To demonstrate a Mixed Axial and Radial field System (MARS) as the best magnet scheme for future ECRISs, MARS-D, a demonstrative ECRIS using a NbTi MARS magnet is progressing at Lawrence Berkeley National Laboratory. An optimized MARS design can use either NbTi or Nb3Sn coils with reduced engineering complexities to construct the needed high-field magnets. The optimized magnet design could enha...

Both the cogging and electromagnetic torques depends on the shape of the flux density distribution in the airgap region. A two-dimensional (2-D) analytical method for predicting the open- circuit airgap field distribution in brushless permanent magnet motors, considering the direction of magnetization, i.e., radial or parallel, and the effect of real shape of stator slot-openings is presented i...

For self-controlled endoscopes, many kinds of systems have been proposed. Among these, pneumatic actuators show significant potential. However, existing actuators, such as those used in endoscopes, have many weak points. In particular, free movement inside the human intestine is difficult because the diameter of the intestine varies dramatically along its length. We design and test a new method...

This paper describes a solid-cryogen cooling technique currently being developed at the M.I.T. Francis Bitter Magnet Laboratory for application to superconducting magnets of NMR and MRI. The technique is particularly appropriate for “dry” magnets that do not rely on liquid cryogen, e.g., liquid helium (LHe), as their primary cooling sources. In addition, the advantages of a cryocirculator (a co...

Human motion energy harvesting as an alternative to battery powering in body worn and implanted devices is challenging during prolonged periods of inactivity. Even a buffer energy storage system will run out of power eventually if there is no external acceleration to the harvester. This paper presents a method to actuate the rotor inside a previously presented rotational piezoelectric energy ha...

Permanent magnet linear alternators are energy converting devices that have been under research and development for years. This type of alternators have advantages of high efficiency and no need of liner motion to rotation converting, when the driving force is in linear oscillation. Such applications can be found when ocean tide, solar power, and swing motions are used for generating electric p...

MR is undoubtedly the most revolutionary imaging technology of the century. The clinical jsefulness of MRI has been widely accepted in the CNS, spine and certain body areas and the future vision of MR includes wide-ranging morphological and functional applications in cardiology, oncology, orthopaedics, obstetrics and sports medicine. In order to accommodate this wide range of clinical applicati...

one of the main problems in wind energy conversion system (wecs) is how to achieve maxim­u­m output power in different wind speeds. maximum methods for maximum power point tracking in wind energy conversion syst­e­ms require the knowledge of system characteristics and mechanic sensors. so, using these methods practically will follow with high price and an abundant difficulties. in this paper, n...

The development procedure of permanent magnet drives for sensor less operation beginning from standstill under overload conditions has to consider different design aspects coevally. First, the robust rotor position sensing by test signal enforces a design with a strongly different behavior of the spatial dq-oriented differential inductance values. Therefore, the interior rotor magnet array arra...

Using the method of separate variables, the three-dimensional magnet field solution expressed in Fourier’s expansion for permanent magnet (PM) machines with finite axial magnet length is presented in this paper. From the analytic results obtained, much useful and interesting design information for PM machines in three dimensions may be quantitatively deduced. Design curves of the leakage factor...