Superconducting bending magnets for compact synchrotron radiation source
A 180 degrees superconducting magnet has been constructed for a synchrotron radiation source. The authors describe the superconducting magnet design and some component test results for the compact synchrotron radiation source. The magnetic field at the electron orbit is 4.5 T. The bending radius is 0.593 m. The magnet has several features such as low liquid helium consumption ratio, persistent current operation, high homogeneous magnetic fields, and leakage flux shielding by the iron core surrounding the cryostat. Component tests of persistent current switches of 15 Omega and 3 Omega and a superconducting joint test have been performed.<<ETX>>
Field Correction of a Quadrupole Magnet and a Skew-Quadrupole Magnet By Using Iron Plates Attached to the End Shaping
It is well known that magnetic field linearities of the conventional quadrupole magnet and the skew-quadrupole magnet are improved by the end shaping of the pole. We found that small iron plates which were attached to the end shaping changed field distributions and radial and azimuthal multipole error components were cancelled by selecting the optimum mass of iron plates. The optimum mass was determined from a few field measurements easily. In addition, we found that the transverse distribution of the field gradient of the quadrupole magnet changed concavely according to increasing iron plates and the that distribution of the skew-quadrupole magnet changed convexly in reverse. This difference of the change of the field is due to the difference of the sign of the dodecapole error component between the quadrupole magnet and the skew-quadrupole magnet
Struggles for Visibility
This article addresses the ways in which terrorists are rendered visible in the news media. By studying images used in coverage of terrorists, the article focuses on the visual construction of this figure, which symbolizes the public’s notion of the “enemy”, in terms of specific attacks and the general threat thereof as well as terrorist actors, networks, and ideologies. The article takes its point of departure in the assumption that two visual forms are prevalent for representing terrorists in the news media, “surveillance representations” and “self-representations”. Based on this assumption, the article is guided by a principal research question, namely: How are terrorists made visible in the news media through surveillance representations and self-representations and what are the prevalent genres for visually representing terrorist actors? The article draws on a theoretical framework concerning the news media’s propensity to personalize the terrorist and the mediated visibility of terrorists. Empirically, the article is based on a quantitative content analysis of coverage of terrorism by Danish public service broadcasters DR and TV2 in 2016 to provide an overview of the proportions between surveillance representations and self-representations and develop a typology of the most widespread genres: ID photography, surveillance footage, selfies and similar, and private snapshots.