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Diurnal variation of precipitation is a fundamental periodic signal of local climate. Comprehensive study of diurnal variation of precipitation is helpful in studying the formation of local climate and validating satellite precipitation products. In this study, a comparison is drawn between precipitation gauge observations and Tropical Rainfall Measuring Mission (TRMM) 3B42 data on diurnal variation of precipitation. First, using the K-means clustering algorithm, stations with gauge observations and pixels with TRMM data are divided into different groups according to the diurnal variation of precipitation, respectively. In each group, the stations have similar diurnal variation of precipitation. Then maps of diurnal variation of precipitation for gauge observations and TRMM data are obtained. According to these maps, the diurnal variation of precipitation over the contiguous United States (CONUS) presents seasonal variability in both gauge observations and TRMM data. In addition, the diurnal variation of precipitation shows clustered features in space. However, the spatial patterns of the obtained maps do not match, and the TRMM satellite data perform poorly in capturing the hourly precipitation event. Finally, the possible mechanism behind the prevailing nocturnal precipitation over the middle of the CONUS is discussed, with the prevailing nocturnal precipitation judged likely to be strongly related to the mountain-plains solenoid (MPS) circulation. [ABSTRACT FROM AUTHOR]

• Electrical performance of ITER CS prototype joints. • Detailed destructive examination of ITER prototype joints: twin – box and coaxial. • Explanation of the difference in performance based on the destructive examinations. The ITER Magnet System will be the largest and most challenging integrated superconducting magnet system ever built. For the Central Solenoid (CS), cable – in – conduit - conductors (CICCs) of nearly one kilometre length are produced, but still, it will be necessary to connect several lengths together to wind the gigantic 110 tonnes coils. The creation of these superconducting joints is one of the most delicate parts of the assembly. There are three types of ITER CS joints: splice joints, coaxial joints and twin – box joints. US ITER, the ITER Domestic Agency of the USA produced a prototype containing all three types of joints. The goal is to test the performance of the joints in the SULTAN facility of the Swiss Plasma Center (SPC), capable of reproducing close – to – service conditions: high magnetic field (up to 11 T background field), high current (up to 100 kA) and high mass flow rate of supercritical helium for cooling. The paper describes the results of a comprehensive examination campaign aimed at understanding the relation between fabrication and performance of the CS prototype joints. The test campaign combines advanced image analysis for the assessment of the void fraction of the conductors with Scanning Electron Microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) to evaluate the quality of the contact between the strands and the sleeve / sole of the joints. [ABSTRACT FROM AUTHOR]

Abstract: The United States ITER Project Office (USIPO) is responsible for fabrication of the Central Solenoid (CS) for International Thermonuclear Experimental Reactor (ITER). The CS Insert (CSI) project should provide a verification of the conductor performance in relevant conditions of temperature, field, currents and mechanical strain. The US IPO will build the CSI that will be tested at the Central Solenoid Model Coil (CSMC) Test Facility at JAEA, Naka. One of the design goals of the CSI is to assure that the properties of the conductor near the median plane are measured accurately. Since Nb3Sn is strain sensitive and electromagnetic forces generate a significant strain that increases the current sharing temperature (T cs), we need to design the Insert in such a way that the most strained conductor near the median plane would still have the lowest T cs of all the rest of the conductor in the Insert. The difference between thermal contraction of the jacket and spacer material allows controlling axial distribution of the coil radial deformation. Numerical analysis of the CSI was performed using stainless steel, titanium and invar spacer material variants. Distribution of the T cs was obtained from numerical results in the form similar to one proposed for ITER. [Copyright &y& Elsevier]

The United States ITER Project Office (USIPO) is responsible for fabrication of the Central Solenoid (CS) for International Thermonuclear Experimental Reactor (ITER). The CS Insert (CSI) project should provide verification of the conductor performance in relevant conditions of temperature, field, currents and mechanical strain. The USIPO will build the CSI that will be tested at the Central Solenoid Model Coil (CSMC) Test Facility at JAEA, Naka, Japan. This paper presents three-dimensional mathematical model of CSI based on the design. Simulations were performed in order to verify structural integrity and compliance with the Japanese High Gas Pressure Safety Law. Numerical simulations lead to the design of the CSI that produced a required strain levels during operation on the superconductor cable, while simultaneously satisfy the ITER magnet structural design criteria. [ABSTRACT FROM PUBLISHER]

Abstract: The paper presents the status of research and development (R&D) magnet tasks that are being performed in support of the U.S. ITER Project Office (USIPO) commitment to provide a central solenoid assembly and toroidal field conductor for the ITER machine to be constructed in Cadarache, France. The following development tasks are presented: winding development, inlets and outlets development, internal and bus joints development and testing, insulation development and qualification, vacuum-pressure impregnation, bus supports, and intermodule structure and materials characterization. [Copyright &y& Elsevier]

Abstract: The U.S. Heavy Ion Fusion program is developing superconducting focusing quadrupoles for near-term experiments and future driver accelerators. Following the fabrication and testing of several models, a baseline quadrupole design was selected and further optimized. The first prototype of the optimized design has achieved a conductor-limited gradient of 132T/m in a 70mm bore, with measured field harmonics within 10 parts in 104. In parallel, a compact focusing doublet was fabricated and tested using two of the first-generation quadrupoles. After assembly in the cryostat, both magnets reached their conductor-limited quench current. Further optimization steps are currently underway to improve the performance of the magnet system and reduce its cost. They include the fabrication and test of a new prototype quadrupole with reduced field errors as well as improvements of the cryostat design for the focusing doublet. The prototype focusing units will be installed in the HCX beamline at LBNL, to perform accelerator physics experiments and gain operational experience. Successful results in the present phase will make superconducting magnets a viable option for the next generation of integrated beam experiments. [Copyright &y& Elsevier]

Focuses on the development of an Nb3Sn conductor joint for the Central Solenoid (CS) Model Coil of the International Thermonuclear Experimental Reactor. Configuration of the butt joint for the CS Model Coil; Fabrication of hairpin cable; Joint resistance; Measurement of the quench current in various temperatures and fields.

Evaluates the performance of the coils made of Cable-In-Conduit Nb3Sn conductors for the Central Solenoid of the International Thermonuclear Experimental Reactor. Performance of fast ramp tests; Distribution of the current inside the cable; Measurement of the critical current; Determination of the fastest possible current ramps.

Focuses on the use of the pancake-wound technique in the development of the central solenoid (CS) coil of the Reduced Technical Objective/Reduced Cost for the International Thermonuclear Experimental Reactor. Coil design; Two alternatives for the CS conduit reinforcement; Assessment of the CS structure performance through an axisymmetric finite element method.

Describes the design and fabrication of an Central Solenoid Model Coil developed by the International Thermonuclear Experimental Reactor. Overview of the inner module fabrication; Peak field produced by the model coil; Coil winding procedure; Insulation technology and materials.

Reports on the completed fabrication of the Central Solenoid model coil's outer module developed by the International Thermonuclear Experimental Reactor. Eight layers consisting the outer module; Vacuum epoxy impregnation; Instrumentation; Criteria for the final inspection.

Describes the fabrication process involved in the Central Solenoid (CS) model coil program of the International Thermonuclear Experimental Reactor international collaboration and which was completed on May 1999. Fabrication of the CS insert coil; Helical winding; Terminal fabrication; Heat treatment procedure; Critical temperature test; Turn and ground insulation.

Reports on the design, fabrication and testing program of the BABAR superconducting solenoid in the PEP-II B-Factory machine at the Stanford Linear Accelerator Center in Menlo Park, California. Description of the solenoid; Critical current measurements of the superconducting strand, cable and conductor and magnetic forces.

Describes the development of the third generation electron cyclotron resonance ion source in Berkeley, California. Combination of ion source techniques enhancing high charge state ion production; Evaluation of the prototype superconducting magnet structure; Effect of the solenoids on the operation of sextupole coils.

The U.S. Army and Navy have jointly sponsored the preparation of a draft report entitled "Handbook of Reliability Prediction Procedures for Mechanical Equipment." The draft handbook has been prepared by Eagle Technology Inc., of 2300 South Ninth Street, Arlington, Virginia 22204, U.S.A. It includes failure rate models for seals, springs, solenoids, valve assemblies, bearings, gears and splines, actuators, pumps, filters, and brakes and clutches. The failure rate models are all based on a constant failure rate assumption, and independence of failures, despite the statement in the introduction that the processes that lead to failure are time-dependent. Also, the models developed are somewhat complex.