‐mass 114–118Rh and 116–120Ag isotopes has been studied using on‐line mass‐separated sources that were produced by applying 25 MeV proton induced symmetric fission of natural uranium at the IGISOL facility. The β‐γ and γ‐γ coincidence spectroscopy is employed in all cases that enables for the construction of the decay scheme and for the deduction of the decay properties. Systematics for two‐quasineutron states in 114,116,118Pd and for three‐phonon multiplet in 114,116,118Cd are presented and discussed.

Published
2006
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15. Nuclear structure effects probed by precision atomic mass measurements

Author

Ari Jokinen, Tetsu Sonoda, U. Hager, Juha Äystö, V.-V. Elomaa, T. Eronen, Saidur Rahaman, Sami Rinta-Antila, Jani Hakala, Iain Moore, and Anu Kankainen

Subjects
Condensed Matter::Quantum Gases, Physics::Plasma Physics, Chemistry, Nuclear structure, Physics::Accelerator Physics, Physics::Atomic Physics, Trapping, Atomic physics, Nuclear Experiment, Mass spectrometry, Atomic mass, Ion
Abstract

The manipulation of ion beams by trapping techniques at the IGISOL facility is described. Examples of applications of ion traps in spectroscopic studies and mass spectrometry are given.

Published
2006
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16. Spectroscopic studies of neutron-deficient light nuclei: decay properties of 21Mg, 25Si and 26P

Author

J. Honkanen, Peter Dendooven, J. Giovinazzo, S. Czajkowski, Ari Jokinen, J. C. Thomas, M. Lewitowicz, Juha Äystö, B. Blank, A. Ensallem, F. de Oliveira Santos, L. Achouri, C. Longour, R. Béraud, M. Stanoiu, G. Canchel, A.M. Laird, N. Guillet, Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Maglione E., Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
23.50.+z, 23.40.-s, 23.20.Lv, 27.30.+t, Physics, Decay scheme, Proton, Isotopes of germanium, Branching fraction, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, Nuclear physics, Double beta decay, Neutron, Proton emission, Atomic physics, Nuclear Experiment, Radioactive decay
Abstract

Neutron‐deficient nuclei with Tz equals to −3/2 and −2 have been produced at the GANIL/LISE3 facility in fragmentation reactions of a 95 MeV/u 36Ar primary beam in a 12C target. For the first time, β‐delayed proton and β‐γ emission has been simultaneously observed in the decay of 21Mg, 25Si and 26P. The decay scheme of the latter is proposed and the Gamow‐Teller strength distribution in its β decay is compared to shell‐model calculations based on the USD interaction. The B(GT) values derived from the absolute measurement of the β‐branching ratios are in agreement with the quenching factor of about 60% obtained for allowed Gamow‐Teller transitions in this mass region. A precise half‐life of 43.7 (6) ms was determined for 26P, the β‐2p emission of which was studied. The expected contribution of spectroscopic studies of neutron‐rich nuclei is discussed with respect to the mirror asymmetry phenomenon occuring in analogous β decays.

Published
2003
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17. β-delayed p and γ decay of 58Zn and comparison with 58Ni(3He,t)58Cu reaction

Author

A. Jokinen

Subjects
Nuclear physics, Physics, Decay scheme, Internal conversion, Double beta decay, Beta particle, Alpha decay, Positron emission, Atomic physics, Nuclear Experiment, Radioactive decay, Beta-decay stable isobars
Abstract

Symmetry tests between (p,n) type charge‐exchange reactions and beta decay are discussed. An example of such comparison in A=58 system is given with special emphasis to test reliability of charge‐ exchange data as a probe for Gamow‐Teller strength. Data collected so far is reviewed and the recent beta decay experiment at ISOLDE‐CERN is outlined.

Published
2003
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18. Beta-delayed multi-particle emission in proton rich nuclei

Author

Markku Oinonen, Thomas Nilsson, R. Boutami, H. O. U. Fynbo, Björn Jonson, Olof Tengblad, I. G. Mukha, Leif Axelsson, K. Riisager, A. Honkanen, K. Wilhelmsen Rolander, Karin Markenroth, U. C. Bergmann, Juha Äystö, P. Hornshøj, L. M. Fraile, Yolanda Prezado, Gunnar Nyman, P. Deendoven, Jussi Huikari, Ari Jokinen, M. J. G. Borge, and Ismael Martel

Subjects
Nuclear physics, Physics, Decay scheme, Decay energy, Branching fraction, Double beta decay, Alpha decay, Positron emission, Proton emission, Atomic physics, Radioactive decay
Abstract

In this contribution examples of the application of new technologies to disentangle the mechanism of beta-delayed multi-particle emission are given. In particular the mechanism of β-delayed two-proton emission from 31Ar is resolved and proved to be sequential, both for isospin allowed and isospin forbidden transitions. The analysis of the 9C decay has been focused in the study of the 12.2 MeV state in 9B. The decay of this state to pαα occurs sequentially, partial decay branches through the 8Be(0+,2+) and 5Li(3/2−,1/2−) intermediate states have been determined. A BGT value of 1.20(15) is deduced, compared with the BGT-value of the mirror transition, a asymmetry factor δ=3.7(12) is obtained, the largest ever observed. A preview of β3α data from 12N decay is discussed.

Published
2002
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19. The [sup 34,35]Al beta decay to [sup 34,35]Si

Author

Z. Radivojevic, G. Walter, M. Ramdhane, F. Nowacki, Markku Oinonen, A. Knipper, E. Caurier, Ch. Miehé, Juha Äystö, P. Baumann, Ph. Dessagne, S. Nummela, and Ari Jokinen

Subjects
Nuclear physics, Physics, Branching fraction, Nuclear structure, Half-life, State (functional analysis), Atomic physics, Ground state, Parity (mathematics), Beta decay, Spin-½
Abstract

The 34,35Al beta decay was studied at the CERN on-line mass-separator ISOLDE by β-γ, β-γ-γ and β-n measurements. In the 34Al decay, the new data confirm the previous results and complement the level scheme in 34Si and 33Si. An intruder (2p-2h) 02+ state is proposed at 2.1 MeV in 34Si in agreement with different shell-model predictions but its decay is still unobserved. A 35Al β-decay scheme to 35Si bound and unbound states is established. The 35Al half life (41.6(22) ms) was measured with a good precision. The first 35Si level scheme including three levels at 911, 974 and 2169 keV with respectively Jπ=(3/2)−, (3/2)+ and (5/2)+ was obtained. The spin and parity values are consistent with a (5/2)+ assignment for the 35Al ground state. The value Pn=0.41(13) was also deduced. New information on the proton-neutron interaction in the (sd-fp) space is obtained.

Published
1999
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20. Recent beta-decay experiments on nuclei beyond [sup 56]Ni

Author

R. Kirchner, K.-H. Schmidt, Juha Äystö, Peter Dendooven, P. Mayet, C. Schlegel, M. Sawicka, H. Grawe, R. Borcea, H. Pentilla, M. La Commara, M. Górska, E. Roeckl, M. Karny, M. Rejmund, A. Niemenen, Ronald Schwengner, A. Płochocki, Margareta Hellström, Ari Jokinen, M. Gierlik, and Z. Janas

Subjects
Nuclear physics, Isotope, Branching fraction, Electron capture, law, Isotopes of copper, Chemistry, Nuclear structure, Mass spectrometry, Beta decay, Isotope separation, law.invention
Abstract

By using heavy-ion induced fusion-evaporation reactions at the on-line mass separator of GSI, we investigated {beta}-decay properties of the neutron-deficient isotopes {sup 56}Cu, {sup 57}Zn and {sup 61}Ga. The results will be presented and discussed in comparison with shell-model predictions.

Published
1999
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21. The fission ion guide: Present performance and future development

Author

Peter Dendooven, J. Äystö, A. Jokinen, A. Nieminen, V. S. Kolhinen, S. Hankonen, J. C. Wang, A. Honkanen, Markku Oinonen, J. Huikari, K. Peräjärvi, G. Lhersonneau, H. Penttilä, and M. Huhta

Subjects
Fission products, Ion beam, Isotope, Fission, Chemistry, Nuclear Theory, Particle accelerator, law.invention, Ion, Nuclear physics, law, Physics::Accelerator Physics, Ion trap, Nuclear Experiment, Beam (structure)
Abstract

Presently, the Jyvaskyla IGISOL facility delivers mass-separated beams of fission products with an intensity of 2700 ions/s per mb cross section. A further increase in yield is expected from the ongoing investigations into improving the design and understanding better the behavior of the fission ion guide. The study of new neutron-rich nuclei is hindered by the presence of different kinds of contaminants in the mass-separated beam: isobaric isotopes, isotopes of neighboring masses and doubly-charged ions. These problems will be solved by producing isotopically pure beams. We are developing an ion beam cooler+ion trap combination for this purpose.

Published
1998
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22. Fission product yields at intermediate energy

Author

O. I. Osetrov, W. H. Trzaska, A. A. Aleksandrov, V. A. Rubchenya, Andrey Kuznetsov, V. G. Lyapin, Ari Jokinen, A.V. Evsenin, J. Äystö, Peter Dendooven, J. C. Wang, D. N. Vakhtin, Yu. E. Penionzhkevich, S. Hankonen, S. V. Khlebnikov, and G. P. Tiourin

Subjects
Nuclear physics, Nuclear fission product, Fission products, Cold fission, Cluster decay, Fission, Chemistry, Neutron emission, Isotopes of samarium, Nuclear Theory, Fission product yield, Nuclear Experiment
Abstract

The results of experimental and theoretical studies of fission product yields in proton-induced fission of 238U are presented. The yields of neutron-rich Ni, Cu, Zn, Ga and Ge—isotopes were measured by 25 MeV protons and the ion guide-based isotope separator technique. The pre-neutron emission fragment mass distributions were measured by protons at energies Ep=20, 35, 50 and 60 MeV using time-of-flight method. The results indicate enhancement for superasymmetric mass division at intermediate excitation energy of the fissioning nucleus. A model calculation of fission products yields for fission of 238U by protons and neutrons is presented which predicts the formation cross sections for neutron-rich fission products. The influences of nuclear shells, odd-even effects and charge polarization are included in model description.

Published
1998
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23. TAS measurements for reactor physics and nuclear structure

Author

Algora, A., primary, Jordan, D., additional, Taín, J. L., additional, Rubio, B., additional, Agramunt, J., additional, Caballero, L., additional, Nácher, E., additional, Perez-Cerdan, A. B., additional, Molina, F., additional, Estevez, E., additional, Krasznahorkay, A., additional, Hunyadi, M. D., additional, Gulyás, J., additional, Vitéz, A., additional, Csatlós, M., additional, Csige, L., additional, Äysto, J., additional, Penttilä, H., additional, Rinta-Antila, S., additional, Moore, I., additional, Eronen, T., additional, Jokinen, A., additional, Nieminen, A., additional, Hakala, J., additional, Karvonen, P., additional, Kankainen, A., additional, Hager, U., additional, Sonoda, T., additional, Saastamoinen, A., additional, Rissanen, J., additional, Kessler, T., additional, Weber, C., additional, Ronkainen, J., additional, Rahaman, S., additional, Elomaa, V., additional, Burkard, K., additional, Hüller, W., additional, Batist, L., additional, Gelletly, W., additional, Nichols, A. L., additional, Yoshida, T., additional, Sonzogni, A. A., additional, Peräjärvi, K., additional, Demetriou, Paraskevi, additional, Julin, Rauno, additional, and Harissopulos, Sotirios, additional

Published
2011
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24. Astrophysical Reaction Rates Obtained By Indirect Techniques

Author

Tribble, R. E., primary, Al-Abdullah, T., additional, Alharbi, A., additional, Äystö, J., additional, Banu, A., additional, Burjan, V., additional, Carstoiu, F., additional, Chen, X., additional, Clark, H. L., additional, Davidson, T., additional, Fu, C., additional, Gagliardi, C. A., additional, Hardy, J. C., additional, Iacob, V. E., additional, Jokinen, J., additional, Kroha, V., additional, Lui, Y.-W., additional, McCleskey, M., additional, Mukhamedzhanov, A., additional, Nica, N., additional, Park, H. I., additional, Roeder, B., additional, Saastamoinen, A., additional, Simmons, E., additional, Tabacaru, G., additional, Tokimoto, Y., additional, Trache, L., additional, Woods, P. J., additional, Zhai, Y., additional, Tanihara, Isao, additional, Ong, Hooi Jin, additional, Tamii, Atsushi, additional, Kishimoto, Tadafumi, additional, Kajino, Toshitaka, additional, Kubono, Shigeru, additional, and Shima, Tatsushi, additional

Published
2010
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25. β-decay of [sup 23]Al and nova nucleosynthesis

Author

Saastamoinen, A., primary, Trache, L., additional, Banu, A., additional, Bentley, M. A., additional, Davinson, T., additional, Hardy, J. C., additional, Iacob, V. E., additional, Jenkins, D. G., additional, Jokinen, A., additional, McCleskey, M., additional, Roeder, B., additional, Simmons, E., additional, Tabacaru, G., additional, Tribble, R. E., additional, Woods, P. J., additional, Äystö, J., additional, Trache, Livius, additional, Smirnov, Alexei, additional, and Stoica, Sabin, additional

Published
2010
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26. Selected properties of nuclei at the magic shell closures from the studies of E1, M1 and E2 transition rates

Author

Mach, H., primary, Baluyut, A.-M., additional, Smith, D., additional, Ruchowska, E., additional, Köster, U., additional, Fraile, L. M., additional, Penttilä, H., additional, Äystö, J., additional, Boutami, R., additional, Bradley, H., additional, Braun, N., additional, Elomaa, V.-V., additional, Eronen, T., additional, Fransen, C., additional, Ghiţă, D. G., additional, Hakala, J., additional, Hauth, M., additional, Jokinen, A., additional, Jolie, J., additional, Karvonen, P., additional, Kessler, T., additional, Kurcewicz, W., additional, Lehmann, H., additional, Moore, I. D., additional, Nyberg, J., additional, Rahaman, S., additional, Rissanen, J., additional, Ronkainen, J., additional, Ronkanen, P., additional, Saastamoinen, A., additional, Sonoda, T., additional, Steczkiewicz, O., additional, Ugryumov, V., additional, Weber, C., additional, Jolie, Jan, additional, Zilges, Andreas, additional, Warr, Nigel, additional, and Blazhev, Andrey, additional

Published
2009
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27. Applications of the total absorption technique to improve reactor decay heat calculations: study of the beta decay of [sup 102,104,105]Tc

Author

Algora, A., primary, Jordan, D., additional, Taín, J. L., additional, Rubio, B., additional, Agramunt, J., additional, Perez-Cerdan, A. B., additional, Molina, F., additional, Caballero, L., additional, Nácher, E., additional, Krasznahorkay, A., additional, Hunyadi, M. D., additional, Gulyás, J., additional, Vitéz, A., additional, Csatlós, M., additional, Csige, L., additional, Äystö, J., additional, Penttilä, H., additional, Moore, I. D., additional, Eronen, T., additional, Jokinen, A., additional, Nieminen, A., additional, Hakala, J., additional, Karvonen, P., additional, Kankainen, A., additional, Saastamoinen, A., additional, Rissanen, J., additional, Kessler, T., additional, Weber, C., additional, Ronkainen, J., additional, Rahaman, S., additional, Elomaa, V., additional, Hager, U., additional, Rinta-Antila, S., additional, Sonoda, T., additional, Burkard, K., additional, Hüller, W., additional, Batist, L., additional, Gelletly, W., additional, Yoshida, T., additional, Nichols, A. L., additional, Sonzogni, A., additional, Peräjärvi, K., additional, Jolie, Jan, additional, Zilges, Andreas, additional, Warr, Nigel, additional, and Blazhev, Andrey, additional

Published
2009
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29. A Systematic Study of β− Decay of Neutron-Rich Rh and Ag Isotopes

Author

Wang, Y.-B., primary, Dendooven, P., additional, Huikari, J., additional, Jokinen, A., additional, Kolhinen, V. S., additional, Lhersonneau, G., additional, Nieminen, A., additional, Nummela, S., additional, Penttilä, H., additional, Peräjärvi, K., additional, Rinta-Antila, S., additional, Szerypo, J., additional, Wang, J. C., additional, and Äystö, J., additional

Published
2006
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30. Sulphur dioxide and sulphuric acid concentrations in the vicinity of Kilpilahti industrial area.

Author

Sarnela, Nina, Jokinen, Tuija, Junninen, Heikki, Hakala, Jani, Taipale, Risto, Patokoski, Johanna, Kajos, Maija, Schobesbergera, Siegfried, Lehtipalo, Katrianne, Sipilä, Mikko, Teittinen, Jukka, Westerholm, Henrik, Larnimaa, Kai, Petäjä, Tuukka, and Kulmala, Markku

Subjects
*ATMOSPHERIC sulfur dioxide, *SULFURIC acid, *INDUSTRIAL pollution, *PETROLEUM refineries, *EMISSIONS (Air pollution), *AIR masses, *METEOROLOGY statistical methods
Abstract

Industrial activity is a major source of sulphur compound emissions. The sulphuric acid and sulphur dioxide measurements in the vicinity of the industrial area and the oil refinery in Kilpilahti expressed great variation in concentration. The hourly mean values of concentration were categorized according to the area from where the air mass was travelling towards the measurement site. The statistical characteristics and diurnal behavior of emissions between these areas were significantly different. [ABSTRACT FROM AUTHOR]

Published
2013
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31. Molecular steps of neutral sulfuric acid and dimethylamine nucleation in CLOUD.

Author

Jokinen, Tuija, Sarnela, Nina, Sipilä, Mikko, Junninen, Heikki, Lehtipalo, Katrianne, Duplissy, Jonathan, and CLOUD Collaboration

Subjects
*CLOUDS, *ATMOSPHERIC nucleation, *SULFURIC acid, *DIMETHYLAMINE, *ATMOSPHERIC chemistry, *ATMOSPHERIC ionization, *ATMOSPHERIC pressure
Abstract

We have run a set of experiments in the CLOUD chamber at CERN, Switzerland, studying the effect of dimethylamine (DMA) on sulfuric acid (SA)-water nucleation using a nitrate based Chemical Ionization Atmospheric Pressure ionization Time-Of-Flight Mass Spectrometer (CI-APi-TOF). Experiment was designed to produce neutral high m/z SA-DMA clusters in close to atmospherically relevant conditions to be detected and characterized by the CI-APi-TOF. We aimed in filling up the gap in measurement techniques from molecular level up to climatically relevant aerosol particles and thus improve our understanding of the role of sulfuric acid and DMA in atmospheric nucleation. [ABSTRACT FROM AUTHOR]

Published
2013
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32. Chemistry of stabilized Criegee intermediates in the CLOUD chamber.

Author

Sarnela, Nina, Sipilä, Mikko, Jokinen, Tuija, Junninen, Heikki, and CLOUD Collaboration

Subjects
CLOUD chambers, INTERMEDIATES (Chemistry), OXIDATION, ATMOSPHERIC sulfur dioxide, SULFURIC acid, ATMOSPHERIC chemistry, ATMOSPHERIC pressure
Abstract

In atmospheric conditions the oxidation of sulphur dioxide to sulphuric acid in gas phase has been considered to be determined by the concentration of hydroxyl radical. Recently the significance of stabilized Criegee intermediate as an oxidizer of sulphuric acid has been brought out. In this study we investigated the oxidation of sulphur dioxide in the CLOUD chamber in conditions where the hydroxyl radical was removed. The concentration of formed sulphuric acid was measured with a chemical ionization atmospheric pressure interface time-offlight mass spectrometer and it was compared with the calculated yield of sulphuric acid. [ABSTRACT FROM AUTHOR]

Published
2013
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33. Evolution of α-pinene oxidation products in the presence of varying oxidizers: Negative APi-TOF point of view.

Author

Praplan, Arnaud P., Schobesberger, Siegfried, Junninen, Heikki, Rissanen, Matti, Sarnela, Nina, Jokinen, Tujia, Franchin, Alessandro, Duplissy, Jonathan, Sipilä, Mikko, Ehn, Mikael, Petäjä, Tuukka, Worsnop, Douglas R., Kulmala, Markku, and CLOUD Collaboration

Subjects
PINENE, OXIDATION, OXIDIZING agents, CLOUDS, OZONOLYSIS, MICROCLUSTERS, ATMOSPHERIC chemistry
Abstract

Laboratory experiments conducted in the frame of the CLOUD project at CERN investigated the oxidation of α-pinene oxidation products in a carefully controlled environment and with different oxidation conditions: 1) pure ozonolysis (with the use of an hydroxyl radical (·OH) scavenger), 2) ozonolysis without use of a scavenger, and 3) pure ·OH oxidation using nitrous acid (HONO) to produce ·OH. The anions and negatively charged clusters present in the chamber were analyzed and their chemical composition compared for the different oxidation pathways. [ABSTRACT FROM AUTHOR]

Published
2013
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34. Aerosol nucleation and growth in a mixture of sulfuric acid/alpha-pinene oxidation products at the CERN CLOUD chamber.

Author

Tröstl, Jasmin, Bianchi, Federico, Kürten, Andreas, Rondo, Linda, Simon, Mario, Sarnela, Nina, Jokinen, Tuija, Heinritzi, Martin, Dommen, Josef, Kirkby, Jasper, Weingartner, Ernest, Baltensperger, Urs, and CLOUD Collaboration

Subjects
ATMOSPHERIC aerosols, ATMOSPHERIC nucleation, SULFURIC acid, PINENE, CLOUD chambers, CONDENSATION (Meteorology), NANOPARTICLES
Abstract

The role of α-pinene in aerosol nucleation and growth was investigated using the CERN CLOUD chamber, a nano scanning mobility particle sizer (nanoSMPS) and several condensation particle counters (CPCs) with different diameter cut-offs. Different oxidation conditions for α-pinene - OH· vs. ozone oxidation - were considered to investigate their contributions to particle nucleation and growth. Results from the latest CERN experiment from fall 2012 (CLOUD 7) are presented. [ABSTRACT FROM AUTHOR]

Published
2013
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35. Nucleation of H2SO4 and oxidized organics in CLOUD experiment.

Author

Sipilä, Mikko, Sarnela, Nina, Jokinen, Tuija, Nieminen, Tuomo, Almeida, Joao, Tröstl, Jasmin, Lehtipalo, Katrianne, Duplissy, Jonathan, Junninen, Heikki, and CLOUD Collaboration

Subjects
ATMOSPHERIC nucleation, SULFURIC acid, ATMOSPHERIC sulfur compounds, OXIDATION, ATMOSPHERIC aerosols, CLOUD chambers
Abstract

The research of atmospheric new particle formation has proceeded lately as the role of sulphuric acid has been established. Still, the roles of other atmospheric compounds in nucleation remain largely unclear. To clarify the first steps of atmospheric new particle formation extensive nucleation experiments were performed in CLOUD chamber in 2012. Especially the role of oxidations products of α-pinene was studied in detail. The experiments provided new information about the part of oxidized organics in nucleation. [ABSTRACT FROM AUTHOR]

Published
2013
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36. Measurement of neutral sulfuric acid-dimethylamine clusters using CI-APi-TOF-MS.

Author

Simon, Mario, Kürten, Andreas, Jokinen, Tuija, Sarnela, Nina, Sipilä, Mikko, Rondo, Linda, Ehrhart, Sebastian, Junninen, Heikki, Hutterli, Manuel, Kirkby, Jasper, Worsnop, Douglas R., Curtius, Joachim, and CLOUD Collaboration

Subjects
SULFURIC acid, DIMETHYLAMINE, MICROCLUSTERS, ATMOSPHERIC aerosols, CLOUD chambers, ATMOSPHERIC pressure
Abstract

Recent studies suggest that dimethylamine could be a key ternary species in the formation and early growth of atmospheric aerosol particles. We report on nucleation studies for the ternary system of sulfuric acid, water and dimethylamine which have been performed at the CERN CLOUD chamber. These studies were conducted at atmospherically relevant concentrations of sulfuric acid and dimethylamine at 278 K and 38% RH. Two newly developed Chemical Ionization-Atmospheric Pressure interface-Time of Flight-Mass Spectrometers (CIAPi-TOF-MS) were used to measure the time-resolved concentration of neutral clusters containing sulfuric acid and dimethylamine. Results from other instrumental techniques are included in the analysis as well to obtain a deeper insight into the occurring mechanisms. It is the first time that the neutral nucleation pathway has been studied in such detail from the early generation of sulfuric acid monomers up to particle sizes reaching several nanometers. [ABSTRACT FROM AUTHOR]

Published
2013
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37. Contribution of oxidized organic compounds to nanoparticle growth.

Author

Nieminen, Tuomo, Franchin, Alessandro, Lehtipalo, Katrianne, Schobesberger, Siegfried, Sarnela, Nina, Jokinen, Tuija, Duplissy, Jonathan, Sipilä, Mikko, Kulmala, Markku, and CLOUD Collaboration

Subjects
ORGANIC compounds, NANOPARTICLES, CRYSTAL growth, ATMOSPHERIC nucleation, CLOUD chambers, OXIDATION, AMMONIA, HYDROXYL group, SULFURIC acid
Abstract

Nucleation and subsequent growth of particles was studied in the CLOUD7 chamber experiment at Cern. Experiments were performed in varying concentrations of sulphuric acid, ammonia, dimethylamine and α-pinene, and using both ozone and hydroxyl radicals as oxidizers. Particle growth rates were determined at size ranges <1.5 nm, 1.5-3 nm, and >3nm. Comparison of the growth to the amount oxidized organics in the mass range 300-450 amu was made. [ABSTRACT FROM AUTHOR]

Published
2013
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38. Recent negative ion source activity at JYFL.

Author

Kalvas, T., Tarvainen, O., Komppula, J., Laitinen, M., Sajavaara, T., Koivisto, H., Jokinen, A., and Dehnel, M. P.

Subjects
ION sources, HYDROGEN ions, ION accelerators, ION beam lithography, X-ray spectroscopy, PERMANENT magnets, ELECTRODES
Abstract

A filament-powered multicusp ion source for production of H- has been developed for the Jyväskylä Pelletron accelerator for use in ion beam lithography and particle induced X-ray emission applications. The source can be considered conventional with the exception of the filter field being created with an electric magnet for continuous adjustability. A permanent magnet dipoleantidipole electron dump is integrated in the puller electrode. The source provides 50 μA H- beam at 10 keV energy with 0.019 mm mrad 95 % normalized rms emittance through a 2 mm aperture. Lower emittance is achievable by changing the plasma electrode insert to a smaller aperture one if application requires. A new commercial MCC30/15 cyclotron has been installed at the Jyväskylä accelerator laboratory providing 30MeV H+ and 15Mev D+ for use in nuclear physics experiments and applications. The ion source delivered with the cyclotron is a a filament-powered multicusp source capable of about 130 h continuous operation at 1 mA H- output between filament changes. The ion source is located in the cyclotron vault and therefore a significant waiting time for the vault cooldown is required before filament change is possible. This kind of operation is not acceptable as 350 h and longer experiments are expected. Therefore a project for developing a CW 13.56 MHz RF ion source has been initiated. A planar RF antenna replacing the filament back plate of the existing TRIUMF-type ion source has been used in the first tests with 240 μA of H- and 21 mA of electrons measured at 1.5 kW of RF power. Tests with higher RF power levels were prevented by electron beam induced sparking. A new plasma chamber has been built and a new extraction is being designed for the RF ion source. The extraction code IBSimu has recently gone through a major update on how smooth electrode surfaces are implemented in the Poisson solvers. This has made it possible to implement a fast multigrid solver with low memory consumption. Also a method has been made to import 3D CAD geometries into simulations. [ABSTRACT FROM AUTHOR]

Published
2013
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39. Decay Spectroscopy for Nuclear Astrophysics: β-delayed Proton Decay.

Author

Trache, L., Simmons, E., Spiridon, A., McCleskey, M., Roeder, B. T., Tribble, R. E., Saastamoinen, A., Jokinen, A., Aysto, J., Davinson, T., Woods, P. J., Pollacco, E., Kebbiri, M., and Pascovici, G.

Subjects
NUCLEAR astrophysics, PROTON decay, SPECTRUM analysis, SILICON diodes, OPTICAL resolution, GAMMA rays, ALUMINUM isotopes, PROTON capture
Abstract

Decay spectroscopy is one of the oldest indirect methods in nuclear astrophysics. We have developed at TAMU techniques to measure beta- and beta-delayed proton decay of sd-shell, proton-rich nuclei. The short-lived radioactive species are produced in-flight, separated, then slowed down (from about 40 MeV/u) and implanted in the middle of very thin Si detectors. These allowed us to measure protons with energies as low as 200 keV from nuclei with lifetimes of 100 ms or less. At the same time we measure gamma-rays up to 8 MeV with high resolution HPGe detectors. We have studied the decay of 23Al, 27P, 31Cl, all important for understanding explosive H-burning in novae. The technique has shown a remarkable selectivity to beta-delayed charged-particle emission and works even at radioactive beam rates of a few pps. The states populated are resonances for the radiative proton capture reactions 22Na(p,γ)23Mg (crucial for the depletion of 22Na in novae), 26mAl(p,γ)27Si and 30P(p,γ)31S (bottleneck in novae and XRB burning), respectively. More recently we have radically improved the technique using a gas based detector we call AstroBox. [ABSTRACT FROM AUTHOR]

Published
2011
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40. Study of excited states of 31S through beta-decay of 31Cl for nucleosynthesis in ONe novae.

Author

Saastamoinen, A., Trache, L., Banu, A., Bentley, M. A., Davinson, T., Hardy, J. C., Iacob, V. E., Jokinen, A., McCleskey, M., Roeder, B., Simmons, E., Tabacaru, G., Tribble, R. E., Woods, P. J., and Äystö, J.

Subjects
SULFUR isotopes, CHLORINE, NUCLEAR excitation, NUCLEAR explosions, RADIOACTIVE decay, NUCLEOSYNTHESIS, GIRDERS, NUCLEAR counters
Abstract

We have produced an intense and pure beam of 31Cl with the MARS Separator at the Texas A&M University and studied β-decay of 31Cl by implanting the beam into a novel detector setup, capable of measuring β-delayed protons and γ-rays simultaneously. From our data, we have established decay scheme of 31Cl, found resonance energies with 1 keV precision, have measured its half-life with under 1% accuracy, found its Isobar Analog State decay and by using the IMME obtained an improved mass excess for its ground state. In this contribution, a description of the used method along with selected preliminary experimental results are given and their relevance for novae nucleosynthesis discussed. [ABSTRACT FROM AUTHOR]

Published
2011
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41. β-decay of 23Al and nova nucleosynthesis.

Author

Saastamoinen, A., Trache, L., Banu, A., Bentley, M. A., Davinson, T., Hardy, J. C., Iacob, V. E., Jenkins, D. G., Jokinen, A., McCleskey, M., Roeder, B., Simmons, E., Tabacaru, G., Tribble, R. E., Woods, P. J., and Äystö, J.

Subjects
RADIOACTIVE decay, COSMOCHEMISTRY, NUCLEAR reactions, BRANCHING ratios, CONSTITUTION of matter, DECAY schemes (Radioactivity), PROTONS
Abstract

We have studied the β-decay of 23Al with a novel detector setup at the focal plane of the MARS separator at the Texas A&M University to resolve existing controversies about the proton intensities of the IAS in 23Mg and to determine the absolute proton branching ratios by combining our results to the latest γ-decay data. Experimental technique, results and the relevance for nova nucleosynthesis are discussed. [ABSTRACT FROM AUTHOR]

Published
2010
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43. Applications of the total absorption technique to improve reactor decay heat calculations: study of the beta decay of 102,104,105Tc.

Author

Algora, A., Jordan, D., Taín, J. L., Rubio, B., Agramunt, J., Perez-Cerdan, A. B., Molina, F., Caballero, L., Nácher, E., Krasznahorkay, A., Hunyadi, M. D., Gulyás, J., Vitéz, A., Csatlós, M., Csige, L., Äystö, J., Penttilä, H., Moore, I. D., Eronen, T., and Jokinen, A.

Subjects
NUCLEAR research, MASS attenuation coefficients, RADIATION, NUCLEAR fission, NUCLEAR fuels, NUCLEAR energy, BETA decay
Abstract

The decay heat of the fission products plays an important role in predicting the heat-up of nuclear fuel after reactor shutdown. This form of energy release is calculated as the sum of the energy-weighted activities of all fission products P(t) = ΣEiλiNi(t), where Ei is the decay energy of nuclide i (gamma and beta component), λi is the decay constant of nuclide i and Ni(t) is the number of nuclide i at cooling time t. Even though the reproduction of the measured decay heat has improved in recent years, there is still a long standing discrepancy at t∼1000 s cooling time for some fuels. A possible explanation for this disagreement can been found in the work of Yoshida et al. [1], who demonstrated that an incomplete knowledge of the β-decay of some Tc isotopes could be the source of the systematic discrepancy. Motivated by [1], we have recently measured the β-decay process of some Tc isotopes using a total absorption spectrometer at the IGISOL facility in Jyväskylä. The results of the measurements are discussed, along with their impact on summation calculations. [ABSTRACT FROM AUTHOR]

Published
2009
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44. Mass measurements and proton binding energies near the Z = N line below 100Sn.

Author

Jokinen, Ari

Subjects
*ION traps, *ATOMIC mass, *PENNING trap mass spectrometry, *NUCLEAR astrophysics, *NUCLEAR structure
Abstract

Ion traps have been applied widely for measurements of atomic masses with unprecedented precision. JYFLTRAP tandem Penning trap, located in the Department of Physics, University of Jyväskylä, has provided a vast amount of new data in the vicinity of the N = Z line contributing to nuclear astrophysics, nuclear structure studies, and fundamental questions of weak interaction. [ABSTRACT FROM AUTHOR]

Published
2007
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45. Nuclear structure effects probed by precision atomic mass measurements.

Author

Jokinen, A., Elomaa, V.-V., Eronen, T., Hager, U., Hakala, J., Kankainen, A., Moore, I., Rahaman, S., Rinta-Antila, S., Sonoda, T., and Äystö, J.

Subjects
*NUCLEAR structure, *NUCLEAR physics, *PHYSICS, *ATOMIC mass, *MASS (Physics)
Abstract

The manipulation of ion beams by trapping techniques at the IGISOL facility is described. Examples of applications of ion traps in spectroscopic studies and mass spectrometry are given. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2006
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46. Beta-delayed multi-particle emission in proton rich nuclei

Author

Borge, M. J. G., primary, Axelsson, L., additional, Äystö, J., additional, Bergmann, U. C., additional, Boutami, R., additional, Deendoven, P., additional, Fraile, L. M., additional, Fynbo, H. O. U., additional, Honkanen, A., additional, Hornshøj, P., additional, Huikari, J., additional, Jokinen, A., additional, Jonson, B., additional, Markenroth, K., additional, Martel, I., additional, Mukha, I., additional, Nilsson, T., additional, Nyman, G., additional, Oinonen, M., additional, Prezado, Y., additional, Riisager, K., additional, Tengblad, O., additional, and Rolander, K. Wilhelmsen, additional

Published
2002
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47. Spectroscopic studies of neutron-deficient light nuclei: decay properties of 21Mg, 25Si and 26P.

Author

Thomas, J.-C., Achouri, L., Äystö, J., Béraud, R., Blank, B., Canchel, G., Czajkowski, S., Dendooven, P., Ensallem, A., Giovinazzo, J., Guillet, N., Honkanen, J., Jokinen, A., Laird, A., Lewitowicz, M., Longour, C., de Oliveira Santos, F., and Stanoiu, M.

Subjects
SPECTRUM analysis, NUCLEAR physics, NEUTRONS, PROTONS, HALF-life (Nuclear physics)
Abstract

Neutron-deficient nuclei with Tz equals to -3/2 and -2 have been produced at the GANIL/LISE3 facility in fragmentation reactions of a 95 MeV/u 36Ar primary beam in a 12C target. For the first time, β-delayed proton and β-γ emission has been simultaneously observed in the decay of 21Mg, 25Si and 26P. The decay scheme of the latter is proposed and the Gamow-Teller strength distribution in its β decay is compared to shell-model calculations based on the USD interaction. The B(GT) values derived from the absolute measurement of the β-branching ratios are in agreement with the quenching factor of about 60% obtained for allowed Gamow-Teller transitions in this mass region. A precise half-life of 43.7 (6) ms was determined for 26P, the β-2p emission of which was studied. The expected contribution of spectroscopic studies of neutron-rich nuclei is discussed with respect to the mirror asymmetry phenomenon occuring in analogous β decays. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2003
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48. Recent beta-decay experiments on nuclei beyond [sup 56]Ni

Author

Roeckl, E., primary, Äystö, J., additional, Borcea, R., additional, Dendooven, P., additional, Gierlik, M., additional, Górska, M., additional, Grawe, H., additional, Hellström, M., additional, Jokinen, A., additional, Karny, M., additional, Janas, Z., additional, Kirchner, R., additional, La Commara, M., additional, Mayet, P., additional, Niemenen, A., additional, Pentillä, H., additional, Płochocki, A., additional, Rejmund, M., additional, Sawicka, M., additional, Schlegel, C., additional, Schmidt, K., additional, and Schwengner, R., additional

Published
1999
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49. Gamow-Teller and Fermi decay of N=Z nuclei above A=70

Author

Dessagne, Ph., primary, Applebe, D., additional, Axelsson, L., additional, Blank, B., additional, Borge, M. J. G., additional, Bruce, A. M., additional, Catford, W. N., additional, Chandler, C., additional, Clark, R. M., additional, Cullen, D. M., additional, Czajkowski, S., additional, Daugas, J. M., additional, Fleury, A., additional, Frankland, L., additional, Narro, J. Garcés, additional, Gelletly, W., additional, Giovinazzo, J., additional, Greenhalgh, B., additional, Grzywacz, R., additional, Harder, M., additional, Huck, A., additional, Jokinen, A., additional, Jones, K. L., additional, Kelsall, N., additional, Knipper, A., additional, Kszczot, T., additional, Lewitowicz, M., additional, Longour, C., additional, Miehé, C., additional, Page, R. D., additional, Pearson, C. J., additional, Piqueras, I., additional, Ramdhane, M., additional, Rauch, V., additional, Reed, A. T., additional, Regan, P. H., additional, Sorlin, O., additional, Tengblad, O., additional, and Wadsworth, R., additional

Published
1999
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50. The [sup 34,35]Al beta decay to [sup 34,35]Si

Author

Nummela, S., primary, Baumann, P., additional, Caurier, E., additional, Dessagne, Ph., additional, Jokinen, A., additional, Knipper, A., additional, Miehé, Ch., additional, Nowacki, F., additional, Oinonen, M., additional, Radivojevic, Z., additional, Ramdhane, M., additional, Walter, G., additional, and Äystö, J., additional

Published
1999
Full Text
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