When logged in, additional information is available in some parts of the website.

Publications by
Dr. Robert Grisenti

All publications of HI Jena

2020

T. Gassner, A. Gumberidze, M. Trassinelli, R. Heß, U. Spillmann, D. Banaś, K.-H. Blumenhagen, F. Bosch, C. Brandau, W. Chen, C. Dimopoulou, E. Förster, R. Grisenti, S. Hagmann, P.-M. Hillenbrand, P. Indelicato, P. Jagodzinski, T. Kämpfer, M. Lestinsky, D. Liesen, Y. Litvinov, R. Lötzsch, B. Manil, R. Märtin, F. Nolden, N. Petridis, M. Sanjari, K. Schulze, M. Schwemlein, A. Simionovici, M. Steck, Th. Stöhlker, C. Szabo, S. Trotsenko, I. Uschmann, G. Weber, O. Wehrhan, N. Winckler, D. Winters, N. Winters, E. Ziegler, and H. Beyer
High-resolution wavelength-dispersive spectroscopy of K-shell transitions in hydrogen-like gold
X-Ray Spectrometry 49, 204 (2020)

Abstract: We present a measurement of K‐shell transitions in H‐like gold (Au78+) using specially developed transmission type crystal spectrometers combined with Ge(i) microstrip detectors. The experiment has been carried out at the Experimental Storage Ring at GSI in Darmstadt. This is a first high‐resolution wavelength‐dispersive measurement of a K‐shell transition in a high‐Z H‐like ion, thus representing an important milestone in this field. Ideas on possible future improvements are discussed as well.

2019

J. Polz, A. P. L. Robinson, A. Kalinin, G. A. Becker, R. Fraga, M. Hellwing, M. Hornung, S. Keppler, A. Kessler, D. Klöpfel, H. Liebetrau, F. Schorcht, J. Hein, M. Zepf, R. E. Grisenti, and M. C. Kaluza
Efficient Laser-Driven Proton Acceleration from a Cryogenic Solid Hydrogen Target
Scientific Reports 9, 16534 (2019)

Abstract: We report on the successful implementation and characterization of a cryogenic solid hydrogen target in experiments on high-power laser-driven proton acceleration. When irradiating a solid hydrogen filament of 10 mm diameter with 10-Terawatt laser pulses of 2.5 J energy, protons with kinetic energies in excess of 20?MeV exhibiting non-thermal features in their spectrum were observed. The protons were emitted into a large solid angle reaching a total conversion efficiency of several percent. Two-dimensional particle-in-cell simulations confirm our results indicating that the spectral modulations are caused by collisionless shocks launched from the surface of the the high-density filament into a low-density corona surrounding the target. The use of solid hydrogen targets may significantly improve the prospects of laser-accelerated proton pulses for future applications.

F. Ozturk, B. Akkus, D. Atanasov, H. Beyer, F. Bosch, D. Boutin, C. Brandau, P. Bühler, R. Cakirli, R. Chen, W. Chen, X. Chen, I. Dillmann, C. Dimopoulou, W. Enders, H. Essel, T. Faestermann, O. Forstner, B. Gao, H. Geissel, R. Gernhäuser, R. Grisenti, A. Gumberidze, S. Hagmann, T. Heftrich, M. Heil, M. Herdrich, P.-M. Hillenbrand, T. Izumikawa, P. Kienle, C. Klaushofer, C. Kleffner, C. Kozhuharov, R. Knöbel, O. Kovalenko, S. Kreim, T. Kühl, C. Lederer-Woods, M. Lestinsky, S. Litvinov, Y. Litvinov, Z. Liu, X. Ma, L. Maier, B. Mei, H. Miura, I. Mukha, A. Najafi, D. Nagae, T. Nishimura, C. Nociforo, F. Nolden, T. Ohtsubo, Y. Oktem, S. Omika, A. Ozawa, N. Petridis, J. Piotrowski, R. Reifarth, J. Rossbach, R. Sánchez, M. Sanjari, C. Scheidenberger, R. Sidhu, H. Simon, U. Spillmann, M. Steck, Th. Stöhlker, B. Sun, L. Susam, F. Suzaki, T. Suzuki, S. Torilov, C. Trageser, M. Trassinelli, S. Trotsenko, X. Tu, P. Walker, M. Wang, G. Weber, H. Weick, N. Winckler, D. Winters, P. Woods, T. Yamaguchi, X. Xu, X. Yan, J. Yang, Y. Yuan, Y. Zhang, and X. Zhou
New test of modulated electron capture decay of hydrogen-like ¹⁴²Pm ions: Precision measurement of purely exponential decay
Physics Letters B 797, 134800 (2019)

Abstract: An experiment addressing electron capture (EC) decay of hydrogen-like ¹⁴²Pm⁶⁰⁺ ions has been conducted at the experimental storage ring (ESR) at GSI. The decay appears to be purely exponential and no modulations were observed. Decay times for about 9000 individual EC decays have been measured by applying the single-ion decay spectroscopy method. Both visually and automatically analysed data can be described by a single exponential decay with decay constants of 0.0126(7) s⁻¹ for automatic analysis and 0.0141(7) s⁻¹ for manual analysis. If a modulation superimposed on the exponential decay curve is assumed, the best fit gives a modulation amplitude of merely 0.019(15), which is compatible with zero and by 4.9 standard deviations smaller than in the original observation which had an amplitude of 0.23(4).

A. Gumberidze, D. B. Thorn, A. Surzhykov, C. J. Fontes, B. Najjari, A. Voitkiv, S. Fritzsche, D. Banaś, H. F. Beyer, W. Chen, R. E. Grisenti, S. Hagmann, R. Hess, P.-M. Hillenbrand, P. Indelicato, C. Kozhuharov, M. Lestinsky, R. Märtin, N. Petridis, R. V. Popov, R. Schuch, U. Spillmann, S. Tashenov, S. Trotsenko, A. Warczak, G. Weber, W. Wen, D. F. A. Winters, N. Winters, Z. Yin, and Th. Stöhlker
Electron- and proton-impact excitation of heliumlike uranium in relativistic collisions
Physical Review A 99, 032706 (2019)

Abstract: We have studied the K-shell excitation of He-like uranium (U90+) in relativistic collisions with hydrogen and argon atoms. Performing measurements with different targets, as well as with different collision energies, enabled us to explore the proton- (nucleus-) impact excitation as well as the electron-impact excitation process for the heaviest He-like ion. The large fine-structure splitting in uranium allowed us to partially resolve excitation into different L-shell levels. State-of-the-art relativistic calculations which include excitation mechanisms due to the interaction with both protons (nucleus) and electrons are in good agreement with the experimental findings. Moreover, our experimental data clearly demonstrate the importance of including the generalized Breit interaction in the treatment of the electron-impact excitation process.

2018

T. Gassner, M. Trassinelli, R. Heß, U. Spillmann, D. Banas, K.-H. Blumenhagen, F. Bosch, C. Brandau, W. Chen, C. Dimopoulou, E. Förster, R. Grisenti, A. Gumberidze, S. Hagmann, P.-M. Hillenbrand, P. Indelicato, P. Jagodzinski, T. Kämpfer, Ch. Kozhuharov, M. Lestinsky, D. Liesen, Yu. A. Litvinov, R. Loetzsch, B. Manil, R. Märtin, F. Nolden, N. Petridis, M. S. Sanjari, K. Schulze, M. Schwemlein, A. Simionovici, M. Steck, Th. Stöhlker, C. I. Szabo, S. Trotsenko, I. Uschmann, G. Weber, O. Wehrhan, N. Winckler, D. Winters, N. Winters, E. Ziegler, and H. Beyer
Wavelength-dispersive spectroscopy in the hard x-ray regime of a heavy highly-charged ion: the 1s Lamb shift in hydrogen-like gold
New Journal of Physics 20, 073033 (2018)

Abstract: Accurate spectroscopy of highly-charged high-Z ions in a storage ring is demonstrated to be feasible by the use of specially adapted crystal optics. The method has been applied for the measurement of the is Lamb shift in hydrogen-like gold (Au78+) in a storage ring through spectroscopy of the Lyman x-rays. This measurement represents the first result obtained for a high-Z element using high-resolution wavelength-dispersive spectroscopy in the hard x-ray regime, paving the way for sensitivity to higher-order QED effects.

C. Goy, M. Potenza, S. Dedera, M. Tomut, E. Guillerm, A. Kalinin, K.-O. Voss, A. Schottelius, N. Petridis, A. Prosvetov, G. Tejeda, J. Fernández, C. Trautmann, F. Caupin, U. Glasmacher, and R. Grisenti
Shrinking of Rapidly Evaporating Water Microdroplets Reveals their Extreme Supercooling
Physical Review Letters 120, 015501 (2018)

Abstract: The fast evaporative cooling of micrometer-sized water droplets in a vacuum offers the appealing possibility to investigate supercooled water—below the melting point but still a liquid—at temperatures far beyond the state of the art. However, it is challenging to obtain a reliable value of the droplet temperature under such extreme experimental conditions. Here, the observation of morphology-dependent resonances in the Raman scattering from a train of perfectly uniform water droplets allows us to measure the variation in droplet size resulting from evaporative mass losses with an absolute precision of better than 0.2%. This finding proves crucial to an unambiguous determination of the droplet temperature. In particular, we find that a fraction of water droplets with an initial diameter of 6379±12  nm remain liquid down to 230.6±0.6  K. Our results question temperature estimates reported recently for larger supercooled water droplets and provide valuable information on the hydrogen-bond network in liquid water in the hard-to-access deeply supercooled regime.

2017

A. Gumberidze, C. Kozhuharov, R. Zhang, S. Trotsenko, Y. Kozhedub, R. DuBois, H. Beyer, K.-H. Blumenhagen, C. Brandau, A. Bräuning-Demian, W. Chen, O. Forstner, B. Gao, T. Gassner, R. Grisenti, S. Hagmann, P.-M. Hillenbrand, P. Indelicato, A. Kumar, M. Lestinsky, Yu. A. Litvinov, N. Petridis, D. Schury, U. Spillmann, C. Trageser, M. Trassinelli, X. Tu, and Th. Stöhlker
Impact parameter sensitive study of inner-shell atomic processes in the experimental storage ring
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 408, 27 (2017)

Abstract: In this work, we present a pilot experiment in the experimental storage ring (ESR) at GSI devoted to impact parameter sensitive studies of inner shell atomic processes for low-energy (heavy-) ion-atom collisions. The experiment was performed with bare and He-like xenon ions (Xe54+, Xe52+) colliding with neutral xenon gas atoms, resulting in a symmetric collision system. This choice of the projectile charge states was made in order to compare the effect of a filled K-shell with the empty one. The projectile and target X-rays have been measured at different observation angles for all impact parameters as well as for the impact parameter range of ∼35–70 fm.

2016

M. Lestinsky, V. Andrianov, B. Aurand, V. Bagnoud, D. Bernhardt, H. Beyer, S. Bishop, K. Blaum, A. Bleile, At. Borovik, F. Bosch, C. Bostock, C. Brandau, A. Bräuning-Demian, I. Bray, T. Davinson, B. Ebinger, A. Echler, P. Egelhof, A. Ehresmann, M. Engström, C. Enss, N. Ferreira, D. Fischer, A. Fleischmann, E. Förster, S. Fritzsche, R. Geithner, S. Geyer, J. Glorius, K. Göbel, O. Gorda, J. Goullon, P. Grabitz, R. Grisenti, A. Gumberidze, S. Hagmann, M. Heil, A. Heinz, F. Herfurth, R. Heß, P.-M. Hillenbrand, R. Hubele, P. Indelicato, A. Källberg, O. Kester, O. Kiselev, A. Knie, C. Kozhuharov, S. Kraft-Bermuth, T. Kühl, G. Lane, Y. Litvinov, D. Liesen, X. Ma, R. Märtin, R. Moshammer, A. Müller, S. Namba, P. Neumayer, T. Nilsson, W. Nörtershäuser, G. G. Paulus, N. Petridis, M. Reed, R. Reifarth, P. Reiß, J. Rothhardt, R. Sanchez, M. Sanjari, S. Schippers, H. Schmidt, D. Schneider, P. Scholz, R. Schuch, M. Schulz, V. Shabaev, A. Simonsson, J. Sjöholm, Ö. Skeppstedt, K. Sonnabend, U. Spillmann, K. Stiebing, M. Steck, T. Stöhlker, A. Surzhykov, S. Torilov, E. Träbert, M. Trassinelli, S. Trotsenko, X. Tu, I. Uschmann, P. Walker, G. Weber, D. Winters, P. Woods, H. Zhao, and Y. Zhang
Physics book: CRYRING@ESR
European Physical Journal Special Topics 225, 797 (2016)

Abstract: The exploration of the unique properties of stored and cooled beams of highly-charged ions as provided by heavy-ion storage rings has opened novel and fascinating research opportunities in the realm of atomic and nuclear physics research. Since the late 1980s, pioneering work has been performed at the CRYRING at Stockholm and at the Test Storage Ring (TSR) at Heidelberg. For the heaviest ions in the highest charge-states, a real quantum jump was achieved in the early 1990s by the commissioning of the Experimental Storage Ring (ESR) at GSI Helmholtzzentrum für Schwerionenforschung (GSI) in Darmstadt where challenging experiments on the electron dynamics in the strong field regime as well as nuclear physics studies on exotic nuclei and at the borderline to atomic physics were performed. Meanwhile also at Lanzhou a heavy-ion storage ring has been taken in operation, exploiting the unique research opportunities in particular for medium-heavy ions and exotic nuclei.

2015

N. Petridis, R. E. Grisenti, Y. A. Litvinov, and T. Stöhlker
Prototype internal target design for storage ring experiments
Physica Scripta 2015, 014051 (2015)

Abstract: The introduction of cryogenically cooled, few micrometer-sized nozzle geometries and an essential modification of the experimental storage ring (ESR) target station allowed for a reliable operation using low- Z gases at target area densities in the range of 10¹³--10¹⁴ cm−². Therefore, a remarkably versatile target source was established, enabling operation over the whole range of desired target gases (from H₂ to Xe) and area densities (~10¹⁰ to ~10¹⁴ cm−²). Moreover, the considerably smaller orifice diameter of the new target source enables a much more compact inlet chamber while, at the same time, maintaining the demanding vacuum requirements of a storage ring. A completely new inlet chamber design is presented here, which, besides the improvements regarding the achievable area densities, will feature a variable beam width down to 1 mm at the ion beam interaction region. This is of paramount importance with respect to the realization of high precision experiments, e.g. by reducing the inaccuracy of the observation angle causing the relativistic Doppler broadening. While being intended for the deployment at the future high energy storage ring within the SPARC collaboration, the new inlet chamber can also replace the current one at the ESR or serve as an internal target for CRYRING.

G. Weber, H. Bräuning, A. Surzhykov, C. Brandau, S. Fritzsche, S. Geyer, R. E. Grisenti, S. Hagmann, C. Hahn, R. Hess, S. Hess, C. Kozhuharov, M. Kühnel, R. Märtin, N. Petridis, U. Spillmann, S. Trotsenko, D. F. A. Winters, and Th. Stöhlker
Combined linear polarization and angular distribution measurements of x-rays for precise determination of multipole-mixing in characteristic transitions of high- Z systems
Journal of Physics B: Atomic, Molecular and Optical Physics 48, 144031 (2015)

Abstract: By applying novel-type position sensitive x-ray detectors as Compton polarimeters we recently performed a study of the linear polarization of Lyman-α₁ radiation following radiative electron capture into initially bare uranium ions. It was found that a model-independent determination of the ratio of the E1 and M2 transition amplitudes, and consequently of the corresponding transition rates, is feasible by combining the linear polarization data with a measurement of the angular distribution of the emitted radiation. In this work a detailed description of the underlying experimental technique for combined measurements of the linear polarization and the angular distribution of characteristic transitions in high-Z ions is presented. Special emphasis is given to the application of two, two-dimensional position-sensitive x-ray detectors for Compton polarimetry of hard x-rays. Moreover, we demonstrate the polarimeter efficiency of such detector systems can be significantly improved if events, where the charge is spread over neighboring segments, are reconstructed to be used in the polarization analysis.

A. Gumberidze, D. B. Thorn, C. J. Fontes, B. Najjari, H. L. Zhang, A. Surzhykov, A. Voitkiv, S. Fritzsche, D. Banaś, H. Beyer, W. Chen, R. D. DuBois, S. Geyer, R. E. Grisenti, S. Hagmann, M. Hegewald, S. Hess, C. Kozhuharov, R. Märtin, N. Petridis, R. Reuschl, A. Simon, U. Spillmann, M. Trassinelli, S. Trotsenko, G. Weber, D. F. A. Winters, N. Winters, D. Yu, and Th. Stöhlker
Ground-state excitation of heavy highly-charged ions
Journal of Physics B: Atomic, Molecular and Optical Physics 48, 144006 (2015)

Abstract: We have studied the excitation of H-like and He-like uranium (U^91+ and U^90+ ) in relativistic collisions with gaseous targets by observing the subsequent x-ray emission. The experiment was conducted at the ESR storage ring of the GSI accelerator facility in Darmstadt, Germany. The measurements were performed with a newly developed multi-phase target at different collision energies. This enabled us to explore the proton (nucleus) impact excitation as well as the electron impact excitation processes in the relativistic collisions. The large fine-structure splitting in uranium allowed us to unambiguously resolve excitation to different L-shell levels. Moreover, information about the population of different magnetic sublevels has been obtained via an angular differential study of the decay photons associated with the subsequent de-excitation process. The experimental results are compared with calculations performed within the relativistic framework including excitation mechanisms due to both protons (nucleus) and electrons.

H. F. Beyer, T. Gassner, M. Trassinelli, R. Heß, U. Spillmann, D. Banaś, K.-H. Blumenhagen, F. Bosch, C. Brandau, W. Chen, C. Dimopoulou, E. Förster, R. E. Grisenti, A. Gumberidze, S. Hagmann, P.-M. Hillenbrand, P. Indelicato, P. Jagodzinski, T. Kämpfer, C. Kozhuharov, M. Lestinsky, D. Liesen, Y. A. Litvinov, R. Loetzsch, B. Manil, R. Märtin, F. Nolden, N. Petridis, M. S. Sanjari, K. S. Schulze, M. Schwemlein, A. Simionovici, M. Steck, Th. Stöhlker, C. I. Szabo, S. Trotsenko, I. Uschmann, G. Weber, O. Wehrhan, N. Winckler, D. F. A. Winters, N. Winters, and E. Ziegler
Crystal optics for precision x-ray spectroscopy on highly charged ions—conception and proof
Journal of Physics B: Atomic, Molecular and Optical Physics 48, 144010 (2015)

Abstract: The experimental investigation of quantum-electrodydamic contributions to the binding energies of inner shells of highly charged heavy ions requires an accurate spectroscopy in the region of hard x-rays suitable at a limited source strength. For this purpose the focusing compensated asymmetric Laue crystal optics has been developed and a twin-spectrometer assembly has been built and commissioned at the experimental storage ring of the GSI Helmholtzzentrum Darmstadt. We characterize the crystal optics and demonstrate the usefulness of the instrumentation for accurate spectroscopy of both stationary and fast moving x-ray sources. The experimental procedures discussed here may also be applied for other spectroscopic studies where a transition from conventional germanium x-ray detectors to crystal spectrometers seems too demanding because of low source intensity.

G. Weber, M. Herdrich, R. DuBois, P.-M. Hillenbrand, H. Beyer, L. Bozyk, T. Gassner, R. Grisenti, S. Hagmann, Y. Litvinov, F. Nolden, N. Petridis, M. Sanjari, D. Winters, and Th. Stöhlker
Total projectile electron loss cross sections of U²⁸⁺ ions in collisions with gaseous targets ranging from hydrogen to krypton
Physical Review ST - Accelerators and Beams 18, 034403 (2015)

Abstract: Beam lifetimes of stored U^(28+) ions with kinetic energies of 30 and 50  MeV/u, respectively, were measured in the experimental storage ring of the GSI accelerator facility. By using the internal gas target station of the experimental storage ring, it was possible to obtain total projectile electron loss cross sections for collisions with several gaseous targets ranging from hydrogen to krypton from the beam lifetime data. The resulting experimental cross sections are compared to predictions by two theoretical approaches, namely the CTMC method and a combination of the DEPOSIT code and the RICODE program.

2013

Y. Litvinov, S. Bishop, K. Blaum, F. Bosch, C. Brandau, L. Chen, I. Dillmann, P. Egelhof, H. Geissel, R. Grisenti, S. Hagmann, M. Heil, A. Heinz, N. Kalantar-Nayestanaki, R. Knöbel, C. Kozhuharov, M. Lestinsky, X. Ma, T. Nilsson, F. Nolden, A. Ozawa, R. Raabe, M. Reed, R. Reifarth, M. Sanjari, D. Schneider, H. Simon, M. Steck, Th. Stöhlker, B. Sun, X. Tu, T. Uesaka, P. Walker, M. Wakasugi, H. Weick, N. Winckler, P. Woods, H. Xu, T. Yamaguchi, Y. Yamaguchi, and Y. Zhang
Nuclear physics experiments with ion storage rings
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 317, 603 (2013)

Abstract: In the last two decades a number of nuclear structure and astrophysics experiments were performed at heavy-ion storage rings employing unique experimental conditions offered by such machines. Furthermore, building on the experience gained at the two facilities presently in operation, several new storage ring projects were launched worldwide. This contribution is intended to provide a brief review of the fast growing field of nuclear structure and astrophysics research at storage rings.

A. Gumberidze, D. Thorn, C. Fontes, B. Najjari, H. Zhang, A. Surzhykov, A. Voitkiv, S. Fritzsche, D. Banaś, H. Beyer, W. Chen, R. DuBois, S. Geyer, R. Grisenti, S. Hagmann, M. Hegewald, S. Hess, C. Kozhuharov, R. Märtin, I. Orban, N. Petridis, R. Reuschl, A. Simon, U. Spillmann, M. Trassinelli, S. Trotsenko, G. Weber, D. Winters, N. Winters, D. Yu, and Th. Stöhlker
Electron- and Proton-Impact Excitation of Hydrogenlike Uranium in Relativistic Collisions
Physical Review Letters 110, 213201 (2013)

Abstract: The K shell excitation of H-like uranium (U91+) in relativistic collisions with different gaseous targets has been studied at the experimental storage ring at GSI Darmstadt. By performing measurements with different targets as well as with different collision energies, we were able to observe for the first time the effect of electron-impact excitation (EIE) process in the heaviest hydrogenlike ion. The large fine-structure splitting in H-like uranium allowed us to unambiguously resolve excitation into different L shell levels. State-of-the-art calculations performed within the relativistic framework which include excitation mechanisms due to both protons (nucleus) and electrons are in good agreement with the experimental findings. Moreover, our experimental data clearly demonstrate the importance of including the generalized Breit interaction in the treatment of the EIE process.

2012

P. Neumayer, B. Aurand, R. Fraga, B. Ecker, R. E. Grisenti, A. Gumberidze, D. C. Hochhaus, A. Kalinin, M. C. Kaluza, T. Kühl, J. Polz, R. Reuschl, Th. Stöhlker, D. Winters, N. Winters, and Z. Yin
Evidence for ultra-fast heating in intense-laser irradiated reduced-mass targets
Physics of Plasmas 19, 122708 (2012)

Abstract: We report on an experiment irradiating individual argon droplets of 20 μm diameter with laser pulses of several Joule energy at intensities of 10^{19} W/cm^{2}. K-shell emission spectroscopy was employed to determine the hot electron energy fraction and the time-integrated charge-state distribution. Spectral fitting indicates that bulk temperatures up to 160 eV are reached. Modelling of the hot-electron relaxation and generation of K-shell emission with collisional hot-electron stopping only is incompatible with the experimental results, and the data suggest an additional ultra-fast (sub-ps) heating contribution. For example, including resistive heating in the modelling yields a much better agreement with the observed final bulk temperature and qualitatively reproduces the observed charge state distribution.

M. Grieser, Yu. A. Litvinov, R. Raabe, K. Blaum, Y. Blumenfeld, P. A. Butler, F. Wenander, P. J. Woods, M. Aliotta, A. Andreyev, A. Artemyev, D. Atanasov, T. Aumann, D. Balabanski, A. Barzakh, L. Batist, A.-P. Bernardes, D. Bernhardt, J. Billowes, S. Bishop, M. Borge, I. Borzov, F. Bosch, A. J. Boston, C. Brandau, W. Catford, R. Catherall, J. Cederkall, D. Cullen, T. Davinson, I. Dillmann, C. Dimopoulou, G. Dracoulis, Ch. E. Düllmann, P. Egelhof, A. Estrade, D. Fischer, K. Flanagan, L. Fraile, M. A. Fraser, S. J. Freeman, H. Geissel, J. Gerl, P. Greenlees, R. E. Grisenti, D. Habs, R. von Hahn, S. Hagmann, M. Hausmann, J. J. He, M. Heil, M. Huyse, D. Jenkins, A. Jokinen, B. Jonson, D. T. Joss, Y. Kadi, N. Kalantar-Nayestanaki, B. P. Kay, O. Kiselev, H.-J. Kluge, M. Kowalska, C. Kozhuharov, S. Kreim, T. Kröll, J. Kurcewicz, M. Labiche, R. C. Lemmon, M. Lestinsky, G. Lotay, X. W. Ma, M. Marta, J. Meng, D. Mücher, I. Mukha, A. Müller, A. Murphy, G. Neyens, T. Nilsson, C. Nociforo, W. Nörtershäuser, R. D. Page, M. Pasini, N. Petridis, N. Pietralla, M. Pfützner, Z. Podolyak, P. Regan, M. W. Reed, R. Reifarth, P. Reiter, R. Repnow, K. Riisager, B. Rubio, M. S. Sanjari, D. W. Savin, C. Scheidenberger, S. Schippers, D. Schneider, R. Schuch, D. Schwalm, L. Schweikhard, D. Shubina, E. Siesling, H. Simon, J. Simpson, J. Smith, K. Sonnabend, M. Steck, T. Stora, Th. Stöhlker, B. Sun, A. Surzhykov, F. Suzaki, O. Tarasov, S. Trotsenko, X. L. Tu, P. Van Duppen, C. Volpe, D. Voulot, P. M. Walker, E. Wildner, N. Winckler, D. F. A. Winters, A. Wolf, H. S. Xu, A. Yakushev, T. Yamaguchi, Y. J. Yuan, Y. H. Zhang, and K. Zuber
Storage ring at HIE-ISOLDE Technical design report
European Journal of Physics - Special Topics 207, 1 (2012)

Abstract: We propose to install a storage ring at an ISOL-type radioactive beam facility for the first time. Specifically, we intend to setup the heavy-ion, low-energy ring TSR at the HIE-ISOLDE facility in CERN, Geneva. Such a facility will provide a capability for experiments with stored secondary beams that is unique in the world. The envisaged physics programme is rich and varied, spanning from investigations of nuclear ground-state properties and reaction studies of astrophysical relevance, to investigations with highly-charged ions and pure isomeric beams. The TSR might also be employed for removal of isobaric contaminants from stored ion beams and for systematic studies within the neutrino beam programme. In addition to experiments performed using beams recirculating within the ring, cooled beams can also be extracted and exploited by external spectrometers for high-precision measurements. The existing TSR, which is presently in operation at the Max-Planck Institute for Nuclear Physics in Heidelberg, is well-suited and can be employed for this purpose. The physics cases as well as technical details of the existing ring facility and of the beam and infrastructure requirements at HIE-ISOLDE are discussed in the present technical design report.

R. Fraga, A. Kalinin, M. Kühnel, D. C. Hochhaus, A. Schottelius, J. Polz, M. C. Kaluza, P. Neumayer, and R. E. Grisenti
Compact cryogenic source of periodic hydrogen and argon droplet beams for relativistic laser-plasma generation
Review of Scientific Instruments 83, 025102 (2012)

Abstract: We present a cryogenic source of periodic streams of micrometer-sized hydrogen and argon droplets as ideal mass-limited target systems for fundamental intense laser-driven plasma applications. The highly compact design combined with a high temporal and spatial droplet stability makes our injector ideally suited for experiments using state-of-the-art high-power lasers in which a precise synchronization between the laser pulses and the droplets is mandatory. We show this by irradiating argon droplets with multi-terawatt pulses.

2011

N. Petridis, A. Kalinin, U. Popp, V. Gostishchev, Y. Litvinov, C. Dimopoulou, F. Nolden, M. Steck, C. Kozhuharov, D. B. Thorn, A. Gumberidze, S. Trotsenko, S. Hagmann, U. Spillmann, D. F. A. Winters, R. Dörner, Th. Stöhlker, and R. E. Grisenti
Energy loss and cooling of relativistic highly charged uranium ions interacting with an internal hydrogen droplet target beam
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 656, 1 (2011)

Abstract: We present measurements of the energy loss of relativistic highly charged uranium ions interacting with a target beam of near-liquid density hydrogen droplets at the experimental storage ring (ESR) at GSI. Our results reveal that a liquid droplet target beam virtually behaves like a homogeneous gas jet target with respect to both energy loss and ion beam cooling. We also provide first results on ion beam cooling efficiency at high hydrogen area target densities, which are consistent with numerical estimations based on a simple model of the cooling force.

Th. Stöhlker, H. F. Beyer, A. Bräuning-Demian, C. Brandau, A. Gumberidze, R. E. Grisenti, S. Hagmann, F. Herfurth, Ch. Kozhuharov, Th. Kühl, D. Liesen, Yu. Litvinov, R. Märtin, W. Nörtershäuser, O. Kester, N. Petridis, W. Quint, U. Schramm, R. Schuch, U. Spillmann, S. Trotsenko, and G. Weber
SPARC: The Stored Particle Atomic Research Collaboration At FAIR
AIP Conference Proceedings 1336, 132 (2011)

Abstract: The future international accelerator Facility for Antiproton and Ion Research (FAIR) encompasses 4 scientific pillars containing at this time 14 approved technical proposals worked out by more than 2000 scientists from all over the world. They offer a wide range of new and challenging opportunities for atomic physics research in the realm of highly‐charged heavy ions and exotic nuclei. As one of the backbones of the Atomic, Plasma Physics and Applications (APPA) pillar, the Stored Particle Atomic Physics Research Collaboration (SPARC) has organized tasks and activities in various working groups for which we will present a concise survey on their current status.

D. B. Thorn, A. Gumberidze, S. Trotsenko, D. Banas, H. Beyer, C. J. Bostock, I. Bray, W. Chen, R. DuBois, C. J. Fontes, S. Fritzsche, D. V. Fursa, R. Grisenti, S. Geyer, S. Hagmann, S. Hess, M. Hegewald, C. Kozhuharov, R. Märtin, I. Orban, N. Petridis, R. Reuschl, A. Simon, U. Spillmann, A. Surzhykov, M. Trassinelli, G. Weber, D. F. A. Winters, N. Winters, H. L. Zhang, and Th. Stöhlker
Polarization and anisotropic emission of K-shell radiation from heavy few electron ions
Canadian Journal of Physics 89, 513 (2011)

Abstract: The population of magnetic sublevels in hydrogen-like uranium ions has been investigated in relativistic ion–atom collisions by observing the subsequent X-ray emission. Using the gas target at the experimental storage ring facility we observed the angular emission of Lyman-α radiation from hydrogen-like uranium ions. The alignment parameter for three different interaction energies was measured and found to agree well with theory. In addition, the use of different gas targets allowed for the electron-impact excitation process to be observed.