Thermally modified C-band acceleration unit for a high-repetition normal-conducting linac for free-electron lasers.

A high-repetition linear accelerator with multibeamline operation for X-rays allows users to perform multiple simultaneous experiments with an X-ray free-electron laser (XFEL) at lower actual cost per user while maintaining the availability of the laser. As the first step toward a higher pulse repetition rate (PRR), we developed radio frequency (RF) components at 5712 MHz and tested them for their feasibility at an RF PRR of 120 pulses per second (pps). To increase the RF PRR from the present value of 60 pps-at the SPring-8 Angstrom compact free-electron laser-to 120 pps, we re-examined the thermal designs of the present RF components for the XFEL. With the proposed design, the newly developed RF components worked well at 120 pps. The insulation-oil temperature in the high-voltage tank of the klystron modulator was below 70 °C, which is less than the operational temperature limit. At 5712 MHz, this is now the highest RF pulse repetition frequency yet to be achieved and represents a major step toward higher PRRs.

A stable pulsed power supply for multi-beamline XFEL operations.

Since an X-ray Free Electron Laser (XFEL) facility is a linac-based single-user machine, a multi-beamline mode of operation, which improves the efficiency of user experiments, is critical for accommodating users' rapidly increasing demand for beamtime. A key supporting technology is a highly stable pulsed power supply (PS), which enables stable XFEL operations by precisely switching the beam route. We developed a high-power pulsed PS to drive a kicker magnet installed in a SACLA's beam switching system. SiC MOSFETs were adapted as switching elements to reduce the required size and to increase the electric power efficiency. The PS we developed provides two key capabilities: (i) a high current stability of 20 ppm (peak-to-peak) at a peak power of 0.24 MW and (ii) generation of controllable, bipolar, and trapezoidal current waveforms at 60 Hz. This paper describes the overall concept, the detailed design, the performance achieved, and the initial beam test results.

Population health and regional variations of disease burden in Japan, 1990-2015: a systematic subnational analysis for the Global Burden of Disease Study 2015.

BACKGROUND: Japan has entered the era of super-ageing and advanced health transition, which is increasingly putting pressure on the sustainability of its health system. The level and pace of this health transition might vary across regions within Japan and concern is growing about increasing regional variations in disease burden. The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015) provides a comprehensive, comparable framework. We used data from GBD 2015 with the aim to quantify the burden of disease and injuries, and to attribute risk factors in Japan at a subnational, prefecture-level. METHODS: We used data from GBD 2015 for 315 causes and 79 risk factors of death, disease, and injury incidence and prevalence to measure the burden of diseases and injuries in Japan and in the 47 Japanese prefectures from 1990 to 2015. We extracted data from GBD 2015 to assess mortality, causes of death, years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life-years (DALYs), life expectancy, and healthy life expectancy (HALE) in Japan and its 47 prefectures. We split extracted data by prefecture and applied GBD methods to generate estimates of burden, and attributable burden due to known risk factors. We examined the prefecture-level relationships of common health system inputs (eg, health expenditure and workforces) to the GBD outputs in 2015 to address underlying determinants of regional health variations. FINDINGS: Life expectancy at birth in Japan increased by 4·2 years from 79·0 years (95% uncertainty interval [UI] 79·0 to 79·0) to 83·2 years (83·1 to 83·2) between 1990 and 2015. However, the gaps between prefectures with the lowest and highest life expectancies and HALE have widened, from 2·5 to 3·1 years and from 2·3 to 2·7 years, respectively, from 1990 to 2015. Although overall age-standardised death rates decreased by 29·0% (28·7 to 29·3) from 1990 to 2015, the rates of mortality decline in this period substantially varied across the prefectures, ranging from -32·4% (-34·8 to -30·0) to -22·0% (-20·4 to -20·1). During the same time period, the rate of age-standardised DALYs was reduced overall by 19·8% (17·9 to 22·0). The reduction in rates of age-standardised YLDs was very small by 3·5% (2·6 to 4·3). The pace of reduction in mortality and DALYs in many leading causes has largely levelled off since 2005. Known risk factors accounted for 34·5% (32·4 to 36·9) of DALYs; the two leading behavioural risk factors were unhealthy diets and tobacco smoking in 2015. The common health system inputs were not associated with age-standardised death and DALY rates in 2015. INTERPRETATION: Japan has been successful overall in reducing mortality and disability from most major diseases. However, progress has slowed down and health variations between prefectures is growing. In view of the limited association between the prefecture-level health system inputs and health outcomes, the potential sources of regional variations, including subnational health system performance, urgently need assessment. FUNDING: Bill & Melinda Gates Foundation, Japan Ministry of Education, Science, Sports and Culture, Japan Ministry of Health, Labour and Welfare, AXA CR Fixed Income Fund and AXA Research Fund.

Extreme ultraviolet free electron laser seeded with high-order harmonic of Ti:sapphire laser.

The 13th harmonic of a Ti:sapphire (Ti:S) laser in the plateau region was injected as a seeding source to a 250-MeV free-electron-laser (FEL) amplifier. When the amplification conditions were fulfilled, strong enhancement of the radiation intensity by a factor of 650 was observed. The random and uncontrollable spikes, which appeared in the spectra of the Self-Amplified Spontaneous Emission (SASE) based FEL radiation without the seeding source, were found to be suppressed drastically to form to a narrow-band, single peak profile at 61.2 nm. The properties of the seeded FEL radiation were well reproduced by numerical simulations. We discuss the future precept of the seeded FEL scheme to the shorter wavelength region.

Mycotic abdominal aneurysm caused by campylobacter fetus: a case report for surgical management.

We report a rare case of mycotic abdominal aortic aneurysm associated with Campylobacter fetus. A 72-year-old male admitted to the hospital because of pain in the right lower quadrant with pyrexia. The enhanced abdominal computed tomography (CT) examination showed abdominal aortic aneurysm (AAA) measuring 50 mm in maximum diameter and a high-density area of soft tissue density from the right lateral wall to the anterior wall of the aorta. However, since the patient showed no significant signs of defervescence after antibiotics administration, so we performed emergency surgery on the patient based on the diagnosis of impending rupture of mycotic AAA. The aneurysm was resected in situ reconstruction using a bifurcated albumin-coated knitted Dacron graft was performed. The cultures of blood and aneurysmal wall grew Campylobacter fetus, allowing early diagnosis and appropriate surgical management in this case, and the patient is making satisfactory progress. This is the fifth report of mycotic AAA characterizing culture positive for Campylobacter fetus in blood and tissue culture of the aortic aneurysm wall.