On production and asymmetric focusing of flat electron beams using rectangular capillary discharge plasmas

A method for the asymmetric focusing of electron bunches, based on the active plasma lensing technique, is proposed. This method takes advantage of the strong inhomogeneous magnetic field generated inside the capillary discharge plasma to focus on the ultrarelativistic electrons. The plasma and magnetic field parameters inside the capillary discharge are described theoretically and modeled with dissipative magnetohydrodynamic computer simulations enabling analysis of the capillaries of rectangle cross-sections. Large aspect ratio rectangular capillaries might be used to transport electron beams with high emittance asymmetries, as well as assist in forming spatially flat electron bunches for final focusing before the interaction point

Leader Ethical Decision-Making in Organizations: Strategies for Sensemaking

Organizational leaders face environmental challenges and pressures that put them under ethical risk. Navigating this ethical risk is demanding given the dynamics of contemporary organizations. Traditional models of ethical decision-making (EDM) are an inadequate framework for understanding how leaders respond to ethical dilemmas under conditions of uncertainty and equivocality. Sensemaking models more accurately illustrate leader EDM and account for individual, social, and environmental constraints. Using the sensemaking approach as a foundation, previous EDM models are revised and extended to comprise a conceptual model of leader EDM. Moreover, the underlying factors in the model are highlighted—constraints and strategies. Four trainable, compensatory strategies (emotion regulation, self-reflection, forecasting, and information integration) are proposed and described that aid leaders in navigating ethical dilemmas in organizations. Empirical examinations demonstrate that tactical application of the strategies may aid leaders in making sense of complex and ambiguous ethical dilemmas and promote ethical behavior. Compensatory tactics such as these should be central to organizational ethics initiatives at the leader level

Measurement of b quark fragmentation fractions in the production of strange and light B mesons in p(p)over-bar collisions at root s=1.8 TeV

A new technique to measure the ratio of b quark fragmentation fractions in collisions is described. Using a 70-pb(-1) sample of low-mass dimuon trigger data recorded with the Collider Detector at Fermilab, we identify B mesons by observing the double semileptonic decays b-->c mu X with c-->s mu X. By counting the numbers of K*(892)(0), K*(892)(+), and phi(1020) mesons produced in association with these muon pairs, we measure the ratio of strange to nonstrange B meson production to be f(s)/(f(u)+f(d)) = [21.0+/-3.6(stat)(-3.0)(+3.8)(syst)]%. This measurement is the most precise available from hadron collisions to date. Limits on the branching fractions of semileptonic charm meson decays with K-1(1270), K-1*(1410), and K-2*(1430) mesons in the final state are also obtained. [S0556-2821(99)00119-8]

Measurement of b quark fragmentation fractions in the production of strange and light B mesons in p(p)over-bar collisions at root s=1.8 TeV

A new technique to measure the ratio of b quark fragmentation fractions in collisions is described. Using a 70-pb(-1) sample of low-mass dimuon trigger data recorded with the Collider Detector at Fermilab, we identify B mesons by observing the double semileptonic decays b-->c mu X with c-->s mu X. By counting the numbers of K*(892)(0), K*(892)(+), and phi(1020) mesons produced in association with these muon pairs, we measure the ratio of strange to nonstrange B meson production to be f(s)/(f(u)+f(d)) = [21.0+/-3.6(stat)(-3.0)(+3.8)(syst)]%. This measurement is the most precise available from hadron collisions to date. Limits on the branching fractions of semileptonic charm meson decays with K-1(1270), K-1*(1410), and K-2*(1430) mesons in the final state are also obtained. [S0556-2821(99)00119-8]

Assessing written work by determining competence to achieve the module-specific learning outcomes.

This chapter describes lasers and other sources of coherent light that operate in a wide wavelength range. First, the general principles for the generation of coherent continuous-wave and pulsed radiation are treated including the interaction of radiation with matter, the properties of optical resonators and their modes as well as such processes as Q-switching and mode-locking. The general introduction is followed by sections on numerous types of lasers, the emphasis being on todayʼs most important sources of coherent light, in particular on solid-state lasers and several types of gas lasers. An important part of the chapter is devoted to the generation of coherent radiation by nonlinear processes with optical parametric oscillators, difference- and sum-frequency generation, and high-order harmonics. Radiation in the extended ultraviolet (EUV) and x-ray ranges can be generated by free electron lasers (FEL) and advanced x-ray sources. Ultrahigh light intensities up to 1021 W/cm2 open the door to studies of relativistic laser–matter interaction and laser particle acceleration. The chapter closes with a section on laser stabilization