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Your search keyword '"Den Berg, Adriaan M."' showing total 19 results
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19 results on '"Den Berg, Adriaan M."'

1. 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

2. High-precision (p,t) reactions to determine reaction rates in the stellar rp-process

Author

Berg, G. P. A., Fujita, Y., Tatsuya Adachi, Den Berg, Adriaan M., Fujita, K., Fujita, H., Görres, J., Muhsin N. Harakeh, Hatanaka, K., Matic, A., Brien, S. O., Sakemi, Y., Shimbara, Y., Shimizu, Y., Talwar, R., Tameshige, Y., Tamii, A., Wakasa, T., Wiescher, M., Yosoi, M., KVI - Center for Advanced Radiation Technology, and Research unit Astroparticle Physics

Published
2010

6. Gamow-teller strengths of the inverse beta transition 176Yb--176Lu for spectroscopy of proton-proton and other sub-MeV solar neutrinos

Author

Fujiwara, M., Akimune, H., Den Berg, Adriaan M., Cribier, M., Daito, I., Ejiri, H., Fujimura, H., Fujita, Y., Goodman, C. D., Hara, K., Muhsin N. Harakeh, Ihara, F., Ishikawa, T., Jänecke, J., Kawabata, T., Raghavan, R. S., Schwarz, K., Tanaka, M., Yamanaka, T., Yosoi, M., Zegers, R. G. T., KVI - Center for Advanced Radiation Technology, and Onderzoeksgroep Astrodeeltjes Fysica

Subjects
Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Phenomenology, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Discrete Gamow-Teller (GT) transitions, 176Yb-->176Lu at low excitation energies have been measured via the (3He,t) reaction at 450 MeV and at 0 degrees. For 176Yb, two low-lying states are observed, setting low thresholds Q(neutrino)=301 and 445 keV for neutrino capture. Capture rates estimated from the measured GT strengths, the simple two-state excitation structure, and the low Q(neutrino) in Yb--Lu indicate that Yb-based neutrino-detectors are well suited for a direct measurement of the complete sub-MeV solar electron-neutrino spectrum (including pp neutrinos) where definitive effects of flavor conversion are expected.

Published
2000

7. Search for isovector giant monopole resonances via the Pb(He-3,tp) reaction

Author

Rgt, Zegers, Den Berg, Adriaan M., Sytze Brandenburg, Frr, Fleurot, Fujiwara, M., Guillot, J., Vm, Hannen, Muhsin N. Harakeh, Laurent, H., Schaaf, K., Sy, Werf, Willis, A., Hw, Wilschut, KVI - Center for Advanced Radiation Technology, Research unit Astroparticle Physics, Damage and Repair in Cancer Development and Cancer Treatment (DARE), Institut de Physique Nucléaire d'Orsay (IPNO), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
NUCLEI, High Energy Physics::Lattice, HE-3,T REACTION, Nuclear Theory, EXCITATION, STRENGTH, CHARGE-EXCHANGE REACTIONS, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, INTERMEDIATE ENERGIES, DECAY
Abstract

The Pb-nat(He-3, tp) reaction at E(He-3) = 177 MeV was studied to identify 2hw isovector monopole strength in Bi isotopes. Monopole strength was found in the region -45 < Q < -30 MeV in the coincidence data. The cross section is compared with distorted-wave Born approximation calculations for non-spin-flip and spin-flip isovector monopole resonances. The observed spin-flip and non-spin-flip monopole strengths in the proton-decay channel amount to 20% of the respective non-energy-weighted sum rule.

Published
2000

8. FRAGMENTATION OF GAMOW-TELLER STRENGTH OBSERVED IN SN-117,SN-120(HE-3,T)SB-117,SB-120 CHARGE-EXCHANGE REACTIONS

Author

Janecke, J., Pham, K., DA ROBERTS, Stewart, D., Muhsin N. Harakeh, GPA BERG, CC FOSTER, JE LISANTTI, Sawafta, R., EJ STEPHENSON, Den Berg, Adriaan M., SY VANDERWERF, SE MURAVIEV, MH URIN, KVI - Center for Advanced Radiation Technology, and Research unit Astroparticle Physics

Subjects
T SPECTRA, STATES, DEPENDENCE, Nuclear Theory, ISOVECTOR GIANT-RESONANCES, WIDTH, DIPOLE RESONANCE, Nuclear Experiment, HE-3
Abstract

The (He-3,t) charge-exchange reaction has been studied at E(He-3) = 200 MeV and angles near 0-degrees on targets of Sn-117 and Sn-120. Fragmentation of the giant Gamow-Teller resonance into separate components of the particle-hole type has been observed in good agreement with theoretical predictions. These components are connected with what is usually referred to in the literature as direct-, core-polarization-, and back-spin-flip Gamow-Teller strength. The observed cross sections near theta = 0-degrees suggest contributions from the isovector spin-flip interaction as well as the isovector tensor interaction. A theoretically predicted configuration splitting of the main Gamow-Teller component into two components involving the 1h11/2 neutron orbital could not uniquely be identified. The data are compatible, though, with such a splitting since the observed widths of the main Gamow-Teller components in Sb-117 and Sb-120 exceed the predicted splittings.

Published
1993

9. STUDY OF TC-103 AND THE ONSET OF DEFORMATION AROUND N = 60

Author

Degelder, P., Defrenne, D., Heyde, K., Kaffrell, N., Den Berg, Adriaan M., Blasi, N., Muhsin N. Harakeh, WA STERRENBURG, KVI - Center for Advanced Radiation Technology, and Research unit Astroparticle Physics

Published
1983

10. Overtones of isoscalar giant resonances studied in direct particle decay measurements

Author

Mátyás Hunyadi, Den Berg, Adriaan M., Csatlos, M., Csige, L., Davids, B., Garg, U., Gulyas, J., Muhsin N. Harakeh, Ma, Huu, Krasznahorkay, A., Sohler, D., Hj, Wortche, Research unit Astroparticle Physics, and Research unit Nuclear & Hadron Physics

Subjects
Nuclear Theory, Astrophysics::Solar and Stellar Astrophysics, DIPOLE RESONANCE, Nuclear Experiment
Abstract

The isoscalar giant dipole resonance (ISGDR), which is the lowest-energy overtone mode of the isoscalar giant resonances, has been studied in some medium-heavy and heavy nuclei in coincidence measurements. The observation of the direct nucleon decay channels significantly helped to enhance giant resonance strengths with respect to the underlying background and continuum, which gave an indication for the existence of a new mode with L = 2 character, assumingly the overtone of the ISGQR.

11. 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

12. Search for isovector giant monopole resonances via the Pb (^{3}He,tp) reaction

Author

Zegers, R. G. T., Den Berg, Adriaan M., Sytze Brandenburg, Fleurot, F., Fujiwara, M., Guillot, J., Hannen, V. M., Muhsin N. Harakeh, Laurent, H., Schaaf, K., Werf, S. Y., Willis, A., Wilschut, H. W. E. M., KVI - Center for Advanced Radiation Technology, Onderzoeksgroep Astrodeeltjes Fysica, and Damage and Repair in Cancer Development and Cancer Treatment - 1

13. 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

14. 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

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

Author

Ellinghaus, F., Bassini, R., Baumer, C., Den Berg, Adriaan M., Frekers, D., Frenne, D., Hagemann, M., Vm, Hannen, Muhsin N. Harakeh, Hartig, M., Heyse, J., Ma, Huu, Jacobs, E., Mielke, M., Schippers, Jacobus M., Schmidt, R., Sy, Werf, Hj, Wortche, KVI - Center for Advanced Radiation Technology, and Research unit Astroparticle Physics

Subjects
SPIN-ISOSPIN EXCITATION, ENERGY-LEVELS, NUCLEI, track reconstruction, HE-2, magnetic spectrometer, Di-proton detection
Abstract

At intermediate energies, the (d, He-2) charge-exchange reaction can be used to observe Gamow-Teller strength in the direction. He-2 denotes the two-proton system being in the singlet S-1(0) state. In the present experiment the two protons, which in the laboratory frame are emitted into the forward direction, have been momentum analyzed and detected in coincidence by the same spectrometer and detector. Protons from deuteron breakup processes can induce a large accidental coincidence background because of the much larger breakup cross-section as compared to the (d, He-2) cross-section. Nevertheless, background-free He-2 spectra with a resolution of 145 keV at an incident energy of 170 MeV are obtained, allowing the identification of many levels with high precision in the residual nuclei. The essential features of the detection system and the data-acquisition and analysis techniques which make our (d 2 He) experiments possible are described. Two nuclei, C-12 and Mg-24, have been used as a test case. (C) 2002 Elsevier Science B.V. All rights reserved.

16. Isospin and spin-isospin modes in nuclei

Author

Zegers, R. G. T., Den Berg, Adriaan M., Sytze Brandenburg, Fleurot, F. R. R., Hannen, V. M., Muhsin N. Harakeh, Schaaf, K., Werf, S. Y., Wilschut, H. W., Guillot, J., Laurent, H., Willis, A., Janecke, J., Fujiwara, M., Toki, H., Kishimoto, T., Hatanaka, K., Takahisa, K., Research unit Nuclear & Hadron Physics, and Damage and Repair in Cancer Development and Cancer Treatment (DARE)

17. NON-SPIN-FLIP (HE-3, T) CHARGE-EXCHANGE AND ISOBARIC ANALOG STATES OF ACTINIDE NUCLEI STUDIED AT THETA=0-DEGREES, E(HE-3)=76 MEV AND 200 MEV

Author

Janecke, J., FD BECCHETTI, Den Berg, Adriaan M., GPA BERG, MB GREENFIELD, Muhsin N. Harakeh, MA HOFSTEE, Nadasen, A., DA ROBERTS, Sawafta, R., Schippers, Jacobus M., EJ STEPHENSON, DP STEWART, SY VANDERWERF, KVI - Center for Advanced Radiation Technology, and Research unit Astroparticle Physics

Subjects
SN-120, TA, W, AU-197, PB-208, TH-230, TH-232, U-234, U-238, PU-244, MONOPOLE RESONANCE, Nuclear Theory, MEASURED PROTON DECAY FROM IAS, THETA(ET, EP, THETA-T, MEASURED SIGMA(THETA-T) FOR ISOBARIC ANALOG STATE (IAS), OF IAS, PB-208, PA-230, PA-232, NP-234, NP-236, NP-238, AM-244, MEASURED SIGMA (ET) THETA=0-DEGREES, TH-230, TH-232, U-234, U-236, U-238 (HE-3,TP), E=76.5 MEV, ENRICHED AND LONG-LIVED RADIOACTIVE TARGETS, DEPENDENCE, SN-120 (HE-3,T), E=200 MEV, ISOVECTOR GIANT-RESONANCES, EFFECTIVE INTERACTION V-TAU FOR NON-SPIN-FLIP CHARGE EXCHANGE, THETA-P) FOR THETA-T=0-DEGREES, THETA-P=+120-DEGREES, +150, Nuclear Experiment, THETA-T=0-DEGREES TO 16-DEGREES, = 0-DEGREES, DEDUCED Q-VALUES FOR TRANSITIONS TO IAS, NB-90, SB-117, SN-120, (HE-3,T), E=200 MEV, C-12, O-16, AL-27, SI-28, TA, TH-230, TH-232, U-234, U-236, U-238, TRANSITIONS TO IAS, P-30, NB-90, SN-120, PB-208, GAMMA, ESCAPE WIDTHS GAMMA-UP, SPREADING WIDTHS GAMMA-DOWN, MODEL, PROBABILITY, LIGHT, (HE-3,T), E=76.5 MEV C-12, C-13, O-16, F-19, SI-28, ZR-90, SN-117, COULOMB DISPLACEMENT ENERGIES, W-181, RE-184, HG-197, PB-208, PA-230, PA-232, NP-234, NP-236, MAGNETIC SPECTROMETERS, DEGREES, -150-DEGREES, NP-238, AM-244, COULOMB DISPLACEMENT ENERGIES, TOTAL WIDTHS, INTERMEDIATE ENERGIES, DECAY
Abstract

The (He-3, t) charge-exchange reaction has been studied at theta = 0-degree-C and bombarding energies of E(He-3) = 76.5 MeV and 200 MeV. Spectra were measured using magnetic analysis for target nuclei of C-12, C-13, O-16, F-19, Si-28, Si-29, Si-30, Zr-90, Sn-117, Sn-120, (nat)Ta, (nat)W, Au-197, Pb-208, Th-230, Th-232, U-234, U-236, U-238 and Pu-244. The measurements at 76.5 MeV concentrated on the isobaric analog states of several actinide nuclei, particularly on their widths and the branching ratios for proton decay. Cross sections, Q-values and total widths were determined for the transitions to the isobaric analog states. Coulomb displacement energies derived from the measured Q-values display the influence of deformed nuclear shapes. Escape widths GAMMA-up and spreding widths GAMMA-down of the isobaric analog states in five actinide nuclei were deduced from the measured proton-decay branching ratios. They were found to be in agreement with predictions which postulate isospin mixing via the Coulomb force with the (T0-1)-component of the isovector giant monopole resonance. The measurements at 200 MeV were concerned with transitions to isobaric analog states in both light and heavy nuclei, including several actinide nuclei, but Gamow-Teller resonances and transitions to numerous other states were also observed. The measured cross sections for several transitions to isobaric analog states from Si-30 to Pb-208 were used to extract the effective interaction V(tau) for non-spin-flip (He-3, t) charge exchange at E(He-3) almost-equal-to 200 MeV. The interaction strength V(tau) decreases by a factor 0.6 when compared to previously measured values for the energy range E(He-3) = 65 to 90 MeV. An angular distribution from theta(t) = 0-degree to 16-degrees for the transition to the isobaric analog state in Sb-120 measured at E(He-3) = 200 MeV was found to be in very good agreement with microscopic calculations.

18. The (t,3He) and (3He, t) reactions as probes of Gamow-Teller strength

Author

Zegers, R. G. T., Akimune, H., Austin, S. M., Bazin, D., Den Berg, Adriaan M., Berg, G. P. A., Brown, B. A., Brown, J., Cole, A. L., Daito, I., Fujita, Y., Fujiwara, M., Gales, S., Muhsin N. Harakeh, Hashimoto, H., Hayami, R., Hitt, G. W., Howard, M., Itoh, M., Jänecke, J., Kawabata, T., Kawase, K., Kinoshita, M., Nakamura, T., Nakanishi, K., Nakayama, S., Okumura, S., Richter, W. A., Roberts, D. A., Sherrill, B. M., Shimbara, Y., Steiner, M., Uchida, M., Ueno, H., Yamagata, T., Yosoi, M., KVI - Center for Advanced Radiation Technology, and Onderzoeksgroep Astrodeeltjes Fysica

19. Excitation of the isovector giant monopole resonances via the Pb-nat(He-3,tp) reaction

Author

Rgt, Zegers, Den Berg, Adriaan M., Sytze Brandenburg, Fujiwara, M., Guillot, J., Muhsin N. Harakeh, Laurent, H., Sy, Werf, Willis, A., Hw, Wilschut, KVI - Center for Advanced Radiation Technology, Research unit Astroparticle Physics, and Damage and Repair in Cancer Development and Cancer Treatment (DARE)

Subjects
SPIN, NUCLEI, HE-3,T REACTION, Nuclear Theory, STRENGTH, SCATTERING, GAMOW-TELLER RESONANCE, CHARGE-EXCHANGE REACTIONS, FRAGMENTATION, Nuclear Experiment, INTERMEDIATE ENERGIES, DECAY
Abstract

The Pb-nat(He-3,t) reaction and the subsequent decay of the excited nucleus by proton emission at backward angles were studied at E(He-3) = 177 MeV with the aim to separate the 2 (h) over bar omega isovector monopole strength in Bi isotopes from the continuum background. Since the continuum is largely due to quasifree processes associated with forward-peaked high-energy protons, the observed resonance-to-continuum ratio is drastically improved when coincidences between ejectile tritons and protons emitted at backward angles are required. Furthermore, the cross section for the monopole resonances excited via (He-3,t) is, unlike the cross sections for higher multipolarity excitations, strongly forward peaked. By comparing coincidence spectra at theta (t)approximate to0 degrees and at finite angles. monopole strength was found in the region -45

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