Direkt zum InhaltDirekt zur SucheDirekt zur Navigation
▼ Zielgruppen ▼

Humboldt-Universität zu Berlin

Humboldt-Spektrum 3-4/2004

Schwerpunktheft Physik


Inhalt


11. Jahrgang · Heft 3-4/2004
ISSN 0946-641X · Preis 10,- EUR

 TITELBILD: 3-4/2004

Probeheft / Bezugsbedingungen / Impressum Probeheft Übersicht der bisherigen Beiträge (geordnet nach Fakultäten und Instituten) Beiträge Übersicht zu den bisher erschienenen Ausgaben Ausgaben Profil der Zeitschrift - Vorstellung Profil Homepage der Humboldt-Universität Homepage der Humboldt-Universität


STRING THEORY
Quantum Field Theory and String Theory
Johanna Erdmenger
Heft 3-4/2004, S. 6-9.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-7622
fax: +49-30-2093-7631

abstract
Fundamental theoretical physics has a long and outstanding tradition at Humboldt-Universität zu Berlin, connected to such famous physicists as Planck and Einstein. Today, the recent approaches of how to describe matter and its interactions will encounter exciting new challenges over the next few years. These will be triggered by new results from the next generation of particle colliders, as well as by new relations between elementary particle physics and cosmology. While quantum field theory is a universal approach to describing physical processes in a wide area of physics, string theory is a very promising candidate for a unified theory of all fundamental interactions.

zum Seitenanfang


ELEMENTARY PARTICLE PHYSICS
The Strong Force. Simulation of Quarks and Gluons
Michael Müller-Preussker / Ulrich Wolff
Heft 3-4/2004, S. 10-15.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-7859
fax: +49-30-2093-7631
e-mail: mmp@physik.hu-berlin.de
www: http://www-pha.physik.hu-berlin.de/

abstract
The standard model of elementary particles accurately describes our present view of the laws of nature on the smallest resolvable scale. It is briefly summarized in this article. In particular we focus on the theory of strong interactions and describe the technique of computer simulation necessary to reveal some of the predictions of this theory that physicists need to compare with experimental results. [Volltext]

zum Seitenanfang


EXPERIMENTAL PARTICLE PHYSICS
Astroparticle Physics with Very-High-Energy Photons
Thomas Lohse / Nikolaj Pavel
Heft 3-4/2004, S. 18-23.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-7820
fax: +49-30-2093-7642
e-mail: lohse@ifh.de
www: http://www-eep.physik.hu-berlin.de

abstract
When in 1912 the Austrian physicist and Nobel Prize winner Victor Francis Hess discovered the cosmic rays, an intensive radiation from the universe, consisting mainly of high energy protons and heavier atomic nuclei, he couldn't know that this was the beginning of a long and exciting story. Not only was modern elementary particle physics born in the research on cosmic rays. But also the quest for the origin of this radiation and the astrophysics of its sources developed into a fascinating field of research with plenty of unanswered questions and phenomena not fully understood. The sources of cosmic rays are probably violent energy transformers like supernovae, neutron stars and black holes. The Humboldt-Universität groups for experimental particle physics are participating in a coordinated international effort to solve this almost 100 year old puzzle. Two observatories for highest energy gamma-rays have been constructed to identify the sources of high energy radiation in the northern and the southern sky. They open a new frequency window for astronomy which allows studying the laws of nature under extreme conditions far from anything realizable in earth-bound laboratories. [Volltext]

zum Seitenanfang


EXPERIMENTAL PARTICLE PHYSICS
Probing the Formation. Process of Matter with Charm and Beauty Quarks
Martin zur Nedden
Heft 3-4/2004, S. 24-27.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-7671
fax: +49-30-2093-7642
e-mail: nedden@mail.desy.de
www: http://www.desy.de/~nedden

abstract
The experiment HERA-B at DESY Hamburg is investigating the production of charm and beauty quarks to shed light on the formation process of bound states of quarks within nuclear matter. On the one hand this is an important contribution to test different models describing how quarks form particles, we can observe in experiments. On the other hand, the results of HERA-B have a major impact on the interpretation of recent experiments producing a quark-gluon plasma, a new state of matter which exists only at extremely high temperatures and densities like those present in the Universe directly after the Big Bang. [Volltext]

zum Seitenanfang


EXPERIMENTAL PARTICLE PHYSICS
Deeply Probing Quarks and Gluons
Nikolaj Pavel
Heft 3-4/2004, S. 28-31.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-7817
fax: +49-30-2093-7642
e-mail: pavel@physik.hu-berlin.de
www: http://www-eep.physik.hu-berlin.de/

abstract
The ZEUS Experiment is one of the two large international experiments at the electron proton collider HERA at DESY, in which the structure of the proton is investigated with the highest precision so far reached. The proton turns out to have a very complicated dynamical structure due to processes driven by the strong interaction between its constituents, the quarks, which involves the gluons as mediator of this force. The precise measurement of the quark and gluon distributions is essential to deeply understand the nature of the strong interaction, which is mainly responsible for the formation of ordinary matter. [Volltext]

zum Seitenanfang


EXPERIMENTAL PARTICLE PHYSICS
The Eye of an Experimental Particle Physicist
Hermann Kolanoski
Heft 3-4/2004, S. 32-36.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-7604
fax: +49-30-2093-7642
e-mail: kolanoski@ifh.de
www: http://www-zeuthen.desy.de/~kolanosk/

abstract
Elementary particles are small, so small that for the »most elementary« of them, like the electrons or the quarks, it was up to now not possible to determine any extension. To have no extension, means to be point-like in a mathematical sense. How then, you might ask, can a physicist see such particles and even determine their identities and kinematical variables? That is what I want to explain in this article: how the particles interact with the matter they are passing through, how these interactions are exploited to detect particles and how this is done in practice by a – sometimes quite huge – particle detector. I will show with a selected example how physicists from the Humboldt-Universität have contributed to the development of state-of-the-art detectors. [Volltext]

zum Seitenanfang


EXPERIMENTAL PARTICLE PHYSICS
Electron Emission from Surfaces. How Do Fast Atomic Projectiles Extract Electrons from Solids?
Helmut Winter / Sven Lederer
Heft 3-4/2004, S. 38-42.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-7891
fax: +49-30-2093-7899
e-mail: helmut.winter@physik.hu-berlin.de
www: http://www.hu-pgd.de

abstract
The emission of electrons from solid surfaces induced by atomic particles is studied via the coincident detection of the projectile energy loss and the number of emitted electrons. This new type of »translation energy spectroscopy« applied to atom-surface scattering allows one to investigate in detail the relevant electronic processes, i.e., to relate the dissipation of projectile energy to the emission of a specific number of emitted electrons. With this method we could clear up the different microscopic interaction mechanisms for the emission of electrons from insulator and metal surfaces and explain the at first sight surprising feature of a more efficient emission of electrons tightly bound in crystals of insulators compared to clean metal surfaces. [Volltext]

zum Seitenanfang


CRYSTALLOGRAPHY
Advanced Analysis of Modern Nanostructured Materials by Means of Transmission Electron Microscopy
Wolfgang Neumann / Holm Kirmse / Reinhard Otto / Irmela Hähnert
Heft 3-4/2004, S. 44-48.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-7761
fax: +49-30-2093-7760
e-mail: wolfgang.neumann@physik.hu-berlin.de
www: http://crysta.physik.hu-berlin.de/

abstract
For advanced materials particular properties can be tailored by designing internal structures of reduced dimensions down to nanometer scale (10-9 m). Such nanostructured materials comprise all classes of materials, i.e., metals, alloys, ceramics, semiconductors, polymers, biomaterials, etc. The specific materials behaviour is essentially controlled both by the intrinsic structure and chemistry of these nanoscopic objects. Therefore, the quantitative information about microstructure and composition on a nanometer scale is indispensable getting a thorough understanding of structure-property relationships of nanostructured materials. Nowadays, transmission electron microscopy (TEM) is an analytical tool providing local information with high resolution (spatial resolution: sub-Å, energy resolution: sub-eV) about both structure and chemistry. [Volltext]

zum Seitenanfang


HOCHTEMPERATUR-SUPRALEITUNG
Die elektronische Struktur der Wismut-Hochtemperatur-Supraleiter
Recardo Manzke / Alica Krapf / Lenart Dudy / Beate Müller / Christoph Janowitz
Heft 3-4/2004, S. 50-54.
Kontakt:
Humboldt-Universität zu Berlin
Mathematisch-Naturwissenschaftliche Fakultät I
Institut für Physik
Newtonstr. 15
D-12489 Berlin-Adlershof
Tel.: +49-30-2093-7853
Fax: +49-30-2093-7795
E-Mail: recardo.manzke@physik.hu-berlin.de
www: http://htc.physik.hu-berlin.de/

abstract
Ein Ziel unserer Forschung ist das mikroskopische Verständnis des Mechanismus der Hochtemperatur-Supraleitung. Hierbei verfolgen wir zwei Strategien: Anwendung von Spektroskopien möglichst hoher Auflösung zur Untersuchung der elektronischen Struktur – im Mittelpunkt steht hier die winkelaufgelöste Photoemission – und systematische Variation der supraleitenden Materialien und ihrer Eigenschaften durch eine eigene Kristallzucht, wobei wir uns hier auf die Bi-Familie mit der Strukturformel Bi2Sr2Can-1CunO2n+4+d spezialisiert haben. Hier sind wir in der Lage, Einkristalle von n=1 (Tc,max=35K) bis n=3 (Tc,max=110K) herzustellen und die Konzentration der Löcher durch Dotierung mit dreiwertigen Elementen nahezu kontinuierlich zu verändern. Neuerdings gelingt uns auch ein ›sanfteres‹ Dotierungsverfahren durch gezielte Substituierung des Bi durch Pb. – In einem aktuellen Vorhaben führen wir Untersuchungen zur Eindimensionalität der elektronischen Struktur der CuO2-Ebenen dieser Materialien mittels polarisationsabhängiger Photoemission durch, über die hier beispielhaft berichtet wird. Die von uns erstmalig beobachtete Eindimensionalität der CuO2-Ebene könnte eine Schlüsselrolle in der Aufklärung der Hochtemperatur-Supraleitung einnehmen. [Volltext]

zum Seitenanfang


RÖNTGENBEUGUNG
Nanostrukturen und Röntgenaugen. Einblick in den Submikrometerbereich mit Röntgenstrahlen
Rolf Köhler
Heft 3-4/2004, S.56-59 .
Kontakt:
Humboldt-Universität zu Berlin
Mathematisch-Naturwissenschaftliche Fakultät I
Institut für Physik
Newtonstr. 15
D-12489 Berlin-Adlershof
Tel.: +49-30-2093-4818
Fax: +49-30-2093-7760
E-Mail: rolf.koehler@physik.hu-berlin.de
www: http://x-ray2.physik.hu-berlin.de

abstract
Dass man mittels Röntgenstrahlen in das Innere des menschlichen Körpers sehen kann, weiß wohl jeder. Zum populärwissenschaftlichen Wissen gehört wohl auch, dass man leider keine Linsen für Röntgenstrahlung habe und so auch kein Röntgenmikroskop bauen könne. Es gibt aber heute Röntgenmikroskope und noch eine ganze Reihe anderer Möglichkeiten, um Strukturen viel kleiner als ein Mikrometer (1 µm = 0,001 mm), d.h. also im Nanometerbereich (1 nm = 0,001 µm), mit Röntgenstrahlen zu untersuchen. Für die Charakterisierung von Halbleiternanostrukturen eignet sich sehr gut die Röntgenbeugung. Dabei wird kein direktes Bild der Strukturen erzeugt, sondern ein Beugungsmuster, aus dem man auf Eigenschaften der Nanostrukturen wie Form, Größe, innere Verspannung und räumliche Verteilung schließen kann. [Volltext]

zum Seitenanfang


NANOACOUSTICS
High-Frequency Acoustic Wave Fields under the Microscope
Reinhold Koch / Thorsten Hesjedal / Klaus Ploog
Heft 3-4/2004, S. 62-65.
Contact:
Paul Drude-Institute for Solid State Electronics
Hausvogteiplatz 5-7
D-10117 Berlin
phone: +49-30-20377-352
fax: +49-30-20377-201
e-mail: ploog@pdi-berlin.de
www: http://www.pdi-berlin.de/nanoac/nanoac.shtml

abstract
Nanoacoustics deals with the study of propagation, scattering, diffraction and localization phenomena of acoustic waves on the nanometer length scale, providing important information for the operation of technologically relevant high-frequency filter devices employed, e.g., in mobile phones. Even visualization of the elementary motion of the crystal lattice on an atomic scale has recently become possible. Moreover, since the elastic material properties are accessible to ultrasound, novel nanoacoustics techniques provide a means to study the elastic properties of nanoscopic materials as well as the interplay of elastic phenomena with optical and electronic properties. [Volltext]

zum Seitenanfang


STATISTISCHE PHYSIK
Statistische Physik komplexer Systeme
Udo Erdmann / Lutz Schimansky-Geier / Igor Sokolov
Heft 3-4/2004, S. 66-70.
Kontakt:
Humboldt-Universität zu Berlin
Mathematisch-Naturwissenschaftliche Fakultät I
Institut für Physik
Newtonstr. 15
D-12489 Berlin-Adlershof
Tel.: +49-30-2093-7624
Fax: +49-30-2093-7638
E-Mail: lutz.schimansky-geier@physik.hu-berlin.de
www: http://summa.physik.hu-berlin.de/~alsg

abstract
Hundert Jahre nach Einsteins Arbeit zur Brownschen Bewegung lässt sich feststellen, dass dieser Artikel den Grundstein der modernen statistischen Physik des Nichtgleichgewichts gelegt hat. Die Erklärung der Brownschen Bewegung durch Einstein basierte auf der Vorstellung der unabhängigen Bewegung der frei in der Flüssigkeit suspendierten Teilchen, die Wechselwirkung zwischen den Teilchen wurde vernachlässigt und es wurde angenommen, dass die molekularen Stöße, welche die Brownsche Bewegung verursachen, so chaotisch sind, dass die Bewegung der Teilchen sofort unvorhersagbar wird. Im Unterschied zur klassischen Brownschen Bewegung sind in komplexen Systemen die Einflüsse von Gedächtnis und Wechselwirkung nicht zu vernachlässigen. In diesem Beitrag werden drei illustrative Beispiele zum Verhalten eben solcher Systeme diskutiert und gezeigt, welche unerwarteten Effekte die Kombination aus Wechselwirkung und Zufallskraft erzeugen kann.

zum Seitenanfang


PHYSICS OF MACROMOLECULES
A Workbench for Single Macromolecules
Jürgen P. Rabe
Heft 3-4/2004, S. 72-75.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-7788
fax: +49-30-2093-7632
e-mail: rabe@physik.hu-berlin.de
www: http://pmm08.physik.hu-berlin.de/

abstract
Single macromolecules in controlled molecular environments are the fundamental information processing entities in living systems. They perform with a mind boggling efficiency: Our genome is stored in single polynucleic acids, antibodies recognize single antigens in a body, and proteins detect single photons and convert their energy highly efficient into electric energy. Since there has been enormous progress in understanding the underlying mechanisms of these processes in recent years, one may ask whether single macromolecules may not also be used for information processing in man-made, biomimetic systems. In other words, would the laws of physics allow new bio- and information technologies on the nanometer scale? In order to carry out experiments with single macromolecules we developed a workbench, which allows to move, bend and stretch, to cut and link, as well as to measure properties of single macromolecules at solid-liquid interfaces. It consists of a single crystalline substrate, suitably functionalized with a molecular top layer. Nanostructure and molecular dynamics of the molecular layer, together with the forces exerted by scanning probes, i.e. atomically sharp tips in a scanning tunneling microscope (STM) or a scanning force microscopy (SFM), are employed to control the conformation of macromolecules at surfaces, as well as for metrology. The workbench is used, e.g., to manipulate DNA or to demonstrate a single-molecule chemical field-effect transistor with nanometer-sized gates. [Volltext]

zum Seitenanfang


PHOTOBIOPHYSICS
Tetrapyrroles. Photophysical Properties and Light Induced Transfer Processes
Beate Röder
Heft 3-4/2004, S. 78-81.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-7612
fax: +49-30-2093-7666
e-mail: roeder@physikhu-berlin.de
www: http://www-pbp.physik.hu-berlin.de/

abstract
Tetrapyrroles play an important role in most biological processes of energy and electron transfer like photosynthesis or in the respiratory chain. On the other hand beside natural tetrapyrroles artificial tetrapyrroles like phtalocyanines become more and more important not only as colours but also as photoactive compounds in photovoltaic, photomedicine, molecular electronics and others. Because of their key role for light induced transfer processes in nature and their importance in constructing biomimetic systems the scientific interest of the group is focused on the investigation of electronic properties of these substances under very different conditions. [Volltext]

zum Seitenanfang


CHEMICAL PHYSICS
Ultrafast Energy Transfer in Molecular Nanostructures. Computational Studies on Photosynthetic Antenna Systems
Ben Brüggemann / Volkhard May
Heft 3-4/2004, S. 82-86.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-4821
fax: +49-30-2093-4725
e-mail: may@physik.hu-berlin.de
www: http://www-semic.physik.hu-berlin.de/AG_May/

abstract
Nanotechnology tries to build up systems with basic functional units having even the size of single molecules. To get an idea of what is possible on this length-scale, different types of theoretical studies are mandatory. Numerical simulations are of huge significance which give a view on the spatial structure of the respective nanosystem. But calculations on the electronic energy level scheme are also very helpful. And often, simulations may become necessary which highlight the dynamic behavior of nanostructures related, e.g. to the action of external fields. The present article reports on the description of ultrafast laser pulse driven dynamics in specific molecular nanostructures called light-harvesting antennae. They are found in the photosynthetic apparatus of bacteria and higher plants. Such photosynthetic antennae represent perfect objects for studying dynamics in nanosystems because of their very precise defined spatial structure and the possibility to isolate them from the cell membrane. And, it is a specialty of these antennae that a quantum dynamical description of the internal energy motion is inevitable. [Volltext]

zum Seitenanfang


PHOTONICS
New Routes to Self-Organization in Semiconductor Lasers
Fritz Henneberger / Hans-Jürgen Wünsche
Heft 3-4/2004, S. 88-92.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-7670
fax: +49-30-2093-7886
e-mail: henne@physik.hu-berlin.de
www: http://photonik.physik.hu-berlin.de/

abstract
Multi-section DFB lasers represent a new class of optical devices. The combination of nonlinearity and feedback creates novel dynamical scenarios that resemble self-organization strategies in complex chemical, biological or even sociological systems. Smallness, robustness, wide tunability as well as flexible modes of operation make multi-section lasers promising candidates for the application in existing and future optical communication networks. [Volltext]

zum Seitenanfang


NANOOPTICS
Light – Matter Interaction on the Nanoscale
Oliver Benson
Heft 3-4/2004, S. 94-96.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Hausvogteiplatz 5-7
D-10117 Berlin
phone: +49-30-2093-4711
fax: +49-30-2093-4718
e-mail: oliver.benson@physik.hu-berlin.de
www: http://nano.physik.hu-berlin.de

abstract
In 1959 the physicist Richard P. Feynman held a famous talk entitled »There's plenty of room at the bottom«. In this talk he concluded that there is no physical limit on miniaturization that prevents to make devices from single molecules or atoms. At that time the technology was far from that limit, however, todays nanotechnology allows indeed to detect and manipulate single quantum particles. [Volltext]

zum Seitenanfang


PRECISION TESTS OF RELATIVITY
Modern Optical Tests of Special Relativity
Achim Peters
Heft 3-4/2004, S. 98-100.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Hausvogteiplatz 5-7
D-10117 Berlin
phone: +49-30-2093-4905
fax: +49-30-2093-4718
e-mail: achim.peters@physik.hu-berlin.de
www: http://qom.physik.hu-berlin.de/

abstract
»The speed of light is finite and does not depend on the motion of either source or observer«. This is the fundamental statement underlying Albert Einstein's theory of Special Relativity. First formulated early in the 20th century, this theory now is one of the cornerstones of our scientific understanding of the world and tightly woven into the fabric of modern physical theories. It also has become more and more relevant for daily life – timekeeping using modern atomic clocks and navigation using the global positioning system are just two examples. Due to this outstanding role, it always has been of prime importance to experimentally verify the validity of the underlying theory. Optical tests, as presented here, are especially well suited for this task. [Volltext]

zum Seitenanfang


MODERN OPTICS
Modern Optics. Theoretical Atomic, Molecular, and Optical Physics
Alejandro Saenz
Heft 3-4/2004, S. 102-104.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Hausvogteiplatz 5-7
D-10117 Berlin
phone: +49-30-2093-4902
fax: +49-30-2093-4718
e-mail: alejandro.saenz@physik.hu-berlin.de
www: http://amo.physik.hu-berlin.de

abstract
The research group Modern Optics investigates a variety of different topics in the field of theoretical atomic, molecular, and optical physics. This ranges from the behaviour of atoms and molecules in ultra-short, ultra-intense laser pulses, over coherent control of (chemical) reactions and the physics of ultra-cold atomic and molecular gases to the interaction of matter with antimatter. The research mainly aims for the understanding of fundamental processes in mostly small molecular systems under extreme or very unusual conditions. [Volltext]

zum Seitenanfang


ULTRAFAST SPECTROSCOPY
Ultrafast Structural Dynamics in Condensed Matter
Thomas Elsässer
Heft 3-4/2004, S.106-109 .
Contact:
Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy
Max-Born-Str. 2 A
D-12489 Berlin
phone: +49-30-6392-1401
fax: +49-30-6392-1409
e-mail: elsasser@mbi-berlin.de
www: http://www.mbi-berlin.de

abstract
Basic processes in Nature such as phase transitions or (bio)chemical reactions are connected with structural changes of matter. The spatial rearrangement of electrons and nuclei, the formation and breaking of chemical bonds, as well as atomic and molecular motions underlie those events. In liquids and solids, atoms and molecules couple through a variety of short- and long-range interactions, leading to structural changes on ultrafast time scales between 10-15 s [1 femtosecond (fs)] and 10-12 s [1 picosecond (ps)]. Nonlinear optical spectroscopy with femtosecond light pulses represents the only technique for inducing and probing such events in real-time, similar to recording a sequence of »snapshots« in photography on much slower time scales. [Volltext]

zum Seitenanfang


PLASMA PHYSICS
Plasma Physics at the Humboldt-Universität zu Berlin
Gerd Fußmann
Heft 3-4/2004, S. 110-112.
Contact:
Humboldt-Universität zu Berlin
Faculty of Mathematics and Natural Sciences I
Department of Physics
Newtonstr. 15
D-12489 Berlin-Adlershof
phone: +49-30-2093-7551
fax: +49-30-2093-7531
e-mail: gerd.fussmann@physik.hu-berlin.de
www: http://plasma.physik.hu-berlin.de

abstract
Plasma-material interaction studies and investigation of highly charged ions is the major field of activity in the plasma physics group at the Humboldt-Universität zu Berlin. Two experimental facilities are being operated: The linear plasma generator PSI-2 and an electron beam ion trap (EBIT) device. EBIT produces and stores highly charged ions of up to the heaviest elements in the periodic table. The scientific emphasis of the EBIT is on atomic physics research and applications to fusion-relevant hot plasmas. The PSI-2 generator is a stationary source producing plasmas with parameters very close to the conditions in the boundary region of nuclear fusion devices. The project focuses on basic plasma physics, development and experimental testing of diagnostic components, plasma-material interaction, and material characterization. This article gives an overview of the two facilities and the research projects including results from recent X-ray spectroscopic measurements and chemical erosion. [Volltext]

zum Seitenanfang


DIDAKTIK DER PHYSIK
Lernen mit neuen Medien. Multimedia und Internet im Physikunterricht
Burkhard Priemer / Lutz-Helmut Schön
Heft 3-4/2004, S. 114-117.
Kontakt:
Humboldt-Universität zu Berlin
Mathematisch-Naturwissenschaftliche Fakultät I
Institut für Physik
Newtonstr. 15
D-12489 Berlin-Adlershof
Tel.: +49-30-2093-7945
Fax: +49-30-2093-7795
E-Mail: schoen@physik.hu-berlin.de
www: http://didaktik.physik.hu-berlin.de

abstract
Das Internet gehört zum selbstverständlich genutzten Medium im Alltag von Schülern und Studenten. Zunehmende Bedeutung erlangt das World Wide Web (WWW) dabei nicht nur für die Freizeit. Auch die Recherche nach ausbildungsrelevanten Themen findet vermehrt online statt. Dieser intensiven Internetnutzung zu Lernzwecken steht ein schwer zu überblickendes, buntes und vielfältiges Webseitenangebot gegenüber, das nur in den seltensten Fällen einer didaktischen Aufbereitung oder überhaupt einer inhaltlichen Qualitätskontrolle unterliegt. Hieraus ergeben sich eine Reihe fach- sowie mediendidaktischer Fragestellungen: Wie wenden Schüler das Internet an, wenn sie für die Schule ein Thema erarbeiten? Wie navigieren sie? Welche Lernerfolge erzielen sie dabei? Antworten auf diese Fragen können helfen, die Gestaltung von neuen Medien sowie deren Nutzung im Unterricht an die Bedürfnisse der Lerner anzupassen. [Volltext]

zum Seitenanfang


DIDAKTIK DER PHYSIK
Das UniLab Adlershof. Mehr als ein Schülerlabor
Renate Brechel / Andreas Palmer / Lutz-Helmut Schön
Heft 3-4/2004, S. 118-119.
Kontakt:
Humboldt-Universität zu Berlin
Mathematisch-Naturwissenschaftliche Fakultät I
Institut für Physik
UniLab Schülerlabor
Brook-Taylor-Straße 1
D-12489 Berlin-Adlershof
Tel.: +49-30-2093-7996
Fax: +49-30-2093-7981
E-Mail: info@unilab-adlershof.de
www: http://www.unilab-adlershof.de

abstract
Seit Januar 2004 arbeitet im Gebäude des Großen Windkanals auf dem Universitätscampus Adlershof das UniLab – eine Initiative der Arbeitsgruppe Didaktik der Physik im Institut für Physik der Humboldt-Universität zu Berlin. UniLab will als außerschulischer Lernort eine tragfähige Brücke schlagen zwischen Schule und Forschung. Gleichzeitig will es – und das ist das Besondere – die Ausbildung von Studierenden um praxis- und forschungsnahe Elemente bereichern. Wissenschaftler der benachbarten Forschungsinstitute erhalten durch UniLab Impulse für die Vermittlung komplexen Wissens. In den kommenden Jahren soll UniLab durch eine wissenschaftliche Galerie und ein Institut für didaktische Forschung erweitert werden. [Volltext]

zum Seitenanfang


Veröffentlichungen / Wissenschaftspreis
[Volltext]