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15 results on '"Mücher, Dennis"'

1. Comprehensive test of nuclear level density models

Author

Goriely, Stephane, Larsen, Ann-Cecilie, and Mücher, Dennis

Subjects
Nuclear Theory
Abstract

For the last two decades, experimental information on nuclear level densities for about 60 different nuclei has been obtained on the basis of the Oslo method. While each of these measurements has been typically compared to one or a few level density models, a global study including all the measurements has been missing. The present study provides a systematic comparison between Oslo data and six global level density models for 42 nuclei for which $s$-wave resonance spacings are also available. We apply a coherent normalization procedure to the Oslo data for each of the six different models, all being treated on the same footing. Our quantitative analysis shows that the constant-temperature model presents the best global description of the Oslo data, closely followed by the mean-field plus combinatorial model and Hartree-Fock plus statistical model. Their accuracies are quite similar, so that it remains difficult to clearly favour one of these models. When considering energies above the threshold where the experimental level scheme is complete, all the six models are shown to lead to rather similar accuracies with respect to Oslo data. The recently proposed shape method can, in principle, improve the situation since it provides an absolute estimate of the excitation-energy dependence of the measured level densities. We show for the specific case of $^{112}$Cd that the shape method could exclude the Hartree-Fock plus statistical model. Such an analysis remains to be performed for the bulk of data for which the shape method can be applied to the Oslo measurements before drawing conclusions on the general quality of a given nuclear level density model., Comment: 11 pages, 7 figures, published in PRC

Published
2023
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2. Intra- and Inter-Fraction Relative Range Verification in Heavy-Ion Therapy Using Filtered Interaction Vertex Imaging

Author

Hymers, Devin, Kasanda, Eva, Bildstein, Vinzenz, Easter, Joelle, Richard, Andrea, Spyrou, Artemis, Höhr, Cornelia, and Mücher, Dennis

Subjects
Physics - Medical Physics
Abstract

Heavy-ion therapy, particularly using scanned (active) beam delivery, provides a precise and highly conformal dose distribution, with maximum dose deposition for each pencil beam at its endpoint (Bragg peak), and low entrance and exit dose. To take full advantage of this precision, robust range verification methods are required; these methods ensure that the Bragg peak is positioned correctly in the patient and the dose is delivered as prescribed. Relative range verification allows intra-fraction monitoring of Bragg peak spacing to ensure full coverage with each fraction, as well as inter-fraction monitoring to ensure all fractions are delivered consistently. To validate the proposed filtered Interaction Vertex Imaging method for relative range verification, a ${}^{16}$O beam was used to deliver 12 Bragg peak positions in a 40 mm poly-(methyl methacrylate) phantom. Secondary particles produced in the phantom were monitored using position-sensitive silicon detectors. Events recorded on these detectors, along with a measurement of the treatment beam axis, were used to reconstruct the sites of origin of these secondary particles in the phantom. The distal edge of the depth distribution of these reconstructed points was determined with logistic fits, and the translation in depth required to minimize the $\chi^2$ statistic between these fits was used to compute the range shift between any two Bragg peak positions. In all cases, the range shift was determined with sub-millimeter precision, to a standard deviation of the mean of 220(10) $\mu$m. This result validates filtered Interaction Vertex Imaging as a reliable relative range verification method, which should be capable of monitoring each energy step in each fraction of a scanned heavy-ion treatment plan., Comment: 29 pages, 12 figures. Accepted version: Clarified language throughout, added summary of recent related clinical work, added detail on detection & reconstruction systems, added explicit evaluation of detection system, replaced comparison to simulation with comparison to prior studies, extended discussion of clinical applicability. Results & conclusions on range verification performance unchanged

Published
2021
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3. GEANT4 simulation of a new range verification method using delayed gamma spectroscopy of a Mo-92 marker

Author

Kasanda, Eva, Burbadge, Christine, Bildstein, Vinzenz, Turko, Josef, Spyrou, Artemis, Höhr, Cornelia, and Mücher, Dennis

Subjects
Physics - Medical Physics
Abstract

In this work, we propose a novel technique for in-vivo proton therapy range verification. This technique makes use of a small hadron tumour marker, $^{92}$Mo, implanted at a short known distance from the clinical treatment volume. Signals emitted from the marker during treatment can provide a direct measurement of the proton beam energy at the marker's position. Fusion-evaporation reactions between the proton beam and marker nucleus result in the emission of delayed characteristic $\gamma$ rays, which are detected off-beam for an improved signal-to-noise ratio. In order to determine the viability of this technique and to establish an experimental setup for future work, the Monte Carlo package GEANT4 was used in combination with ROOT to simulate a treatment scenario with the new method outlined in this work. These simulations show that analyzing the intensity of delayed $\gamma$ rays produced from competing reactions yields a precise measurement of the range of the proton beam relative to the marker, with sub-millimeter uncertainty.

Published
2020
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6. A new Time-of-flight detector for the R$$^3$$B setup

Author

Heil, M., Kelić-Heil, A., Bott, L., Almusidi, T., Alvarez-Pol, H., Atar, L., Atkins, L., Aumann, T., Benlliure, J., Boretzky, K., Brückner, B., Cabanelas, P., Caesar, C., Casarejos, E., Cederkall, J., Chulkov, L., Corsi, A., Dueñas, J., Erbacher, P., Rodriguez, S. Escribano, Falduto, A., Feijoo, M., Frotscher, A., Frühauf, J., Gašparić, I., Borge, M. J. G., Gerbig, J., Gernhäuser, R., Gilbert, M., Glorius, J., Gnoffo, B., Göbel, K., Caamaño, D. Gonzalez, Grein, A., Hartig, A.-L., Heggen, H., Heine, M., Heinz, A., Holl, M., Homm, I., Horvat, A., Johansson, H. T., Jonson, B., Kalantar-Nayestanaki, N., Kamenyero, A., Khodaparast, A., Kiselev, O., Klenze, P., Knösel, M., Koch, K., Körper, D., Kröll, T., Kurtulgil, D., Kurz, N., Löher, B., Langer, C., Lehr, C., Litvinov, Y., Liu, H., Morales, S. Murillo, Nácher, E., Nilsson, T., Park, J., Paschalis, S., Pellegri, L., Perea, A., Petri, M., Pohl, T., Ponnath, L., Popočovski, R., Reifarth, R., Rhee, H.-B., Sanchez, J. L. Rodriguez, Rossi, D., Sürder, C., Sánchez-Benítez, A. M., Savran, D., Scheit, H., Simon, H., Slavkovská, Z., Storck-Dutine, S., Sun, Y., Törnqvist, H. T., Tanaka, J., Tengblad, O., Thomas, B., Varga, L., Volknandt, M., Wagner, V., Wamers, F., Zanetti, L., Aliotta, Marialuisa, Alkhazov, Georgy, Almusidi, Tahani, Alvarez-Pol, Hector, André, Paul, Assié, Marlène, Atar, Leyla, Atkins, Liam, Audouin, Laurent, Aumann, Thomas, Authelet, Gilles, Ayyad, Yassid, Bajzek, Martin, Barriere, Antoine, Beceiro-Novo, Saul, Belogurov, Sergey, Bemmerer, Daniel, Benlliure, Jose, Bertulani, Carlos, Bezbakh, Andrey, Blanchon, Guillaume, Boos, Carl Georg, Boretzky, Konstanze, Borge, Maria J., Borzov, Ivan, Bott, Lukas, Brückner, Benjamin, Cabanelas Eiras, Pablo, Caesar, Christoph, Calinescu, Stefana, Casarejos, Enrique, Catford, Wilton, Cederkall, Joakim, Chatillon, Audrey, Cherciu, Madalin Ilie, Chishti, M Majid Rauf, Chulkov, Leonid, Cirstian, Andreea, Corsi, Anna, Cortina-Gil, Dolores, Cravo, Edgar, Crespo, Raquel, Danilov, Andrey, de Angelis, Giacomo, De Filippo, Enrico, Diaz-Torres, Alexis, Dickel, Timo, Dobrovolsky, Alexander, Doornenbal, Pieter, Duer, Meytal, Egelhof, Peter, Elekes, Zoltan, Enders, Joachim, Erbacher, Philipp, Escribano Rodriguez, Sonia, Fahlander, Claes, Falduto, Ashton, Feijoo, Martina, Fernandez Ruiz, Daniel, Fomichev, Andrey, Fulop, Zsolt, Galaviz Redondo, Daniel, Galiana, Elisabet, García, Gabriel, García Távora, Vicente, Gasparic, Igor, Ge, Zhuang, Geissel, Hans, Geraci, Elena, Gerl, Jürgen, Gernhäuser, Roman, Gillibert, Alain, Glorius, Jan, Gnoffo, Brunilde, Göbel, Kathrin, Golovkov, Mikhail, Golovtsov, Victor, Golubev, Pavel, González Caamaño, David, Gorshkov, Alexander, Graña González, Antia, Gridnev, Anatoly, Gruzinskii, Nikolai, Guimaraes, Valdir, Harakeh, Muhsin N., Hartig, Anna-Lena, Heftrich, Tanja, Heggen, Henning, Heil, Michael, Heinz, Andreas, Hen, Or, Henrich, Corinna, Henriques, Ana, Hensel, Thomas, Holl, Matthias, Homm, Ilja, Horvat, Andrea, Horváth, Ákos, Hucka, Jan-Paul, Inglessi, Alexander, Jedele, Andrea, Jelavic Malenica, Desa, Jenegger, Tobias, Ji, Liancheng, Johansson, Håkan, Jonson, Björn, Jurado, Beatriz, Kahlbow, Julian, Kalantar-Nayestanaki, Nasser, Kamenyero, Armel, Kazantseva, Erika, Kelic-Heil, Aleksandra, Khanzadeev, Alexey, Kiselev, Oleg, Klenze, Philipp, Knyazev, Alexander, Koch, Karsten, Kogimtzis, Moschos, Kokubun, Kei, Korolev, Guerman, Körper, Daniel, Korsheninnikov, Alexey, Korten, Wolfram, Kozlenko, Nikolai, Krasilovskaja, Sabina, Kresan, Dmytro, Krivshich, Anatoly, Kröll, Thorsten, Krupko, Sergey, Kudaibergenova, Eleonora, Kunne Sohler, Dorottya, Kurtulgil, Deniz, Kurz, Nikolaus, Kuzmin, Evgeny, Kuznetsov, Viacheslav, Labiche, Marc, Lagni, Andrea, Langer, Christoph, Lányi, Zsombor, Lazarus, Ian, Le Fèvre, Arnaud, Leifels, Yvonne, Lepine-Szily, Alinka, Lewitowicz, Marek, Lihtar, Ivana, Linh, Bui, Litvinov, Yuri, Liu, Hongna, Löher, Bastian, Lommel, Bettina, Lorenz, Enis, Lukasik, Jerzy, Macchiavelli, Augusto, Maev, Evgeny, Maillertet, Charles, Maisuzenko, Dmitrii, Maj, Adam, Martorana, Nunzia Simona, Mauss, Benoît, Mayri, Christophe, Milhomens da Fonseca, Leandro, Morfouace, Pierre, Mozumdar, Nikhil, Mücher, Dennis, Murillo Morales, Silvia, Nacher, Enrique, Nikolskii, Evgenii, Nilsson, Thomas, Nociforo, Chiara, Nolden, Fritz, Nyman, Göran, Obertelli, Alexandre, Pagano, Emanuele Vincenzo, Panin, Valerii, Park, Joochun, Paschalis, Stefanos, Pei, Junchen, Perea, Angel, Petri, Marina, Piasetzky, Eli, Pietri, Stephane, Pirrone, Sara, Politi, Giuseppe, Pollacco, Emauel, Ponnath, Lukas, Potlog, Petru-Mihai, Prajapat, Rinku, Pritula, Roman, Qi, Hang, Rappold, Christophe, Reifarth, Rene, Revel, Aldric, Rhee, Han-Bum, Risitano, Fabio, Rodriguez Sanchez, Jose Luis, Rose, Luke, Rossi, Dominic, Rudigier, Matthias, Russotto, Paolo, Sánchez-Benítez, Ángel-Miguel, Sanjari, Shahab, Santamaria, Clementine, Sarantsev, Victor, Savran, Deniz, Scheidenberger, Christoph, Scheit, Heiko, Schmidt, Konrad, Simon, Haik, Simon, Johannes, Slavkovská, Zuzana, Slepnev, Roman, Sorlin, Olivier, Sousa, Tomás, Spiridon, Alexandra, Stan, Emil, Stanoiu, Mihai, Stefanescu, Alexandra, Stefanescu, Ionut, Storck-Dutine, Sonja, Stott, Aaron, Sun, Baohua, Sun, Yelei, Sürder, Christian, Taieb, Julien, Tanaka, Junki, Tanihata, Isao, Taniuchi, Ryo, Tengblad, Olof, Terekhin, Pavel, Teubig, Pamela, Törnqvist, Hans, Trache, Livius, Trautmann, Wolfgang, Trimarchi, Marina, Typel, Stefan, Uesaka, Tomohiro, Unsworth, Carl, Uvarov, Lev, Vandebrouck, Marine, Varga, Laszlo, Velardita, Simone, Velho, Paulo, Vencelj, Matjaz, Volknandt, Meiko, Volkov, Sergei, von Tresckow, Martin, Wagner, Andreas, Wamers, Felix, Wang, Yanzhao, Whitehead, Matthew, Wienholtz, Frank, Wimmer, Kathrin, Winkler, Martin, Xarepe, Manuel, Ye, Yanlin, Zacarias, Sabrina, Zamora Cardona, Juan Carlos, Zhang, Wei, Zhdanov, Andrei, Zhukov, Mikhail, Zilges, Andreas, Zuber, Kai, Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-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), R3B, Federal Ministry of Education and Research (Germany), Helmholtz International Center for FAIR, Ministerio de Ciencia e Innovación (España), Xunta de Galicia, Agencia Estatal de Investigación (España), Swedish Research Council, Science and Technology Facilities Council (UK), Royal Society (UK), Projekt DEAL, Energy and Sustainability Research Institute Groni, and Nuclear Energy

Subjects
Nuclear and High Energy Physics, ddc:530, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det]
Abstract

19 pags., 16 figs., 8 tabs., We present the design, prototype developments and test results of the new time-of-flight detector (ToFD) which is part of the R3B experimental setup at GSI and FAIR, Darmstadt, Germany. The ToFD detector is able to detect heavy-ion residues of all charges at relativistic energies with a relative energy precision σΔE/ ΔE of up to 1% and a time precision of up to 14 ps (sigma). Together with an elaborate particle-tracking system, the full identification of relativistic ions from hydrogen up to uranium in mass and nuclear charge is possible., This work received support from BMBF (05P19RFFN1, 05P15RDFN1, 05P19RDFN1) and HIC for FAIR. J.P. has been supported by the Institute for Basic Science (IBS-R031-D1). E.C. has been supported by the Ministry of Science and Innovation in Spain (PGC2018-099746-B-C22). J.L.R.S. thanks the support from the Regional Government of Galicia under the program of postdoctoral fellowships ED481B-2017-002 and ED481D-2021-018. O.T. has been supported by AEI/FEDER, UE project No. PID2019-104390GB-I00. G.B., A.H., H.T.J., B.J. and T.N. have been supported by the Swedish Research Council under contract 2017-03839. This work was supported by the Royal Society and UK STFC awards ST/L005727/1, ST/P003885/1.

Published
2022

10. Determination of the $B(E3,0^+ \rightarrow 3^-)$ strength in the octupole-correlated nuclei $^{142,144}$Ba using Coulomb excitation

Author

Andreyev, Andrei, Barton, Charles, Blazhev, Andrey, Butler, Peter Anthony, Cederkäll, Joakim, Cline, Douglas, Cocolios, Thomas Elias, Danchev, Miroslav, Van Duppen, Piet, Gaffney, Liam Paul, Gernhäuser, Roman, Gladniski, Kalinin, Görgen, Andreas, Grahn, Tuomas, Greenlees, Paul, Guttormsen, Magne, Hadynska-Klek, Kasia, Herzberg, Rolf-Dietmar, Huyse, Mark, Ignatov, Alexander, Iwanicki, Jendrek, Jenkins, David, Jolie, Jan, Julin, Rauno, Jungclaus, Andrea, Joss, David Thomas, Kröll, Thorsten, Larsen, Ann-Cecille, Mücher, Dennis, Napiorkowski, Pawel, O’Neill, George Ghengis, Page, Robert, Pakarinen, Janne, Rahkila, Panu, Rainovski, Georgi, Reiter, Peter, Siem, Sunniva, Simpson, Gary, Thirolf, Peter, Thürauf, Michael, Wadsworth, Robert, Warr, Nigel, Wenander, Frederik, Wimmer, Katrin, Wrzosek-Lipska, Kasia, Wu, Ching-Yen, Yates, Steven, and Zielinska, Magdalena

Subjects
Detectors and Experimental Techniques
Published
2017

11. Determination of the $B(E3,0^+ \rightarrow 3^-)$ strength in the octupole-correlated nuclei $^{142,144}$Ba using Coulomb excitation

Author

Andreyev, Andrei, Barton, Charles, Blazhev, Andrey, Butler, Peter Anthony, Cederkäll, Joakim, Cline, Douglas, Cocolios, Thomas Elias, Danchev, Miroslav, Van Duppen, Piet, Gernhäuser, Roman, Görgen, Andreas, Grahn, Tuomas, Greenlees, Paul, Guttormsen, Magne, Jungclaus, Andrea, Hayes, Adam, Herzberg, Rolf-Dietmar, Huyse, Mark, Ignatov, Alexander, Ilieva, Tanja, Iwanicki, Jendrik, Jenkins, David, Jolie, Jan, Julin, Rauno, Kröll, Thorsten, Larsen, Ann-Cecillie, Mücher, Dennis, Napiorkowski, Pawel, O’Neill, Georg, Page, Robert, Pakarinen, Janne, Rahkila, Panu, Rainovski, Georgi, Reiter, Peter, Siem, Sunniva, Simpson, Gary, Thirolf, Peter, Thürauf, Michael, Wadsworth, Robert, Warr, Nigel, Wenander, Frederik, Wimmer, Katrin, Wrzosek-Lipska, Kasia, Wu, Ching-Yen, Yates, Steven, and Zielinska, Magdalena

Subjects
Detectors and Experimental Techniques
Published
2016

13. Studies of unbound states in isotopes at the N=8 shell closure

Author

Borge, Maria J G, Fraile, Luis M, Fynbo, Hans O U, Gernhäuser, Roman, Heinz, Andreas, Howard, Alan, Johansen, Jacob G, Johansson, Haakan T, Jonson, Björn, Kirsebom, Oliver S, Kröll, Thorsten, Lindberg, Simon, Mücher, Dennis, Nilsson, Thomas, Paschalis, Stefanos, Petri, Marina, Raabe, Riccardo, Riisager, Karsten, Tengblad, Olof, Thies, Ronja, and Van Duppen, Piet

Subjects
Detectors and Experimental Techniques
Published
2015

14. Dynamische Symmetrien von Atomkernen an Unterschalenabschlüssen

Author

Mücher, Dennis

Subjects
ddc:530
Abstract

In dieser Arbeit wurden die Einflüsse der Unterschalenabschlüsse bei Neutronenzahlen N=40 und N=56 auf die Kernstruktur der umliegenden Atomkerne untersucht. Der Schwerpunkt war hierbei der Kern 70Zn, der im Rahmen dieser Arbeit durch eine ganze Reihe von Experimenten untersucht wurde. Es wurde zunächst ein Photonenstreu-Experiment an der Universität Stuttgart durchgeführt, um die Lebensdauer des 2+2-Zustandes in 70Zn zu überprüfen. Des Weiteren wurde 70Zn mit monoenergetischen Neutronen an der University of Kentucky untersucht. Diese Messung konnte viele entscheidende Korrekturen im tiefenergetischen Termschema von 70Zn anbringen und zeigt generelle Probleme bei den bekannten experimentellen Daten der Zink-Isotope auf. Weiterhin wurden an der Yale University mit der Methode transienter Magnetfelder magnetische Momente kurzlebiger Zustände in 70Zn vermessen. Als Konsequenz dieser Resultate wurde in dieser Arbeit gezeigt, dass der Kern 70Zn durch einen F-Spin-symmetrischen IBM-2 -Hamiltonian in der dynamischen Symmetrie U(5) beschrieben werden kann. Es wurde eine neue Deutung für das ungewöhnliche energetische Verhalten der Zustände 0+2 und 2+3 gegeben. Für den Zustand 2+3 wurde dabei das Zerfallsverhalten als Signatur der Proton-Neutron gemischt-symmetrischen Anregung 2+1,ms gedeutet. Weiterhin wurden Kandidaten für gemischt-symmetrische Zustände höherer Phononenordnung vorgestellt. Hier konnten Effekte von starken Zustandsmischungen nachgewiesen werden. Das ungewöhnliche Verhalten der 2+1,ms-Zustände in den gerade-gerade Zink-Isotopen wurde als Brechung der F-Spin-Symmetrie beim Übergang in ein Isospin-symmetrisches System gedeutet. Es wurden ebenfalls Experimente mit radioaktiven Ionen-Strahlen der Kerne 88Kr und 92Kr vorgestellt um den aktuellen Stand der Entwicklung dieser Technik aufzuzeigen. Es wurde gezeigt, welche Aufgaben angegangen werden müssen, um in Zukunft die Spektroskopie gemischt-symmetrischer Anregungen mit radioaktiven Ionen-Strahlen möglich zu machen.

Published
2009

15. Investigation of High-Lying (α, γ) Resonances in \(^{22}Ne\) through One-Neutron Transfer in Inverse Kinematics at TIGRESS

Author

Greaves, Beau and Mücher, Dennis

Subjects
TIGRESS, Transfer Reaction, Inverse Kinematics, Nuclear Astrophysics, Gamma Spectroscopy, TRIUMF, 22Ne, Nuclear Physics
Abstract

Involved in the production of \(^{19}F\) and acting as a neutron source in the s-process in both asymptotic giant branch and massive stars, probing the properties of the resonance states for the \(^{18}O\)(α, γ)\(^{22}Ne\) reaction allows for a unique opportunity to limit the uncertainty in this reaction rate, as well as the resultant isotopic abundance for the fed and competing reactions. In November of 2018, a beam of \(^{21}Ne\) was delivered to a thin deuterated foil target to study the \(^{21}Ne\)(d,p)\(^{22}Ne\) reaction in ISAC II at TRIUMF. This was accomplished using the segmented germanium clover array, TIGRESS, alongside the segmented silicon array for measurement of recoil particles, SHARC. The measurement of these resonance states allowed for the determination of the spin of the 9.841 MeV resonance using the gamma-coincident proton angular distribution, the main source of reaction rate uncertainty present for the \(^{18}O\)(α, γ)\(^{22}Ne\) reaction below 0.1 GK.

Published
2019

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