Compensation of the Crossing Angle with Crab Cavities at KEKB

Crab cavities have been installed in the KEKB B--Factory rings to compensate the crossing angle at the collision point and thus increase luminosity. The beam operation with crab crossing has been done since February 2007. This is the first experience with such cavities in colliders or storage rings. The crab cavities have been working without serious issues. While higher specific luminosity than the geometrical gain has been achieved, further study is necessary and under way to reach the prediction of simulation.Comment: Submitted to Particle Accelerator Conference 2007, MOZAKI01, Albuquerqu

L4-LINUX BASED SYSTEM AS A PLATFORM FOR EPICS IOC-CORE

Abstract The EPICS Input/Output Controller (IOC) coreprogram, iocCore [1], is now portable to multiplatforms. The Linux operating system, among them, seems to be a promising candidate for a platform to run iocCore, considering the recent high appreciation in desktop and server use as well as control fields. The Linux kernel, however, is not suitable for timecritical applications, since it responds to external events with unpredictable latency. We summarize three known causes of the latency, and then discuss some of the different solutions and how they affect the functionality of iocCore. As a possible alternative, we propose an approach that dispatches user-level processes by a real-time kernel aiming at a consistency of availability with predictable responsiveness

INTRODUCTION OF MODERN SUBSYSTEMS AT THE KEK INJECTOR-LINAC

Abstract As an accelerator control system survives over several years, it is often the case that new subsystems are introduced into the original control system. The control system for the KEK electron/positron injector-linac has been using Unix workstations and VME computers since 1993. During the eight-year operation, we extended the system by introducing a) Windows PCs, b) PLC controllers with a network interface, and c) web servers based on modern information technology. Although such new subsystems are essential to improve control functionalities, they often cause communication problems with the original control system. We discuss the experienced problems, and present our solutions for them

RHQT Nb3Al 15-Tesla magnet design study

Feasibility study of 15-Tesla dipole magnets wound with a new copper stabilized RHQT Nb{sub 3}Al Rutherford cable is presented. A new practical long copper stabilized RHQT Nb{sub 3}Al strand is presented, which is being developed and manufactured at the National Institute of Material Science (NIMS) in Japan. It has achieved a non-copper J{sub c} of 1000A/mm{sup 2} at 15 Tesla at 4.2K, with a copper over non-copper ratio of 1.04, and a filament size less than 50 microns. For this design study a short Rutherford cable with 28 Nb{sub 3}Al strands of 1 mm diameter will be fabricated late this year. The cosine theta magnet cross section is designed using ROXIE, and the stress and strain in the coil is estimated and studied with the characteristics of the Nb{sub 3}Al strand. The advantages and disadvantages of the Nb{sub 3}Al cable are compared with the prevailing Nb{sub 3}Sn cable from the point of view of stress-strain, J{sub c}, and possible degradation of stabilizer due to cabling. The Nb{sub 3}Al coil of the magnet, which will be made by wind and react method, has to be heat treated at 800 degree C for 10 hours. As preparation for the 15 Tesla magnet, a series of tests on strand and Rutherford cables are considered

Cathepsin E Deficiency Impairs Autophagic Proteolysis in Macrophages

Cathepsin E is an endosomal aspartic proteinase that is predominantly expressed in immune-related cells. Recently, we showed that macrophages derived from cathepsin E-deficient (CatE-/-) mice display accumulation of lysosomal membrane proteins and abnormal membrane trafficking. In this study, we demonstrated that CatE-/- macrophages exhibit abnormalities in autophagy, a bulk degradation system for aggregated proteins and damaged organelles. CatE-/- macrophages showed increased accumulation of autophagy marker proteins such as LC3 and p62, and polyubiquitinated proteins. Cathepsin E deficiency also altered autophagy-related signaling pathways such as those mediated by the mammalian target of rapamycin (mTOR), Akt, and extracellular signal-related kinase (ERK). Furthermore, immunofluorescence microscopy analyses showed that LC3-positive vesicles were merged with acidic compartments in wild-type macrophages, but not in CatE-/- macrophages, indicating inhibition of fusion of autophagosome with lysosomes in CatE-/- cells. Delayed degradation of LC3 protein was also observed under starvation-induced conditions. Since the autophagy system is involved in the degradation of damaged mitochondria, we examined the accumulation of damaged mitochondria in CatE-/- macrophages. Several mitochondrial abnormalities such as decreased intracellular ATP levels, depolarized mitochondrial membrane potential, and decreased mitochondrial oxygen consumption were observed. Such mitochondrial dysfunction likely led to the accompanying oxidative stress. In fact, CatE-/- macrophages showed increased reactive oxygen species (ROS) production and up-regulation of oxidized peroxiredoxin-6, but decreased antioxidant glutathione. These results indicate that cathepsin E deficiency causes autophagy impairment concomitantly with increased aberrant mitochondria as well as increased oxidative stress