The ESSnuSB design study: overview and future prospects

ESSnuSB is a design study for an experiment to measure the CP violation in the leptonic sector at the second neutrino oscillation maximum using a neutrino beam driven by the uniquely powerful ESS linear accelerator. The reduced impact of systematic errors on sensitivity at the second maximum allows for a very precise measurement of the CP violating parameter. This review describes the fundamental advantages of measurement at the 2nd maximum, the necessary upgrades to the ESS linac in order to produce a neutrino beam, the near and far detector complexes, the expected physics reach of the proposed ESSnuSB experiment, concluding with the near future developments aimed at the project realization.Comment: 19 pages, 11 figures; Corrected minor error in alphabetical ordering of the authors: the author list is now fully alphabetical w.r.t. author surnames as was intended. Corrected an incorrect affiliation for two authors per their reques

Stability analysis of extension-twist coupled composite rotor blades

In a tiltrotor aircraft the difference in the inflow and the rotor speeds between hover and forward fligth modes necessitates different blade twist and chord distributions. A passive blade twist control design, referred to as The Sliding Mass Concept, has been previously proposed by the authors for performance improvement of a tiltrotor aircraft. An optimization technique was utilized which resulted in 4.4% improvement in hover performance. In this paper a stability analysis has been performed for the optimum configuration. The analysis is based on Prony series fitting on the signal data obtained from the analysis of a multibody dynamics model excited in the first three wing modes by using appropriate initial conditions. The first three symmetric wing mode damping variations with respect to the cruise speed are presented. The results are compared with an XV15 baseline design. The analysis has shown that no significant changes occur in the damping characteristics of the proposed model and that the system is aerodynamically stable. Copyright © 2005 by the American Helicopter Society International, Inc. All rights reserved

Taper Transmission Line Measurement— A Thru-Only De-embedding Approach

This article proposes a novel validated de-embedding approach to S-parameter measurement. This de-embedding approach benefits from the fully symmetric nature of the designed tapered transmission line test fixture and requires only a Through (THRU) standard. A key point of this approach is solving for a new coefficient Rx, which is defined to take into account the inherent physical properties of the transmission network. Compared to previous thru-only de-embedding methods, the present approach is applicable to a significantly wider range of frequencies and offers more flexibility in the design of the test fixture. In addition, this approach simplifies multi-port configurations compared to traditional complicated calibration methods such as TRL. For validation purposes, symmetric two and four port tapered THRUs were designed and measured. This novel de-embedding approach is verified by comparison measurements with the classic TRL method or the HFSS simulation and shows a very good agreement