Newsletter November 2019
Dear colleagues and friends of the HI-Jena,
Welcome to the November issue of our newsletter.
Below you find informations about the latest news and activities of our institute
Helmholtz Institute Jena
Boosting quantum vacuum signatures by coherent harmonic focusing
In a recent publication , we showed that coherent harmonic focusing provides an efficient mechanism to boost all-optical signatures of quantum vacuum nonlinearity in the collision of high-intensity laser fields, thereby offering a promising route to their first experimental detection.
Assuming two laser pulses of given parameters at our disposal, we demonstrate a substantial increase of the number of signal photons measurable in experiments where one of the pulses undergoes coherent harmonic focusing before it collides with the fundamental-frequency pulse.
Imposing a quantitative criterion to discern the signal photons from the background of the driving laser photons and accounting for the finite purity of polarization filtering, we find that signal photons arising from inelastic scattering processes constitute a promising signature. By contrast, quasi-elastic contributions which are conventionally assumed to form the most prospective signal remain background dominated.
In our study we exemplify that the assessment of an advanced scheme, such as coherent harmonic focusing, necessarily requires the consideration of real-world limitations. For instance, we demonstrate that the mere existence of a non-vanishing polarization purity leads to a decisive change of perspective on the relevance of the CHF scheme.
Our findings may result in a paradigm shift concerning which photonic signatures of quantum vacuum nonlinearity are accessible in experiment. We are confident that they will stimulate many further theoretical ideas and proposals as well as dedicated experimental campaigns aiming at the first verification of quantum vacuum nonlinearity using coherent harmonic focusing and replications based on conventional higher-harmonic generation techniques
News and Announcements
Efficient Laser-Driven Proton Acceleration from a Cryogenic Solid Hydrogen Target
Using high-intensity laser pulses from the POLARIS system together with a cryogenically-cooled source of solid hydrogen, it could be shown that the efficiency of the energy conversion from the laser pulse to the proton beam can be enhanced significantly to several percent. With only 2.5 J laser energy on target, protons with kinetic energies in excess of 20 MeV could be produced. Furthermore, it was found that protons having the highest kinetic energies were accelerated by a combination of the standard target-normal sheath acceleration (TNSA) mechanism and the post-acceleration of these protons in a collisionless electro-static shock. These results show that laser-accelerated protons using a solid hydrogen jet as a target are a promising candidate for applications requiring a high-efficiency, high-energy proton source.
Reference: 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," Sci. Rep. 9, 16534 (2019).
7th Joint RS-APS & HGS-HIRe Lecture Week on Photon Imaging from the Optical to the XUV Regime
The 7th Joint HGS-HIRe and RS-APS Lecture Week on Atomic and Laser/Plasma Physics addressed the various photon imaging techniques available from the optical to the XUV regime. Hosted by the “Kloster Hardehausen” with its stimulating atmosphere, Christian Eggeling (FSU Jena), Tatiana Latychevskaia (PSI, Switzerland), Gerd Schneider (HZ Berlin), Silvio Fuchs (HI Jena) and the participating students discussed together various aspects of this crossdisciplinary topic.
Thanks to the enthusiasm of all participants and an impressive visit of Heinz Nixdorf museum (Paderborn) during our social activity, this event continues the very successful series of lecture weeks jointly organized by the Research School of Advanced Photon Science at the Helmholtz Institute Jena and the Helmholtz Graduate School for Hadron and Ion Research – the graduate school of GSI-FAIR. (gw)
Groundbreaking ceremony for extension of the Helmholtz Institute Jena
The structural extension of the Helmholtz Institute Jena (HI Jena) has begun, the ground-breaking ceremony has taken place. The new building, which will be erected in the immediate vicinity of the existing institute building, will create additional office, seminar and laboratory space. The groundbreaking ceremony is also an important starting signal for further fostering the successful growth of the Helmholtz Institute Jena, a branch of the GSI Helmholtzzentrum für Schwerionenforschung GmbH located on the campus of the Friedrich Schiller University (FSU) Jena.
After the welcome address by the Director of the Helmholtz Institute Jena, Professor Thomas Stöhlker, the Minister for Economy, Science and Digital Society of the State of Thuringia, Wolfgang Tiefensee, and the Minister for Infrastructure and Agriculture, Birgit Keller, passed on their greetings. On behalf of the GSI Helmholtzzentrum für Schwerionenforschung spoke Research Director Professor Karlheinz Langanke, and Professor Georg Pohnert, Vice President of Research, spoke on behalf of the Friedrich Schiller University Jena.
The Thuringian Ministry of Infrastructure had announced an architectural competition for the new research building. The winner was a regional office: The jury unanimously selected the design of the "Osterwold°Schmidt EXP!ANDER Architekten" office in Weimar, which had submitted the plans jointly with Impuls Landschaftsarchitektur Jena. The four-storey, cube-shaped building with a floor area of around 240 square meters connects to the target laboratory in the basement. As link to the existing institute building, an interlocking gate is planned.
The construction period for the new building, which will be erected on a slope on a federal state property within the university site, will be approximately two years. The state of Thuringia is financing the construction project and has scheduled eight million euros for it in its state budget.
With the additional institute building, the infrastructural conditions for cutting-edge research, which has been carried out at the HI Jena since the institute was founded ten years ago, will be further improved. The institute's research activities focus on the physics occurring at the border between conventional particle-acceleration technology and the fast-evolving field of laser-induced particle acceleration. The HI-Jena offers outstanding research in the field of coupling of intense photon fields and the supporting development of appropriate instrumentation. In addition, the Helmholtz Institute Jena will further expand and strengthen the close connection between the university and the large-scale research facility GSI with the international accelerator center FAIR, which is currently being built here.
Around 100 employees and associated scientists in ten working groups are currently working at the HI Jena. There is also an own research school (“Research School of Advanced Photon Science”) with around 60 doctoral students. In addition, the successful acquisition of third-party funding and regional networking – for example through cooperation and collaboration with the Fraunhofer Institute for Optics and Precision Engineering and the Leibniz Institute of Photonic Technology – have increased steadily. (BP)
Guests of the institute
From October 2019 to March 2020 Dr. Elena A. Mosman (Tomsk Polytechnic University, Tomsk, Russia) visits the HI Jena in the framework of the DAAD Michail-Lomonosov-Programm to collaborate on Strong Field Effects in Intense Laser Fields.
Seminar room HI-Jena, Fröbelstieg 3
Stochastic processes are highly relevant in research fields as different as neuroscience, economy, ecology, chemistry, and fundamental physics. However, due to their intrinsic unpredictability, stochastic mechanisms are very challenging for any kind of investigations and practical applications. I will report on the deliberate use of stochastic X-ray pulses in two-dimensional spectroscopy to the simultaneous mapping of unoccupied and occupied electronic states of atoms in a regime where the opacity and transparency properties of matter are subject to the incident intensity and photon energy. I will present formalism which enables investigations of the response of the electronic structure to irradiation with intense X-ray pulses while the time structure of the incident pulses is preserved.
Seminar room HI-Jena, Fröbelstieg 3
Opportunities for measurements of astrophysical-relevant alpha-capture reaction rates at CRYRING@ESR
O. Forstner, D. Bemmerer, T. Cowan, R. Dressler, A. Junghans, D. Schumann, T. Stöhlker, T. Szücs, A. Wagner, and K. Zuber
X-Ray Spec. 49, 129 (2020)
High-precision X-ray spectroscopy of Fe ions in an EBIT using a micro-calorimeter detector: First results
M. Herdrich, A. Fleischmann, D. Hengstler, S. Allgeier, C. Enss, S. Trotsenko, T. Morgenroth, R. Schuch, G. Weber, and T. Stöhlker
X-Ray Spec. 49, 184 (2020)
Efficient Laser-Driven Proton Acceleration from a Cryogenic Solid Hydrogen Target
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
Sci. Rep. 9, 16534 (2019)
g Factor of Lithiumlike Silicon: New Challenge to Bound-State QED
D. A. Glazov, F. Köhler-Langes, A. V. Volotka, K. Blaum, F. Heiße, G. Plunien, W. Quint, S. Rau, V. M. Shabaev, S. Sturm, and G. Werth
Phys. Rev. Lett. 123, 173001 (2019)
How to Observe the Vacuum Decay in Low-Energy Heavy-Ion Collisions
I. A. Maltsev, V. M. Shabaev, R. V. Popov, Y. S. Kozhedub, G. Plunien, X. Ma, T. Stöhlker, and D. A. Tumakov
Phys. Rev. Lett. 123, 113401 (2019)
Roadmap on photonic, electronic and atomic collision physics: III. Heavy particles: with zero to relativistic speeds
F. Aumayr, K. Ueda, E. Sokell, S. Schippers, H. Sadeghpour, F. Merkt, T. F. Gallagher, F. B. Dunning, P. Scheier, O. Echt, T. Kirchner, S. Fritzsche, A. Surzhykov, X. Ma, R. Rivarola, O. Fojon, L. Tribedi, E. Lamour, J. R. C. Lopez-Urrutia, Y. A. Litvinov, V. Shabaev, H. Cederquist, H. Zettergren, M. Schleberger, R. A. Wilhelm, T. Azuma, P. Boduch, H. T. Schmidt, and T. Stöhlker
J. Phys. B 52, 171003 (2019)
Properties of a cylindrical Penning trap with conical endcap openings
S. Kumar, W. Quint, S. Ringleb, C. P. Safvan, N. Stallkamp, T. Stöhlker, and M. Vogel
Phys. Scripta 94, 075401 (2019)
The hyperfine puzzle of strong-field bound-state QED
W. Nörtershäuser, J. Ullmann, L. V. Skripnikov, Z. Andelkovic, C. Brandau, A. Dax, W. Geithner, C. Geppert, C. Gorges, M. Hammen, V. Hannen, S. Kaufmann, K. König, F. Kraus, B. Kresse, Y. A. Litvinov, M. Lochmann, B. Maaß, J. Meisner, T. Murböck, A. F. Privalov, R. Sánchez, B. Scheibe, M. Schmidt, S. Schmidt, V. M. Shabaev, M. Steck, T. Stöhlker, R. C. Thompson, C. Trageser, M. Vogel, J. Vollbrecht, A. V. Volotka, and C. Weinheimer
Hyperfine Interact. 240, 51 (2019)
3.5 kW coherently combined ultrafast fiber laser
M. Müller, A. Klenke, A. Steinkopff, H. Stark, A. Tünnermann, and J. Limpert
Opt. Lett. 43, 6037 (2018)
Ultrafast thulium fiber laser system emitting more than 1 kW of average power
C. Gaida, M. Gebhardt, T. Heuermann, F. Stutzki, C. Jauregui, and J. Limpert
Opt. Lett. 43, 5853 (2018)
Ground-state g factor of middle-Z boronlike ions
V. A. Agababaev, D. A. Glazov, A. V. Volotka, D. V. Zinenko, V. M. Shabaev, and G. Plunien
J. Phys.: Conf. Ser. 1138, 012003 (2018)
High-power frequency comb at 2 μm wavelength emitted by a Tm-doped fiber laser system
C. Gaida, T. Heuermann, M. Gebhardt, E. Shestaev, T. P. Butler, D. Gerz, N. Lilienfein, P. Sulzer, M. Fischer, R. Holzwarth, A. Leitenstorfer, I. Pupeza, and J. Limpert
Opt. Lett. 43, 5178 (2018)
Very-long distance propagation of high-energy laser pulse in air
J. Wang, W. Yu, M. Y. Yu, S. Rykovanov, J. Ju, S. Luan, K. Li, Y. Leng, R. Li, and Z.-M. Sheng
Phys. Plasmas 25, 113111 (2018)