We have designed, constructed, and tested a system that pre-selects the biological fraction of airborne particles from the overall aerosol. The preselection is based on fluorescence emission excited by a continuous 266 nm laser beam. This beam is one of two cw beams used to measure the aerodynamic particle size of sampled particles. The intention in our system is that single particles, based on...

An algorithm for optimizing beam orientations and beam weights for conformal radiotherapy has been developed. The algorithm models the optimization of beam orientations and beam weights as a problem of mixed integer linear programming (MILP), and optimizes the beam orientations and beam weights simultaneously. The application process of the algorithm has four steps: (a) prepare a pool of beam o...

The ELSA stretcher ring of Bonn University serves external hadron physics experiments with a quasi continuous electron beam of up to 3.2 GeV energy. Ions, being generated by collisions of the circulating electrons with the residual gas molecules, accumulate inside the beam potential, causing incoherent tune shifts and coherent beam instabilities. Detailed measurements were carried out in which ...

The potential gain of luminosity by both focusing and colliding e+ebeams in an underdense plasma is investigated. We first suggest the possibility of creating the plasma by the beam self-induced “tunneling ionization” of a gas. We then study the beam optics in the continuous focusing environment provided by the plasma, and the subsequent e + e beam-beam interaction in the same plasma. When appl...

We report on the first experimental demonstration of purification of nonclassical continuous variable states. The protocol uses two copies of phase-diffused states overlapped on a beam splitter and provides Gaussified, less mixed states with the degree of squeezing improved. The protocol uses only linear optical devices such as beam splitters and homodyne detection, thereby proving these optica...

The nonlinear interaction of a tenuous continuous electron beam with a traveling electromagnetic wave in the cyclotron resonance laser accelerator is analyzed using a single-particle model and multi-particle simulation. It is found that the maximum beam energy gain and acceleration distance obey certain scaling laws for optimized systems, and that the maximum energy gain is limited primarily by...

The paper presents a continuous speech recognition system which integrates an additional acoustic knowledge source into the data-driven beam search algorithm. Details of the object oriented implementation of the beam search algorithm will be given. Integration of additional knowledge sources is treated within the flexible framework of Dempster-Shafer theory. As a first example, a rule-based plo...

Siegman [Opt. Lett. 18, 675 (1993)] showed that binary-phase plates cannot improve laser beam quality. We demonstrate that continuous spiral phase elements can improve the quality of beams that originate from a laser operating with a pure high-order transverse mode. A theoretical analysis is presented, along with experimental results obtained with a CO(2) laser. The results reveal that a nearly...

We analyze the phase shift induced in an amplitude-modulated laser beam propagating through a water dispersion of graphene oxide sheets in a fiber-to-fiber U-bench. This phase shift arises from the thermally induced nonlinear refraction in the sample. The system exhibits strong optical limiting performance for weak continuous-wave signals. A theoretical model including beam propagation and ther...