A case report of extrahepatic portal vein aneurysm with thrombosis

Extrahepatic portal vein aneurysm (PVA) is very rare with only 17 previously reported cases. Methods of treatment include resection, thrombectomy, and portal venous decompression. We report herein the first case of large PVA with thrombosis which has been managed without surgical treatment over a long period. A PVA was detected in a 78-year-old woman by abdominal ultrasonography. Computed tomography revealed an aneurysm of 6 cm in a diameter in the porta hepatis. Portal venography showed obstruction of the portal vein and developed collateral vessels around the aneurysm. Since the patient had no symptoms of portal hypertension, we decided to carefully manage her clinical course without surgical treatment. At present, this patient is healthy and has developed no complications over the 5 years since leaving our hospital. This case suggests that surgical treatment is not required for PVA without portal hypertension

Manufacturing and welding assembly of the vacuum vessel on JT-60SA

The JT-60SA Vacuum Vessel (VV) was manufactured as the 10 sectors split in the factory and these sectors were weld-assembled as the 360-degree torus with the design offset value of the weld shrinkage. The dimensions as the 10 m scale torus were well controlled regardless of the thin wall thickness of 18 mm and a large amount of welding line due to the double wall structure and 72 port penetrations. The final VV 20-degree sector was installed into the 340-degree sector of the tokamak with the TF coil and the VV Thermal Shield, and the VV was weld-jointed as a torus. This paper reports the design concept to reduce the safety factor and welding amount to achieve the dimension specified, and the result of the VV manufacturing

Design and manufacturing of thermal shield for JT-60SA

The thermal shield (TS) of JT-60SA which is a superconducting tokamak, is installed to reduce radiation heat load from a vacuum vessel (VV), a cryostat vessel and ports at ambient temperature to superconducting coils at 4 K. The TS is double walled structure with He cooling pipe at 80 K, and is divided electrically in toroidal direction and poloidal direction to suppress eddy currents flowing through the TS during disruption. The TS is required to be installed in a narrow space which is between the VV, the ports, and the superconducting coils. Manufacturing and assembly accuracy of the TS are required to ensure the sufficient space for the relative displacement caused by thermal displacement and seismic load. Customization of mechanical joints in the divided section of the TS is effective process for keeping the required accuracy. Assembly of 340 ° sector of the vacuum vessel thermal shield has been completed

JT-60SA TF magnet assembly

JT-60SA will be the world’s largest superconducting tokamak when it is assembled in 2020 in Naka, Japan(R = 3 m, a = 1.2 m). It is being constructed jointly by institutions in the EU and Japan under the BroaderApproach agreement. The assembly of its 400-tonne toroidalfield (TF) magnet, designed for an on-axisfield of2.25 T, was completed in July 2018. Consideration of its assembly throughout the design process, with asso-ciated consultation and testing, allowed high positional accuracy and hence respect for magneticfield tolerancesto be achieve

Completion of Central Solenoid for JT-60SA

The construction of a magnet system for the tokamak device of JT-60 super-advanced (JT-60SA) was completed inMarch 2020. The manufacturing of central solenoid (CS) had beenfinished in March 2019. The circularity of 4.0 mm is a requirement for CS manufacturing from the point of view of plasma control. The high accurate manufacturing method and jigs had been developed, and the circularity of CS achieves 1.44 mm, which meets the requirement of 4.0 mm. The clearance between the CS and the TF coils is very small, only 14 mm in design. In case the CS touches theTF coils and is subjected to load during operation, the CS can be damaged. Thus the surface dimensions of the CS and the TF coils have been measured before the installation of CS to confirm if the clearance is sufficient large to avoid the CS crashing into the TF coils. The CS was successfully installed to the tokamak center without any damages in December 2019 as the final step of the magnet assembly of JT-60SA. In this paper, the manufacturing results and the installation of the CS are described.Applied Superconductivity Conference 2020 (ASC2020

Development of the thermal insulation devices for the JT-60SA tokamak

This report focuses on the development of the thermal insulation devices including thermal shield (TS) and cryostat for the superconducting tokamak JT-60SA.1. Design, manufacturing and acceptance test were successfully completed by 2019 and installation will be done by March 2020.2. The technique and knowledge to realize high accuracy manufacturing and short time installation of these devices will contribute to the ITER construction and DEMO design.28th IAEAFusion Energy Conferenc