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Diagnostics play a very important role in the modern Tokamak where optimum performance is essential. To achieve this, the device must be equipped with reliable and robust sensors and instrumentation that allow the operation envelope to be fully explored. Development of these diagnostics to maintain this reliability is necessary. Further to the development, the systems must be integrated in a way that maintains their performance while simultaneously satisfying the key requirements needed for safety and tokamak operation. ITER will have 50 diagnostics; almost all of which are utilized primarily for the real-time operation of the tokamak. While there is still much work to do, to date, significant progress has been made in the development of these systems. The work load for the developments is shared across all the ITER partners. This paper focuses on the challenges for the integration of the systems.

ITER will explore a plasma parameter envelope currently not available in tokamaks. This will require a set of diagnostics that can follow this envelope. To implement these diagnostics in a reliable and robust way requires development of current techniques in many areas to make them applicable to ITER: they need to be operable in the ITER environment and satisfy the physics and engineering requirements. In some cases, the exploitation of new techniques will be required. While much work has been carried out in this area, significant further work remains to bring the system to implementation.

The microwave absorption properties of M-type hexagonal ferrite BaFe/sub 12-X/(Ti/sub 0.5/Mn/sub 0.5/)/sub X/O/sub 19/ composite have been investigated. It was found that the complex permeability and /spl mu/'/sub r/ and /spl mu/"/sub r/ induced by the ferrimagnetic resonance can be controlled both in amplitude and along the frequency axis by changing the substitution amount x and the powder mixture ratio. The complex permeability of TiMn substituted ferrite composite was successfully adjusted to the calculated absorption condition, and exhibited a wide absorption bandwidth /spl Delta/f/f=47% in the X-band with a homogeneous single-layer configuration. The mixture of two kinds of ferrite powder exhibited a wider bandwidth of 53% and a simulated model indicates that it should be possible to obtain a further increase.

The authors discuss the design and implementation of the authentication system called SPLICE/AS in the WIDE (widely integrated distributed environment) Internet environment. SPLICE/AS is designed based on the public-key encryption, and the authentication scheme originally proposed by R.M. Needham and M.O. Schroeder (1978). In order to manage a large-scale network like WIDE Internet, the hierarchical domain-based management scheme is introduced. Currently, the prototype of SPLICE/AS is working on the 4.3 Berkeley UNIX system. To improve the reliability and robustness of SPLICE/AS, the authors are modifying SPLICE/AS and developing a new protocol for database propagation which is discussed. >