Oscillations of the orbital magnetic moment due to d-band quantum well states

The effect of electron confinement on the magnetocrystalline anisotropy of ultrathin bcc Fe films is explored by combining photoemission spectroscopy, x-ray magnetic circular dichroism, and magneto-optical Kerr effect measurements. Pronounced thickness-dependent variations in the magnetocrystalline anisotropy are ascribed to periodic changes in the density of states at the Fermi level, induced by quantization of d(xz), d(yz) out-of-plane orbitals. Our results reveal a direct correlation between quantum well states, the orbital magnetic moment, and the magnetocrystalline anisotropy.

Continuous Chitosan Hydrolyzate Production by Immobilized Chitosanolytic Enzyme fromEnterobactersp. G-1

Chitosanolytic enzymes from Enterobacter sp. G-1 were immobilized on various carriers to continuously hydrolyze chitosan. Four different carriers were tested: FE-3901 (strong basic anion exchange resin, ionic binding), glutaraldehyde-treated FE-4612 (weak basic anion exchange resin, cross-linking), Chitopearl (chitosan beads), and alginate calcium. Glutaraldehyde-treated FE-4612 and Chitopearl immobilized more protein than the others. The enzyme immobilized on FE-3901 had the greatest activity. The activity of enzyme immobilized on FE-3901 decreased rapidly when exposed to a continuous flow of 1% chitosan. The enzyme immobilized with Chitopearl retained more than 50% of its original activity after 17 days, and the activity was fully restored by re-immobilization.

Implementation of an operator intervention system for remote control of the RIKEN 28 GHz superconducting electron cyclotron resonance ion source

The control system for the RIKEN 28 GHz superconducting electron cyclotron resonance ion source (28 GHz SC-ECRIS) consists of a distributed control system based on the experimental physics and industrial control system. To maintain the beam quality for the long beam-service time at the radioactive isotope beam factory, beam tuning to prevent subtle changes in the 28 GHz SC-ECRIS conditions is required. Once this is achieved, it should then be possible to check conditions and operate the ion source at any time. We have designed a web-based operational interface to remotely control the ion source, but for access and control from several locations, suitable access security, policies, and methods are required. We thus implemented an operator intervention system that makes it possible to safely access the network externally with the permission of on-site accelerator operators in the control room.

Recent development of RIKEN 28 GHz superconducting electron cyclotron resonance ion source

Over the past two years, we have tried to improve the performance of the RIKEN superconducting electron cyclotron resonance ion source using several methods. For the production of U vapor, we chose the sputtering method because it is possible to install a large amount of material inside the plasma chamber and thus achieve long-term operation without a break, although it is assumed that the beam intensity is weaker than in the oven technique. We also used an aluminum chamber instead of a stainless steel one. Using these methods, we successfully produced ∼180 eμA of U(35+) and ∼230 eμA of U(33+) at the injected radio frequency (RF) power of ∼4 kW (28 GHz). Very recently, to further increase the beam intensity of U(35+), we have started to develop a high temperature oven and have successfully produced a highly charged U ion beam. In this contribution, we report on the beam intensity of highly charged U ions as a function of various parameters (RF power and sputtering voltage) and discuss the effects of these parameters on the beam stability in detail.

Review of highly charged heavy ion production with electron cyclotron resonance ion source (invited)

The electron cyclotron resonance ion source (ECRIS) plays an important role in the advancement of heavy ion accelerators and other ion beam applications worldwide, thanks to its remarkable ability to produce a great variety of intense highly charged heavy ion beams. Great efforts over the past decade have led to significant ECRIS performance improvements in both the beam intensity and quality. A number of high-performance ECRISs have been built and are in daily operation or are under construction to meet the continuously increasing demand. In addition, comprehension of the detailed and complex physical processes in high-charge-state ECR plasmas has been enhanced experimentally and theoretically. This review covers and discusses the key components, leading-edge developments, and enhanced ECRIS performance in the production of highly charged heavy ion beams.

Development of a high-temperature oven for the 28 GHz electron cyclotron resonance ion source

We have been developing the 28 GHz ECR ion source in order to accelerate high-intensity uranium beams at the RIKEN RI-beam Factory. Although we have generated U(35+) beams by the sputtering method thus far, we began developing a high-temperature oven with the aim of increasing and stabilizing the beams. Because the oven method uses UO2, a crucible must be heated to a temperature higher than 2000 °C to supply an appropriate amount of UO2 vapor to the ECR plasma. Our high-temperature oven uses a tungsten crucible joule-heated with DC current of approximately 450 A. Its inside dimensions are ϕ11 mm × 13.5 mm. Since the crucible is placed in a magnetic field of approximately 3 T, it is subject to a magnetic force of approximately 40 N. Therefore, we used ANSYS to carefully design the crucible, which was manufactured by machining a tungsten rod. We could raise the oven up to 1900 °C in the first off-line test. Subsequently, UO2 was loaded into the crucible, and the oven was installed in the 28 GHz ECR ion source and was tested. As a result, a U(35+) beam current of 150 μA was extracted successfully at a RF power of approximately 3 kW.

Operational test of micro-oven for 48Ca beam

In order to supply a high-intensity and stable (48)Ca beam from the RIKEN 18-GHz electron cyclotron resonance ion source, we are conducting operational tests of a micro-oven. A mixture of CaO and Al powders is placed into the crucible of the micro-oven and heated to produce metallic calcium by a reductive reaction. The successful production of a calcium beam was confirmed. In addition, we reduced the material consumption rate by using a so-called "hot liner," and we enhanced the beam intensity by applying a negative voltage bias to the micro-oven, the effect of which is similar to the effect of a "biased disk."

Exercise capacity in relation to autoantibodies in systemic sclerosis patients

Autoantibodies have been detected in systemic sclerosis patients, and typical clinical features regarding organ involvement by each autoantibody have been reported. To reveal differences in exercise intolerance in patients with either anti-topoisomerase-I or anti-centromere antibodies, 53 systemic sclerosis patients were investigated retrospectively. A 6-min walking distance showed no significant differences (P = 0.090) between autoantibodies, while exercise-induced hypoxia during the 6-min walking test was significant in subjects with the anti-topoisomerase-I antibody (P = 0.033). The percent predicted of vital capacity, the diffusion capacity of the lung for carbon monoxide, and the modified Rodnan skin score were affected more in subjects with the anti-topoisomerase-I antibody than the anti-centromere antibody. The main parameter affecting the 6-min walking distance was the percent predicted of vital capacity for each autoantibody, and there was a significant positive relationship for all subjects (R² = 0.30, P < 0.0001). Exercise-induced hypoxia was also shown in the more affected subjects in the percent predicted of vital capacity and the diffusion capacity of the lung for carbon monoxide. Lung parameters were suggested to be more important factors determining exercise intolerance and induced hypoxia than detected autoantibodies.

Development of very small-diameter, inductively coupled magnetized plasma device

In order to miniaturize a high-density, inductively coupled magnetized plasma or helicon plasma to be applied to, e.g., an industrial application and an electric propulsion field, small helicon device has been developed. The specifications of this device along with the experimental results are described. We have succeeded in generating high-density (~10(19) m(-3)) plasmas using quartz tubes with very small diameters of 10 and 20 mm, with a radio frequency power ~1200 and 700 W, respectively, in the presence of the magnetic field less than 1 kG.

Quality evaluation of spaceborne SiC mirrors (II): evaluation technology for mirror accuracy using actual measurement data of samples cut out from a mirror surface

The authors studied the quality evaluation technology of a spaceborne large-scale lightweight mirror that was made of silicon carbide (SiC)-based material. To correlate the material property of a mirror body and the mirror accuracy, the authors evaluated the mirror surface deviation of a prototype mirror by inputting actually measured coefficient of thermal expansion (CTE) data into a finite element analysis model. The CTE data were obtained by thermodilatometry using a commercial grade thermal dilatometer for the samples cut from all over the mirror surface. The computationally simulated contour diagrams well reproduced the mirror accuracy profile that the actual mirror showed in cryogenic testing. Density data were also useful for evaluating the mirror surface deviation because they had a close relationship with the CTE.

Clinical outcomes of endoscopic resection for nonampullary duodenal high-grade dysplasia and intramucosal carcinoma

This study retrospectively analyzed the clinical outcomes of endoscopic resection of 26 sporadic (i. e., not associated with polyposis syndrome) nonampullary duodenal lesions representing high-grade dysplasia or intramucosal carcinoma (duodenal HGD/IMC) in 23 patients. No severe complications such as perforation were observed, but three cases of delayed bleeding were seen. The use of endoscopic clips significantly decreased the delayed bleeding rate (0/19, 0%) compared with cases in which clips were not used (3/7, 42.9%; P = 0.013, χ2 test). Eighteen lesions (69.2%) were removed by en bloc resection. The follow-up period after resection was 25.5 ± 23.3 months. Two lesions (7.7%) that recurred locally were detected at the first surveillance endoscopy 3 months after resection. These lesions were 22 and 15 mm in size respectively and were resected piecemeal. Endoscopic resection is an effective and safe procedure for treating duodenal HGD/IMC. En bloc resection and prophylactic clip usage are encouraged.