4 research outputs found
Molekulu lenkiska momenta optiska polarizacija
Available from Latvian Academic Library / LAL - Latvian Academic LibrarySIGLELVLatvi
Dynamical simulation and optimization of double-helical AUV
The paper presents an original design of autonomous underwater vehicles where
thrust forc is created by the helicoidal shape of hull rather than screw propellers. The contra-
rotating bow and stern parts create propulsion force. The middle part of the vehicle, which is
built from elastic material, contains a Cardan joint which controls bending drives (actuators). The
controlled bending of the hull allows the maneuvering of the vehicle. A bending drive velocity
control algorithm for the automatic control of the vehicle movement direction is
proposed. The dynamics of AUV are simulated using multibody simulation software MSC
Adams. For the simulation of water resistance forces and torques the surrogate
polynomial metamodels are created on the basis of computer experiments with CFD
software. The simulation results are compared with measurements of the AUV prototype, created at
Institute of Mechanics of Riga Technical University. Experiments with the prototype
showed good agreement with simulation results and confirmed the effectiveness and the future
potential of
the proposed principle
Experiments with mid-heavy antiprotonic atoms in AEgIS
ments which provide the most precise data on the strong interaction between protons and antiprotons and of the neutron skin of many nuclei thanks to the clean annihilation signal. In most of these experiments, the capture process of low energy antiprotons was done in a dense target leading to a significant suppression of specific transitions between deeply bound levels that are of particular interest. In particular, precise measurements of specific transitions in antiprotonic atoms with Z>2 are sparse.
We propose to use the pulsed production scheme developed for antihydrogen and protonium for the formation of cold antiprotonic atoms. This technique has been recently achieved experimentally for the production of antihydrogen at AEIS. The proposed experiments will have sub-ns synchronization thanks to an improved control and acquisition system. The formation in vacuum guarantees the absence of Stark mixing or annihilation from high n states and together with the sub-ns synchronization would resolve the previous experimental limitations. It will be possible to access the whole chain of the evolution of the system from its formation until annihilation with significantly improved signal-to-background ratio
Toward a pulsed antihydrogen beam for WEP tests in AEgIS
The AEg̅IS collaboration at CERN’s AD produces antihydrogen atoms in the form of a pulsed, isotropic source with a precisely defined formation time. AEg̅IS has recently undergone major upgrades to fully benefit from the increased number of colder antiprotons provided by the new ELENA decelerator and to move toward forming a horizontal beam to directly investigate the influence of gravity on the H̅ atoms, thereby probing the Weak Equivalence Principle for antimatter. This contribution gives an overview of these upgrades as well as subsequent results from the first beam times with ELENA