Coherent control with shaped femtosecond laser pulses applied to ultracold molecules

We report on coherent control of excitation processes of translationally ultracold rubidium dimers in a magneto-optical trap by using shaped femtosecond laser pulses. Evolution strategies are applied in a feedback loop in order to optimize the photoexcitation of the Rb2 molecules, which subsequently undergo ionization or fragmentation. A superior performance of the resulting pulses compared to unshaped pulses of the same pulse energy is obtained by distributing the energy among specific spectral components. The demonstration of coherent control to ultracold ensembles opens a path to actively influence fundamental photo-induced processes in molecular quantum gases

Influence of gun turning on shooting accuracy

W artykule przedstawiono rozważania dotyczące wpływu skręcenia broni strzeleckiej podczas celowania na, celność strzelania. Z zasad balistyki zewnętrznej wprowadzono zależności pozwalające obliczyć zboczenie pocisku i obniżenie punktu trafienia oraz zaprezentowano wyniki obliczeń dla określonych nastaw celownika przy różnych położeniach celu, wykonane dla różnych kątów skręcenia broni.Turning the gun is the aiming error of frequent occurrence among novice shooters. This error arises when the sighting blade of the rear sight is not horizontal at the moment of a bullet exit. Turning the gun has the great influence on the point of bullet impact. The longer is a distance between the barrel axis and the top of a front sight, the bigger influence for a given gun model, the influence depends on the sight setting and on the shooting range. The Siacci method for flat-fire trajectories calculation was used in the paper. It was assumed that the line of sight. It causes diminishing the elevation angle and moving the muzzle up. The formulas are derived to obtain the bullet lowering ∆γ and the bullet deflection z as a function of the gun turning angle α. It is necessary to know the ballistic coefficient c, the distance m between the barrel axis and the top of front sight, the distance a between the top of the sight plane and the muzzle plane, the distance χtar on which the gun is zeroed, the range χ (may be shorter or longer than the distance) and the turning angle α. Practical computation example for the AKM (Kalashnikov) rifle was presented to illustrate application of the method described. The paper will be of interest for military and sporting shooters which tends to improve their skills