Space charge compensation technology using higher-order multipole magnetic field components has been proposed to transport high-intensity charged particle beams. In order to realize this compensation ...technology in a limited beam line space, we devised a compact-size combined-function multipole permanent magnet. This magnet can produce two multipole components at the same location on the beam line. As a first step, we have designed a magnet to simultaneously generate a fixed-strength quadrupole and an adjustable-strength octupole component using permanent magnet materials. In this magnet model, the magnetic circuit consists of two groups of magnets. The first one is a group of trapezoidal magnets that occupy most of the space to generate a quadrupole magnetic field component with a magnitude of 30 T/m. The second one is an inner group of cylindrical magnets to generate an octupole component with a magnitude up to 17,000 T/m 3 . The intensity of the octupole component can be varied from 17,000 T/m 3 to 0 T/m 3 by rotating these cylindrical magnets. This design was used to build a prototype model. In this model, the modulation mechanism was implemented to verify the feasibility of the modulation scheme for the octupole magnetic field strength.
Abstract
Beam commissioning is underway at KEK’s Superconducting RF Test Facility (STF). Since beam diagnostics are important to realize stable operation, we have developed a time-resolved beam loss ...distribution monitor as one of the beam diagnostics. This monitor uses up to 16 PIN photodiodes as X-ray sensors to observe X-rays generated due to beam loss of a pulsed beam with a width of approximately 800 μs, which is divided into 100 μs intervals. Thus, 128 data can be acquired per bunch. The data is read out by an EPICS-based data acquisition system. On the other hand, we are also developing an EPICS-based data acquisition system for an inspection method for the superconducting cavities(sX-map) for the vertical test of bare cavities. sX-map strips are inserted inside the stiffener ring at the iris of superconducting cavities. In this presentation, an overview of these EPICS-based data acquisition systems and their integration with the existing control system will be presented.
Magnetic Field Shielding With Superconductors Iwashita, Y.; Kuriyama, Y.; Tongu, H. ...
IEEE transactions on applied superconductivity,
09/2022, Letnik:
32, Številka:
6
Journal Article
Recenzirano
Magnetic fields occupy an important position in many physics studies, and control of minute magnetic fields is important for measurement items in many physics experiments. This article discusses ...shielding from faint environmental magnetic field for superconducting accelerating cavities made of niobium. Niobium is a type-II superconductor, which traps the environmental magnetic flux in the material during the superconducting transition, resulting in increase of residual resistance and heating during operation. Shielding from a weak magnetic field is essential for high performance operations. A magnetic shielding method that uses the diamagnetism of superconducting materials instead of magnetic flux absorption by high magnetic permeability materials is presented.
Defatted and heat-treated soybean meal (SBM) was fermented using compound bacteria predominantly
Bacillus spp. under two different fermentation conditions until the material temperature reached 80
...°C: initial water addition of 30% (fermented for 7
h, FSBM-1) and 45% (10
h, FSBM-2). A fish meal-based diet and three non-fish meal diets containing SBM, FSBM-1 or FSBM-2 each at a 47.6% level with a 21.0% level of corn gluten meal were fed to rainbow trout (initial BW, 14.7
g) for 10
weeks. The growth and feed efficiency ratio of fish fed SBM diet and FSBM-1 diet were inferior to those of fish fed FM diet and FSBM-2 diet. Lower digestibility values of carbohydrates and lipids, especially of polar lipids observed in fish fed SBM diet were improved by the fermentation (SBM
<
FSBM-1
=
FSBM-2). Biliary bile acid content, proportion of cholyltaurine in the biliary bile, and bile acid concentration in the intestinal digesta increased by the fermentation (SBM
<
FSBM-1
<
FSBM-2). Morphological abnormalities in the distal intestine observed in fish fed SBM diet were moderately improved in fish fed FSBM-1 diet and were not observed in fish fed FSBM-2 diet. Morphological abnormalities in the liver of fish fed SBM diet were also improved in both FSBM diet groups. These results indicate that fermentation of soybean meal under appropriate conditions is beneficial for preventing various physiological abnormalities that occur in rainbow trout fed soybean meal. We conclude that properly fermented soybean meal is a promising ingredient as the main protein source in a non-fish meal diet for rainbow trout.
We employed our recently developed immuno‐electron microscopic method (W. Möbius, Y. Ohno‐Iwashita, E. G. van Donselaar, V. M. Oorschot, Y. Shimada, T. Fujimoto, H. F. Heijnen, H. J. Geuze and J. W. ...Slot, J Histochem Cytochem 2002; 50: 43–55) to analyze the distribution of cholesterol in the endocytic pathway of human B lymphocytes. We could distinguish 6 categories of endocytic compartments on the basis of morphology, BSA gold uptake kinetics and organelle marker analysis. Of all cholesterol detected in the endocytic pathway, we found 20% in the recycling tubulo‐vesicles and 63% present in two types of multivesicular bodies. In the multivesicular bodies, most of the cholesterol was contained in the internal membrane vesicles, the precursors of exosomes secreted by B cells. Cholesterol was almost absent from lysosomes, that contained the bulk of the lipid bis(monoacylglycero)phosphate, also termed lysobisphosphatidic acid. Thus, cholesterol displays a highly differential distribution in the various membrane domains of the endocytic pathway.
Dipole magnet using permanent magnet technology is under investigation for ILC. It can reduce the cost of electricity for coil excitation and cooling water pump, thick electric cabling and water ...piping, power supply, and their maintenance cost. The structure and the field adjustment scheme of a trial conceptual design will be discussed.
A disk and washer (DAW) coupled cavity linac (CCL) was developed for a mediumvelocity part in a muon linac to measure muon anomalous magentic moment and search for electric dipole moment. Muons were ...accelerated from v/c = β = 0.3 to 0.7 at an operational frequency of 1.3 GHz. In this paper, the cavity design, beam dynamics design, and cold-model measurements are presented.
A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed in 2001 P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001). This scheme has many advantageous ...properties over previously studied focusing schemes, including being significantly shorter for a given energy and having a significantly better energy bandwidth. Experimental results from the ATF2 accelerator at KEK are presented that validate the operating principle of such a scheme by demonstrating the demagnification of a 1.3 GeV electron beam down to below 65 nm in height using an energy-scaled version of the compact focusing optics designed for the ILC collider.
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