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Your search keyword '"Wörtche, H. J."' showing total 23 results
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23 results on '"Wörtche, H. J."'

2. High-precision (p,t) reaction to determine Al-25(p,gamma)Si-26 reaction rates

Author

Matic, A., van den Berg, A. M., Harakeh, M. N., Wörtche, H. J., Berg, G. P. A., Couder, M., Goerres, J., LeBlanc, P., O'Brien, S., Wiescher, M., Fujita, K., Hatanaka, K., Sakemi, Y., Shimizu, Y., Tameshige, Y., Tamii, A., Yosoi, M., Adachi, T., Fujita, Y., Shimbara, Y., Fujita, H., Wakasa, T., Brown, B. A., Schatz, H., Research unit Nuclear & Hadron Physics, and Research unit Astroparticle Physics

Subjects
AL-26 PRODUCTION, NUCLEOSYNTHESIS, ENERGY-LEVELS, NUCLEI, THERMONUCLEAR REACTION-RATES, LINE, GRAND-RAIDEN, SPECTROMETER, EMISSION, STARS
Abstract

Since the identification of ongoing Al-26 production in the universe, the reaction sequence Mg-24(p,gamma)Al-25(beta(+)nu)Mg-25(p,gamma)Al-26 has been studied intensively. At temperatures where the radiative capture on Al-25 (t(1/2) = 7.2 s) becomes faster than the beta(+) decay, the production of Al-26 can be reduced due to the depletion of Al-25. To determine the resonances relevant for the Al-25(p,gamma) Si-26 bypass reaction, we measured the Si-28(p,t)Si-26 reaction with high-energy precision using the Grand Raiden spectrometer at the Research Center for Nuclear Physics, Osaka. Several new energy levels were found above the p threshold and for known states excitation energies were determined with smaller uncertainties. The calculated stellar rates of the bypass reaction agree well with previous results, suggesting that these rates are well established.

Published
2010

3. High-precision ( p,t) reaction to determine 25Al( p,γ )26Si reaction rates

Author

Matic, A., Berg, A. M., Harakeh, M. N., Wörtche, H. J., Berg, G. P. A., Couder, M., Görres, J., Leblanc, P., O’Brien, S., Wiescher, M., Fujita, K., Hatanaka, K., Sakemi, Y., Shimizu, Y., Tameshige, Y., Tamii, A., Yosoi, M., Adachi, T., Fujita, Y., Shimbara, Y., Fujita, H., Wakasa, T., Brown, B. A., and Schatz, H.

Subjects
26Al 24Mg(p, γ )25Al(β+ν)25Mg(p, γ )26Al Grand Raiden spectrometer
Abstract

Since the identification of ongoing 26Al production in the universe, the reaction sequence 24Mg(p,γ )25Al(β+ν)25Mg(p,γ )26Al has been studied intensively. At temperatures where the radiative capture on 25Al (t1/2 = 7.2 s) becomes faster than the β+ decay, the production of 26Al can be reduced due to the depletion of 25Al. To determine the resonances relevant for the 25Al(p,γ )26Si bypass reaction, we measured the 28Si(p,t )26Si reaction with high-energy precision using the Grand Raiden spectrometer at the Research Center for Nuclear Physics, Osaka. Several new energy levels were found above the p threshold and for known states excitation energies were determined with smaller uncertainties. The calculated stellar rates of the bypass reaction agree well with previous results, suggesting that these rates are well established.

Published
2010

4. Splitting of the Pygmy Dipole Resonance

Author

Savran, D., Den Berg, Adriaan M., Endres, J., Muhsin N. Harakeh, Pietralla, N., Sonnabend, K., Victor Stoica, Wörtche, H. J., Zilges, A., KVI - Center for Advanced Radiation Technology, and Research unit Astroparticle Physics

Published
2010

5. High-precision (p,t) reaction measurement to determine Ne-18(alpha,p)Na-21 reaction rates

Author

Matic, A., van den Berg, A. M., Harakeh, M. N., Wörtche, H. J., Berg, G. P. A., Couder, M., Fisker, J. L., Goerres, J., LeBlanc, P., O'Brien, S., Wiescher, M., Fujita, K., Hatanaka, K., Sakemi, Y., Shimizu, Y., Tameshige, Y., Tamii, A., Yosoi, M., Adachi, T., Fujita, Y., Shimbara, Y., Fujita, H., Wakasa, T., Hess, P. O., Brown, B. A., Schatz, H., Research unit Nuclear & Hadron Physics, and Research unit Astroparticle Physics

Subjects
SEMIMICROSCOPIC ALGEBRAIC DESCRIPTION, WAITING POINTS, ELASTIC-SCATTERING, SPECTROSCOPIC AMPLITUDES, X-RAY-BURSTS, LOW-ENERGY RESONANCES, CLUSTER STATES, ACCRETING NEUTRON-STARS, RP-PROCESS, SPECTROMETER GRAND RAIDEN
Abstract

x-ray bursts are identified as thermonuclear explosions in the outer atmosphere of accreting neutron stars. The thermonuclear runaway is fueled by the alpha p process that describes a sequence of (alpha,p) reactions triggered by the Ne-18(alpha,p)Na-21 breakout reaction from the hot CNO cycles. We studied the level structure of the compound nucleus Mg-22 by measuring the Mg-24(p,t)Mg-22 reaction at the Grand Raiden spectrometer at Research Center for Nuclear Physics, Osaka. A large number of alpha-unbound states was identified and precise excitation energies were determined. Based on shell model and alpha-cluster model calculations we predict the level parameters for determining the stellar reaction rate of Ne-18(alpha,p)Na-21 for a wide temperature range. x-ray burst simulations have been performed to study the impact of the reaction on the x-ray burst luminosity.

Published
2009

7. High-precision (p,t) reaction measurement to determine 18Ne(alpha,p)21Na reaction rates

Author

Matic, A., Berg, A. M., Harakeh, M. N., Wörtche, H. J., Berg, G. P. A., Couder, M., Fisker, J. L., Görres, J., Leblanc, P., O'Brien, S., Wiescher, M., Fujita, K., Hatanaka, K., Sakemi, Y., Shimizu, Y., Tameshige, Y., Tamii, A., Yosoi, M., Adachi, T., Fujita, Y., Shimbara, Y., Fujita, H., Wakasa, T., Hess, P. O., Brown, B. A., and Schatz, H.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, Nuclear Experiment
Abstract

x-ray bursts are identified as thermonuclear explosions in the outer atmosphere of accreting neutron stars. The thermonuclear runaway is fueled by the alphap process that describes a sequence of (alpha,p) reactions triggered by the 18Ne(alpha,p)21Na breakout reaction from the hot CNO cycles. We studied the level structure of the compound nucleus 22Mg by measuring the 24Mg(p,t)22Mg reaction at the Grand Raiden spectrometer at Research Center for Nuclear Physics, Osaka. A large number of alpha-unbound states was identified and precise excitation energies were determined. Based on shell model and alpha-cluster model calculations we predict the level parameters for determining the stellar reaction rate of 18Ne(alpha,p)21Na for a wide temperature range. x-ray burst simulations have been performed to study the impact of the reaction on the x-ray burst luminosity.

Published
2009

9. Evidence for direct neutron decay of the isoscalar giant dipole resonances in Zr-90, Sn-116, and Pb-208

Author

Hunyadi, M. D., van den Berg, A. M., Davids, B. S., Harakeh, M. N., de Huu, M.A., Wörtche, H. J., Csatlós, M., Gulyas, J., Krasznahorkay, A., Sohler, D., Garg, U., Fujiwara, M., Blasi, N., Research unit Nuclear & Hadron Physics, Research unit Astroparticle Physics, and KVI - Center for Advanced Radiation Technology

Subjects
INELASTIC ALPHA-SCATTERING, PROTON EXCITATION, BREATHING-MODE, NUCLEI, STATES, MONOPOLE-RESONANCE, COMPRESSION MODES, Nuclear Theory, PARTICLE DECAY, Nuclear Experiment, COMPONENT, REGION
Abstract

The direct and statistical neutron decay of the isoscalar giant dipole resonance was studied in Zr-90, Sn-116, and Pb-208 using the (alpha,alpha(')n) reaction at a bombarding energy of 200 MeV. The spectra of fast decay neutrons populating valence hole-states of the Z,N-1 nuclei were analyzed, and estimates for the branching ratios were determined. The results were compared to recent continuum random-phase approximation calculations.

Published
2007

10. An appearance experiment to search for $\nu_{\mu} $\ \nu_{\tau}$ oscillations in the CNGS beam: experimental proposal

Author

Güler, M, Serin-Zeyrek, M, Tolun, P, Zeyrek, M T, Duchesneau, D, Degré, A, Favier, Jean, Pessard, H, Muciaccia, M T, Righini, P, Simone, S, Lu, S L, Zhou, S J, Winter, Klaus, Borer, K, Haeberli, C, Hess, M, Klingenberg, R, Moser, U, Pretzl, Klaus P, Waelchli, T, Weber, M, Giacomelli, G, Mandrioli, G, Patrizii, L, Serra, P, Sioli, M, Sirri, G, Van Beek, G, Vilain, P, Wilquet, G, Spinetti, M, Votano, L, Ogawa, S, Shibuya, H, Autiero, D, Camilleri, L L, Di Lella, Luigi, Dupraz, J P, Fabre, Jean-Paul, Petti, R, Schilly, P, Sohlbach, H, Woltersdorf, H, Goldberg, J, Khalifa, M, Büsser, F W, Garfagnini, A, Geiser, A, Höpfner, K, Koppitz, B, Naroska, Beate, Schmidt-Parzefall, W, Van Staa, R, Kodama, K, Ushida, N, Aoki, S, Hara, T, Chaussard, L, Chemarin, M, Déclais, Y, Jönsson, P E, Katsanevas, S, Laktineh, I, Marteau, J, Moret, G, D'Ambrosio, N, Boschan, P, Frekers, D, Kellmann, T, Kueckmann, J, Schmand, J, Wörtche, H J, Wolff, T, Hoshino, K, Komatsu, M, Miyanishi, M, Nakamura, M, Nakano, T, Niwa, K, Sato, O, Bruski, N, Buontempo, S, Carbonara, F, Cocco, A G, De Lellis, G, De Rosa, G, Ereditato, A, Fiorillo, G, Kawamura, T, Messina, M, Migliozzi, P, Saggese, L, Strolin, P, Tioukov, V, Boucrot, J, Campagne, J E, Merkel, B, Repellin, J P, Veillet, J J, Brugnera, R, Dal Corso, F, Dusini, S, Fanin, C, Stanco, L, Rosa, G, Beyer, M, Schröder, H, Waldi, R, Barbuto, E, Bozza, C, Grella, G, Romano, G, Sorrentino, S, Arnold, R, Baussan, E, Dracos, M, Guyonnet, J L, Strub, R, He, M, Li Jing Yi, Feng Cun Feng, Fu, Y, Xue Liang, Sato, Y, Tezuka, I, Stipcevic, M, Ljubicic, A, and Jakovcic, K

Subjects
Detectors and Experimental Techniques
Published
2000

11. Progress report towards an experiment to study atmospheric neutrino oscillations with a massive magnetized iron detector

Author

Ambrosio, M, Amelchakov, M, Antonioli, P, Aprile, E, Aramo, C, Aynutdinov, V, Bari, G, Benaceur, R, Bencivenni, G, Bologna, G, Bonesini, M, Bruni, G, Bruski, N, Büsser, F W, Campagne, J E, Chernov, D, Chemarin, M, Curioni, A, Chaussard, L, Déclais, Y, Duschesneau, D, Ezubchenko, A, Favier, Jean, Frekers, D, Galeotti, P, Garfagnini, A, Geiser, A, Gharbi, F, Giusti, P, Golubkov, D Y, Goloubev, N A, Gninenko, S N, Gustavino, C, Heinzelmann, G, Hermel, R, Höpfner, K, Jönsson, P E, Katsanevas, S, Kindin, V, Kirsanov, M M, Klanner, Robert, Koppitz, B, Kokoulin, R P, Kompaniets, K, Konovalov, A, Kovzelev, A, Laktineh, I, Mannocchi, G, Marteau, J, Merkel, B, Monacelli, P, Moret, G, Murtas, F, Murtas, G P, Nania, R, Naroska, Beate, Negri, P, Ordine, A, Paganoni, M, Pesci, A, Pessard, H, Periale, L, Petrukhin, A A, Picchi, P, Pullia, Antonio, Ragazzi, S, Redaelli, N G, Repellin, J P, Rondeshagen, D, Ronga, F, Sartorelli, G, Satta, L, Schmidt-Parzefall, W, Spinetti, M, Souga, C, Tabarelli de Fatis, T, Terranova, F, Trabelsi, A, Trinchero, G C, Van Staa, R, Veillet, J J, Villone, B, Votano, L, Winter, Klaus, Wörtche, H J, Wolff, T, Yanson, E, and Yashin, Yu P

Subjects
Detectors and Experimental Techniques
Published
1999

13. Low-lying GT+ strength in 64Co studied via the 64Ni(d,2He)64Co reaction

Author

Popescu, L. A., Bäumer, C., Den Berg, Adriaan M., Frekers, D., Frenne, D., Fujita, Y., Grewe, E. W., Haefner, P., Muhsin N. Harakeh, Mátyás Hunyadi, Huu, M. A., Jacobs, E., Johansson, H., Korff, A., Negret, A., Neumann-Cosel, P., Rakers, S., Richter, A., Ryezayeva, N., Shevchenko, A., Simon, H., Wörtche, H. J., KVI - Center for Advanced Radiation Technology, and Research unit Astroparticle Physics

14. Determination of Gamow-Teller strength distribution from the odd-odd nucleus 50V measured through 50V(D,2He)50 Ti and astrophysical implications

Author

Bäumer, C., Den Berg, Adriaan M., Davids, B. S., Frekers, D., Frenne, D., Grewe, E. W., Haefner, P., Muhsin N. Harakeh, Mátyás Hunyadi, Huu, M. A., Jacobs, E., Junk, B., Korff, A., Langanke, K., Martinez-Pinedo, G., Negret, A., Neumann-Cosel, P., Popescu, L. A., Rakers, S., Richter, A., Wörtche, H. J., Hofmann, F., KVI - Center for Advanced Radiation Technology, and Onderzoeksgroep Astrodeeltjes Fysica

15. Measuring the (d,${^2}He) reaction with the focal-plane detection system of the BBS magnetic spectrometer at AGOR

Author

Rakers, S., Ellinghaus, F., Bassini, R., Bäumer, C., Frekers, D., Frenne, D., Hagemann, M., Hartig, M., Heyse, J., Jacob, C., Mielke, M., Schmidt, R., Henderson, R., Den Berg, Adriaan M., Hannen, V. M., Muhsin N. Harakeh, Huu, M. A., Schippers, Jacobus M., Werf, S. Y., Wörtche, H. J., KVI - Center for Advanced Radiation Technology, and Onderzoeksgroep Astrodeeltjes Fysica

18. Splitting of the pygmy dipole resonance observed in the (α,α’γ) reaction

Author

Endres, J., Savran, D., Butler, P., Peter Dendooven, Muhsin N. Harakeh, Harissopulos, S., Hasper, J., Herzberg, R. D., Krücken, R., Lagoyannis, A., Pietralla, N., Popescu, L. A., Scheck, M., Siebenhühner, F., Sonnabend, K., Stoica, V., Wörtche, H. J., Zilges, A., KVI - Center for Advanced Radiation Technology, and Research unit Nuclear & Hadron Physics

19. Study of the Pygmy Dipole Resonance with hadronic and electromagnetic probes

Author

Endres, J., Zilges, A., Litvinova, E., Savran, D., Butler, P. A., Herzberg, R. D., Muhsin N. Harakeh, Victor Stoica, Wörtche, H. J., Harissopulos, S., Lagoyannis, A., Krücken, R., Ring, P., Pietralla, N., Yu Ponomarev, V., Scheck, M., Sonnabend, K., Popescu, L. A., and KVI - Center for Advanced Radiation Technology

20. Recent results from the decay studies of high-energy isoscalar giant resonances

Author

Hunyadi, M., Den Berg, A. M., Blasig, N., Csatlós, M., Csige, L., Davids, B., Fujiwara, M., Garg, U., Gulyás, J., Harakeh, M. N., Marc de Huu, Krasznahorkay, A., Sohler, D., Wörtche, H. J., Research unit Astroparticle Physics, and Research unit Nuclear & Hadron Physics

Subjects
INELASTIC ALPHA-SCATTERING, PROTON EXCITATION, MONOPOLE, COMPRESSION MODES, Nuclear Theory, DIPOLE RESONANCE, PB-208, Nuclear Experiment
Abstract

The direct and statistical neutron decay of the isoscalar giant dipole resonance and a continuum region at higher excitation energy has been studied in Zr-90, Sn-116 and Pb-208 using the (alpha, alpha'n) reaction at a bombarding energy of 200 MeV. The spectra of fast decay neutrons populating valence neutron-hole states were analyzed, and estimates for the branching ratios were determined to compare to recent theoretical predictions. The observation of the direct nucleon decay channels helped to separate giant resonance strengths and suppress the underlying background and continuum, which lead to an indication for the existence of the first overtone mode of the isoscalar giant quadrupole resonance.

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