Model solution for volume reflection of relativistic particles in a bent crystal

For volume reflection process in a bent crystal, exact analytic expressions for positively- and negatively-charged particle trajectories are obtained within a model of parabolic continuous potential in each interplanar interval, with the neglect of incoherent multiple scattering. In the limit of the crystal bending radius greatly exceeding the critical value, asymptotic formulas are obtained for the particle mean deflection angle in units of Lindhard's critical angle, and for the final beam profile. Volume reflection of negatively charged particles is shown to contain effects of rainbow scattering and orbiting, whereas with positively charged particles none of these effects arise within the given model. The model predictions are compared with experimental results and numerical simulations. Estimates of the volume reflection mean angle and the final beam profile robustness under multiple scattering are performed.Comment: 21 pages, 11 figure

The limits of volume reflection in bent crystals

We show that theory predictions for volume reflection in bent crystals agree with recent experimental data. This makes possible to predict volume reflection angle and efficiency in a broad range of energy for various crystals. A simple formula is proposed for volume reflection efficiency. We derive the physical limits for application of crystal reflection at high-energy accelerators where it may help beam collimation.Comment: 6 pages, 2 figure

Introduction: Examined Live – An Epistemological Exchange Between Philosophy and Cultural Psychology on Reflection

Besides the general agreement about the human capability of reflection, there is a large area of disagreement and debate about the nature and value of “reflective scrutiny” and the role of “second-order states” in everyday life. This problem has been discussed in a vast and heterogeneous literature about topics such as epistemic injustice, epistemic norms, agency, understanding, meta-cognition etc. However, there is not yet any extensive and interdisciplinary work, specifically focused on the topic of the epistemic value of reflection. This volume is one of the first attempts aimed at providing an innovative contribution, an exchange between philosophy, epistemology and psychology about the place and value of reflection in everyday life. Our goal in the next sections is not to offer an exhaustive overview of recent work on epistemic reflection, nor to mimic all of the contributions made by the chapters in this volume. We will try to highlight some topics that have motivated a new resumption of this field and, with that, drawing on chapters from this volume where relevant. Two elements defined the scope and content of this volume, on the one hand, the crucial contribution of Ernest Sosa, whose works provide original and thought-provoking contributions to contemporary epistemology in setting a new direction for old dilemmas about the nature and value of knowledge, giving a central place to reflection. On the other hand, the recent developments of cultural psychology, in the version of the “Aalborg approach”, reconsider the object and scope of psychological sciences, stressing that “[h]uman conduct is purposeful”

Dependence of microwave absorption properties on ferrite volume fraction in MnZn ferrite/rubber radar absorbing materials

We report the analysis of measurements of the complex magnetic permeability ($\mu_r$) and dielectric permittivity ($\epsilon_r$) spectra of a rubber radar absorbing material (RAM) with various MnZn ferrite volume fractions. The transmission/reflection measurements were carried out in a vector network analyzer. Optimum conditions for the maximum microwave absorption were determined by substituting the complex permeability and permittivity in the impedance matching equation. Both the MnZn ferrite content and the RAM thickness effects on the microwave absorption properties, in the frequency range of 2 to 18 GHz, were evaluated. The results show that the complex permeability and permittivity spectra of the RAM increase directly with the ferrite volume fraction. Reflection loss calculations by the impedance matching degree (reflection coefficient) show the dependence of this parameter on both thickness and composition of RAM.Comment: 9 pages, 6 figures; accepted for the Journal of Magnetism and Magnetic Material

On an extremal problem connected with simplices

In this note we investigate the behavior of the volume that the convex hull of two congruent and intersecting simplices in Euclidean $n$-space can have. We prove some useful equalities and inequalities on this volume. For the regular simplex we determine the maximal possible volume for the case when the two simplices are related to each other via reflection at a hyperplane intersecting them.Comment: 11 page

Volume 2, Number 1: From the Editor: Renewal, Refreshment and Reflection

Welcome to the Summer 2006 issue of the ICCTE Journal. In May of 2006, a little over one month ago, about 90 teacher educators and others gathered at Regent University in Virginia Beach, Virginia for the CCTE conference. It was a wonderful time of renewal and refreshment, as well as a time to be challenged and encouraged in our work as educators. I would like to extend my thanks and appreciation to our colleagues at Regent University who worked diligently to plan for and deliver a wonderful conference. The 2008 conference will be hosted by Gordon College, in the Boston area

Comments on theory of volume reflection and radiation in bent crystals

Recent theoretical results on charged particle interaction with planarly oriented thin bent crystals are reviewed, with the emphasis on dynamics in the continuous potential. Influence of boundary conditions on the volume-reflected beam profile is discussed. Basic properties of coherent bremsstrahlung in a bent crystal are highlighted.Comment: 10 pages, 4 figure