47 research outputs found
Stochastic Cooling at the ESR
Stochastic precooling at the ESR storage ring of GSI will be used mainly for experiments with stored radioactive fragment beams. They arrive from the fragment separator with momentum spreads and emittances for which electron cooling is too slow. The installation of components at the ESR is now complete and first commissioning experiments have been performed. Both longitudinal and transverse stochastic cooling have been demonstrated. The paper gives a short account of the system architecture, and of the response of quarter-wave plates and superelectrodes at intermediate energies. The preparation of fragment beams suitable for subsequent electron cooling is discussed for the case that a mixture of different ion species is present in the cooler ring. Results of commissioning and future prospects are presented
Experimental signatures of the mixed axial-gravitational anomaly in the Weyl semimetal NbP
Weyl semimetals are materials where electrons behave effectively as a kind of
massless relativistic particles known asWeyl fermions. These particles occur in
two flavours, or chiralities, and are subject to quantum anomalies, the
breaking of a conservation law by quantum fluctuations. For instance, the
number of Weyl fermions of each chirality is not independently conserved in
parallel electric and magnetic field, a phenomenon known as the chiral anomaly.
In addition, an underlying curved spacetime provides a distinct contribution to
a chiral imbalance, an effect known as the mixed axial-gravitational anomaly,
which remains experimentally elusive. However, the presence of a mixed
gauge-gravitational anomaly has recently been tied to thermoelectrical
transport in a magnetic field, even in flat spacetime, opening the door to
experimentally probe such type of anomalies in Weyl semimetals. Using a
temperature gradient, we experimentally observe a positive longitudinal
magnetothermoelectric conductance (PMTC) in the Weyl semimetal NbP for
collinear temperature gradients and magnetic fields (DT || B) that vanishes in
the ultra quantum limit. This observation is consistent with the presence of a
mixed axial-gravitational anomaly. Our work provides clear experimental
evidence for the existence of a mixed axial-gravitational anomaly of Weyl
fermions, an outstanding theoretical concept that has so far eluded
experimental detection
The Nineteenth-Century World of Turkic Dictionaries: An Overview
The author creates a bibliographic picture of the various Turkic-language dictionaries from the eleventh to the end of the nineteenth centuries, in various languages, and describes their structure. He then focuses specifically on printed Turkic dictionaries of the nineteenth century, discussing their historical context and a statistical survey that he conducted. A number of these dictionaries have been digitized; he examines some sites where they are accessible. In the appendix is a list of the dictionaries that he found in the course of his research
Die anfänge der Turkologie in den USA : aufgrund meiner eigenen erfahrungen dargestellt
Donated by Klaus Kreise
Zu einigen šamanistischen ausdrücken im altajischen und nachbargebieten
Donated by Klaus Kreise
Turkisches sprachgut im Sud-Slavischen : methodisches in seiner behandlung
Donated by Klaus Kreise