Design of the central region in the Gustaf Werner cyclotron at the Uppsala university

This paper describes the design of the central region in the Gustaf Werner cyclotron for h=1, 2 and 3 modes of acceleration. The electric field distribution in the inflector and in the four acceleration gaps has been numerically calculated from an electric potential map produced by the program RELAX3D. The geometry of the central region has been tested with the computations of orbits carried out by means of the computer code CYCLONE. The optical properties of the spiral inflector and the central region were studied by using the programs CASINO and CYCLONE, respectively.     

Automated liquid injection field desorption/ionization for Fourier transform ion cyclotron resonance mass spectrometry

We describe automation of liquid injection field desorption/ionization (LIFDI) for reproducible sample application, improved spectral quality, and high-throughput analyses. A commercial autosampler provides reproducible and unattended sample application. A custom-built field desorption (FD) controller allows data station or front panel control of source parameters including high-voltage limit/ramp rate, emitter heating current limit/ramp rate, and feedback control of emitter heating current based on ion current measurement. Automated LIFDI facilitates ensemble averaging of hundreds of Fourier transform ion cyclotron resonance mass spectra for increased dynamic range, mass accuracy, and S/N ratio relative to single-application FD experiments, as shown here for a South American crude oil. This configuration can be adapted to any mass spectrometer with an LIFDI probe.     

The axial propagation of plasma upon radial injection in a current interrupter

The axial propagation of plasma in a current interrupter with radial injection guns has been experimentally studied. In the absence of a generator current passing through the injected plasma, the plasma front with a density of no less than 10¹¹ cm^?3 moves in the axial direction at a velocity of ～(1–1.5)×10⁷ cm/s. At a distance of 20 cm from the injection plane, a plasma density of ～10¹³ cm^?3 is attained 5–6 ms after the current switch on in the guns; at a distance of 50 cm, the plasma density reaches ～(2–5)×10¹² cm^?3.     

A storage ring for the JULIC cyclotron

The storage ring COSY is planned to provide higher intensity and resolution for nuclear structure experiments using the light heavy ion beams (p, d, τ, α) of the JULIC cyclotron and the magnet spectrograph BIG KARL. The ring contains the measuring target of BIG KARL as an internal target, two rf cavities for compensating the mean energy loss in the target and providing additional acceleration of the stored beam and an e^?-cooling section. In the recirculator mode, i.e., without e^?-cooling, a luminosity of L = 3.64 × 10³⁰ particles/(cm² s) is obtained for an experiment with 41 MeV protons and a 50 μg/cm²¹²C target at a spectrograph resolution p/dp = 10⁴ and 100% duty factor. This corresponds to a gain in L of 546.5 in comparison with the same experiment without a storage ring. In the recirculator mode with acceleration L = 1.17 × 10³² p/(cm² s) and 98.8% duty factor results for 1500 MeV protons on the same target at the same resolution. Using e^?-cooling L and the feasible p/dp can be enhanced, however, at a reduced duty factor.     

纯水轴向柱塞泵滑履的静压支承设计

 对纯水轴向柱塞泵滑履摩撩副的最佳水膜厚度进行了计算和分析．结果表明．纯水轴向柱塞泵滑履摩擦副不宜采用完全平衡型静压支承设计． 对纯水轴向柱塞泵滑履的结构参数和材料进行了设计分析．     

Calculation of the motion of gases and heat transfer in the axial region of a cyclonic flow

Methods are presented for calculating distributions of tangential velocity and static pressure and the lengthwise and radial heat transfer in the axial zone of a cyclonic flow.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 47, No. 6, pp. 892–903, December, 1984.     

Design of hat-stiffened composite panels loaded in axial compression

An integrated step-by-step analysis procedure for the design of axially compressed stiffened composite panels is outlined. The analysis makes use of the effective width concept. A computer code, BUSTCOP, is developed incorporating various aspects of buckling such as skin buckling, stiffener crippling and column buckling. Other salient features of the computer code include capabilities for generation of data based on micromechanics theories and hygrothermal analysis, and for prediction of strength failure. Parametric studies carried out on a hat-stiffened structural element indicate that, for all practical purposes, composite panels exhibit higher structural efficiency. Some hybrid laminates with outer layers made of aluminium alloy also show great promise for flight vehicle structural applications.     

Beam attenuator for the LBL 88 inch cyclotron

A beam attenuator has been installed on the ECR injection line for the LBL 88 in. cyclotron, which gives fast attenuation of the beam by factors ranging from 2 to 4 × 10⁹.     

Centering of the ion trajectory in the cyclotron

In this paper we present the theory of the horizontal motion ions through the acceleration gap in the case of a static magnetic field and time-varying electric field. It also describes the motion of the center of the ion trajectory through the acceleration gap and also during the acceleration process. The result also describes analytically the angle through which the ion passed (so called “flying angle”) between two acceleration gaps. That angle can be measured from the center of the ion trajectory or from the center of the cyclotron. The analysis shows that the “flying angle” of the ions measured in these two reference systems is not same. Namely, the “flying angle” of the ion measured from the center of its trajectory is bigger than in the case when the “flying angle” is measured from the center of the cyclotron. It shows that difference between “flying angle” in these two reference systems becomes less and less during acceleration process.     

涡旋式压缩机轴向柔性补偿机构设计

介绍涡旋式压缩机轴向柔性补偿机构的原理、设计流程、设计实例以及测试结果，同时针对高压式设计与中压式设计对压缩机运转范围的影响作一比较，为设计者、使用者与有兴趣的读者提供参考。     

Targetry for the cyclotron production of short-lived radionuclides for medical use

Solid, liquid and gas targets for the production of short-lived radionuclides for medical use are discussed: liquid and gas targets have important advantages compared to solid targets. Target systems for the production of ¹¹C, ¹³N, ^15O, ³⁸K and ⁸¹Rb and the experimental optimization of gas target systems are described.     

The central region of the PbO/TeO2 phase diagram

This work constitutes a closer investigation of part of the system, PbO/TeO₂, with particular attention to the existence and nature of a 11 molar ratio compound, following inconsistencies in previous publications. Observations on previous attempts to pull crystals from the melt are reconsidered in the light of the current work.     

Design and fabrication of gypsum mold for injection molding

Traditionally, a mold made of gypsum can only be used in a low-pressure molding, e.g. casting, due to the weak strength of gypsum material. This study addresses the potential of gypsum as a candidate for rapid tooling used in injection molding. The ingredients for the gypsum mold were decided upon, and an additional compression with a vibration process was introduced to enhance the mechanical strength of the gypsum mold. Scanning electron microscope (SEM) results show that the amount of void inside the gypsum mold is reduced, and more interlocking of the microstructure of gypsum is formed by increasing the intensity of the compression with a vibration process. A higher degree of interlocking produces a significant enhancement of the compressive strength of the gypsum. Two samples were selected as master designs for testing the replication performance and lifetime of the gypsum mold. The dimensional replication accuracy of the molded part was over 99.9%. The maximum lifetime of the gypsum mold is about 210 cycles of injection shots. This work provides an alternative tooling for injection molding that can allow manufacturers to produce a small quantity of prototypes in an efficient and cost-effective way in the early stages of product development.     

中性束注入系统热测靶设计

介绍了中性束注入系统热测靶的测量原理,提出了热测靶的设计方案,并对测量误差进行了分析,介绍了中性束注入系统束线上束流功率和功率密度分布的测量方法,对中性束注入系统也作了简单介绍.     

The effects of side walls on axial flow in rectangular ducts with suction and injection

Summary.  The effects of the side walls on the flows in ducts with suction and injection are examined. Three illustrative examples are considered. The first example considers the effect of the side walls on the flow over a porous plate. It is shown that the presence of the side walls provides a solution for both injection and suction, although, in the absence of the side walls, a solution exists only in the case of suction. The second example considers the flow between two porous plates and the third example the flow in a rectangular duct with two porous walls. Analytical solutions are obtained for the velocity, the volume flux across a plane normal to the flow and the vorticity. In order to show the effects of the side walls for the flow on a rectangular duct, a comparison of these quantities with those in the flow between two parallel porous plates is established. These three examples show that there are pronounced effects of the side walls on the flows in ducts with suction and injection. Received January 10, 2002; revised September 27, 2002 Published online: May 8, 2003 The author is grateful to Prof. D. Poulikakos for his suggestions and to a referee for careful corrections of an earlier version of this paper.     

Design and implementation of a portable computerized axial tomography system for field use

A prototype, portable computerized axial tomography (CAT) scanner for in-field use has been designed, built and tested by researchers at the University of Missouri — Columbia. The device weighs 24 kg (53 lbs), is battery-powdered (providing eight hours of use without recharge), and fits into two small suitcases. A typical scan provides a low resolution (1.0 cm) image of an object 30 cm (12 in.) in diameter with a density of 0.65 g/cm³ in eight minutes of imaging and data reconstruction time. The resulting image is displayed in the field on the system's portable computer system.     

Design of axial flow fans with high aerodynamic loading

Three blading designs of high pressure ratio axial flow fan with hub/tip ratio of 0.7 were carried out with the use of compressor design technology. The flow coefficient and/or pressure coefficient moved in the range of 0.4 to 0.65 and/or 0.65 to 0.85. In the design computations own secondary losses data were applied. The blading tests proved maximum efficiency over 90% in all variants. The measured values of fan stage pressure coefficient were higher than the theoretical ones at design conditions. It consists in a lower rotor deviation angles in contrast to the design. Therefore some ampirical dependencies were derived.