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A neutron source for material and component tests is an essential tool for the DEMO reactor development. An accelerator-based neutron source such as IFMIF is regarded as the most promising one in Japan and the EU. The construction plan of IFMIF is still open due to the influence of the large cost overrun of ITER procurements. Japan Atomic Energy Agency (JAEA) has a plan of a neutron source for material and component tests using an IFMIF/EVEDA prototype accelerator and a lithium test loop for the IFMIF target facility. Expected performances of three options; 9 MeV and upgrading to 26 or 40 MeV of deuteron beam, are discussed. At the back plate position of the target, 1.5, 14, and 25 dpa/fpy are expected for 9, 26, and 40 MeV case, respectively. The option of 40 MeV is desirable, however, the option of 26 MeV is acceptable for blanket functional tests and material tests.

Based on long-term research activities on fusion engineering, eleven key technologies for future fusion reactors, especially for demo reactor, were selected in the Working Group of fusion research under the Council for Science and Technology, MEXT.In this paper, the recent achievement on the following key technologies will be summarized, which are strongly related to the Working Group proposal, 1) Fusion engineering research project in National Institute for Fusion Science, 2) High Tc superconducting magnets, 3) LiPb blanket system 4) Tungsten divertor and 5) Fusion engineering activities under the Broader Approach (BA) framework.

AbstractFusion product diagnostics can be used to determine a fusion reaction rate, which indicates how close the plasma is to the ultimate goal of making a power plant based on nuclear fusion. However, these diagnostics can also provide large amounts of additional information, such as ion temperatures, the thermonuclear fraction in the fusion reaction rate, degree of fast ion confinement, fast ion loss mechanism, etc. Measurement systems for fusion product diagnostics are usually designed and optimized to a specific performance so that they play different roles in the experiment. The neutron emission rate, which is directly related to the fusion output, can be determined by (a) time-resolved emission monitors, which are well calibrated onsite, in combination with (b) activation systems and (c) profile monitors with accuracy up to several percent. The time-resolved neutron profiles also provide useful information for transport analysis. Velocity distributions and confinement properties of fast ions can be obtained from (d) the neutron spectrometers and (e) gamma-ray measurement. The interaction between plasma dynamics and fast ions can be studied with most fusion product diagnostic systems, especially with (f) escaping charged fusion product detectors. Each section of this chapter contains a general explanation of these systems, showing some experimental results obtained on present devices. A lot of interesting and useful information on the behavior of energetic particles and their degree of confinement are provided by them because interaction between thermal and nonthermal energetic ions and that among nonthermal ions contribute dominantly to the fusion reaction rate in present deuterium-deuterium experiments. In future deuterium-tritium fusion experiments on ITER, the contribution of thermonuclear fraction will be increased, and the combination of several neutron measurement systems will provide the absolute fusion output and neutron fluence on the first wall. Together with neutron measurement, alpha particle and gamma-ray measurement play important roles in research on self-heating burning plasma physics and hence in the burning control of the device.

AbstractA series of irradiation experiments were performed using Fusion Neutronics Source (FNS) at JAEA for the investigation of activation of materials relevant to Lithium/vanadium-alloy and Flibe/vanadium-alloy blankets. The specimens of V-4Cr-4Ti, Er and Teflon in 10 mm×10 mm×0.03-0.1 mm were prepared for studying the activation of V-alloy structure, MHD coating of Er2O3, and F in molten salt Flibe, respectively. Be, Li and Li/Be mock-ups were assembled with Be and solid Li blocks in addition to the assembly for direct D-T neutron irradiation to examine the dependence of the activation on neutron spectrum. The neutron spectra in all irradiation locations were calculated using MCNP code and JENDL-3.3 file. The activities of the specimens induced in various neutron fields were measured with a high purity Ge detector (HP-Ge). Experimental analyses were carried out using FISPACT-2001 codes with both EAF-2001 file and FENDL/A-2.0 & FENDL/D-2.0 libraries. The typical calculation/experiment (C/E) values lay in the range of 0.8-1.2. Coarse group treat for (n,σ) reactions, especially in resonance range, could result in overestimation. Use of continuous cross section improves consistency of the calculation with the experiment. However, accurate estimate of spectra is necessary when the flux changes largely with energy around the threshold or the resonance peak.

AbstractLow activation material is one of the important factors for constructing high power fusion reactors in future. Unexpected activation, however, may be produced through sequential reactions due to charged particles created by primary neutron reactions. In the present work, the effect of the sequential activation reaction was studied for candidate low activation materials of a fusion demo-reactor. The calculations were conducted by the ACT4 code developed in JAEA for the activation analysis of fusion reactor designs and revised for dealing with the sequential activation reactions. The results say that the real dose rate around vanadium alloy becomes larger after the cooling for 3 years by considering the reaction. Although metal hydrate is regarded as an excellent low activation shield material, the reactions due to recoil protons are influential and the dose rate around vanadium hydrate is several orders of magnitude larger than the value calculated without the sequential process after 2 weeks cooling. In case of liquid breeders, the effect of sequential reactions is popularly observed and it affects the breeder reprocessing and the shield design of circulation loop.

Confinement degradation of energetic ions due to Alfvén eigenmodes (AEs) has been investigated with negative ion based neutral beam injection at ~370?keV into JT-60U weak shear plasmas. AEs with a rapid frequency sweeping and then saturation as the minimum value of the safety factor decreases have been observed. This frequency behaviour can be explained by the reversed-shear induced AE (RSAE) and the transition from RSAEs to the toroidicity-induced AEs (TAEs). The associated change in the charge exchange neutral particle flux suggests energetic ion transport due to these AEs. The total neutron emission reduction rate in the presence of these AEs is evaluated by calculation using the orbit following Monte-Carlo code taking into account the change in bulk plasmas. The evaluation indicates confinement of energetic ions is degraded due to these AEs. In particular, it is found that the confinement degradation of energetic ions is maximum during the transition from RSAEs to TAEs and the maximum reduction rate (?Sn/Sn)MAXis estimated to be ~45%.

This paper presents the significant progress made in the research and development (R&D) of key technologies on the water-cooled solid breeder blanket for the ITER test blanket modules in JAERI. Development of module fabrication technology, bonding technology of armours, measurement of thermo-mechanical properties of pebble beds, neutronics studies on a blanket module mockup and tritium release behaviour from a Li2TiO3pebble bed under neutron-pulsed operation conditions are summarized.

A possibility of applying a compact radiation dosimetry system to burning plasma machines, such as detecting high energy neutrons and gamma-rays with a wide dynamic range at elevated temperatures, has been studied, utilizing radiation resistant optical fibres and radioluminescence (radiation-induced luminescence) materials. Appropriate radioluminescence materials were found for dosimetry of each radiation field, namely, gamma-rays and neutrons. Especially, a high-energy neutron detection system utilizing optical fibres and radioluminescence materials will have several advantages, such as being compact and robust, and can be a strong candidate for diagnostics of fusion neutrons in a burning plasma machine.

Due to the high neutron yield and the large plasma size many ITER plasma parameters such as fusion power, power density, ion temperature, fast ion energy and their spatial distributions in the plasma core can be measured well by various neutron diagnostics. Neutron diagnostic systems under consideration and development for ITER include radial and vertical neutron cameras (RNC and VNC), internal and external neutron flux monitors (NFMs), neutron activation systems and neutron spectrometers. The two-dimensional neutron source strength and spectral measurements can be provided by the combined RNC and VNC. The NFMs need to meet the ITER requirement of time-resolved measurements of the neutron source strength and can provide the signals necessary for real-time control of the ITER fusion power. Compact and high throughput neutron spectrometers are under development. A concept for the absolute calibration of neutron diagnostic systems is proposed. The development, testing in existing experiments and the engineering integration of all neutron diagnostic systems into ITER are in progress and the main results are presented.

To investigate energetic ion transport induced by bursting modes in the frequency range of Alfvén eigenmodes, which is called abrupt large-amplitude events (ALEs) driven by negative-ion-based neutral beam (N-NB) injection, neutron emission profile measurement and charge exchange (CX) neutral particle (flux) measurement using a natural diamond detector have been performed simultaneously in JT-60U. It is found from the CX neutral particle (flux) measurement that energetic neutral particles in a limited energy range (100–370 keV) are enhanced due to ALEs, and the neutron radial profile is flattened. The change in the energetic ion density profile inferred from these measurements indicates that ALEs expel energetic ions from the core region of the plasma and induce both redistribution and loss of energetic ions. It has been shown that the energy range of transported energetic ions is consistent with a resonance condition between energetic ions and ALEs, and the energetic ion transport results from the resonant interaction between energetic ions and ALEs. Further, a fraction of the energetic ion loss has been quantitatively estimated to be ∼4%.

AbstractLarge amount of radioactive erosion and corrosion products are produced in the IFMIF lithium loop in addition to the deuteron-lithium reaction remnant 7Be. An analysis was conducted to estimate the radioactive corrosion products with a design code ACT-4 developed in JAERI, the activation cross sections based on the FENDL library and the IEAF-2001 library, the latest version of nuclear activation data in the intermediate energy range up to 150 MeV. The result says the concentration of the corrosion in lithium is not very large compared with that of 7Be. However, the behavior of the nuclides such as accumulation and detachment on material has not been clarified yet. When the dose rate around the lithium loop was estimated under the condition of 100% plate-out, the value was beyond the acceptable level for the hands-on maintenance near the loop soon after the operation stop. It means that a very efficient cold trap is required so that the 90% activity in the lithium loop is removed.

AbstractRadiation induced change in electrical conductivity of proton conductive ceramics (Yb-doped SrCeO3) have been investigated under 14 MeV fast neutrons in air at temperatures of 293 and 373 K. It was found that the electrical conductivity under neutron irradiation at 293 and 373 K gradually decreased with increased neutron fluence reaching a constant for neutron fluences above 2.0 × 1018and 1.0 × 1017n/m2, respectively. The decrease of the electrical conductivity may be associated with annihilation of sub-bands due to Ce4+to Ce3+conversion.

Fusion product measurements planned for ITER are reviewed from the viewpoint of alpha particle-related physics studies. Recent advances in fusion plasma physics have extended the desirable measurement requirements to the megahertz region for neutron emission rate, better resolution of neutron profiles for the study of internal transport barriers (ITBs), etc. Employing threshold counters and/or scintillation detectors confers megahertz capability on neutron emission rate measurement. The changes in the neutron/alpha particle birth profile due to the formation of ITB and its deviation from uniformity on the magnetic flux surface can be measured by addition of eight viewing chords in an equatorial port plug and seven viewing chords from the divertor to the original radial neutron camera. On the other hand, it is still difficult to measure the distributions of confined and escaping alpha particles. Several proposals to resolve these difficulties are currently under investigation.

A new approach was proposed to significantly improve the D-T neutron monitoring system, which is based on the activation of flowing water via 160(n,p)16N reaction. The basic idea of this approach is to utilize the Cherenkov light, produced by energetic β-particles from 16N in water near the neutron source, and then transmit the light by the optical fiber to the remote light detector. To support this idea, several experimental phases were scheduled. In the present paper, the first phase, measurements of Cherenkov light using a remotely located detector are described. According to the study, the water Cherenkov detector is very efficient for measurements of the 16N activity, due to: high counting efficiency: absence of the scintillation detector; and simplicity of the method.

The neutron shielding design has been carried out for the JT-60 superconducting modification using the boron-doped resin. For the boron doped resin with 0.8 and 2 wt % boron, the neutron transmission experiment with 2.45 MeV neutron source has been performed. The shielding performance of the boron-doped resin for the fast neutron flux does not depend on the boron density in the range of 0.8-2 wt% boron. On the other hand, for the thermal neutron flux the shielding performance of 2 wt% boron is superior to that of 0.8 wt% boron. Most of the reaction rates by DOT3.5 and MCNP calculations agree with the experiment results within 20 %.

In order to investigate applicability of the boron-doped low activation concrete to the DT nuclear fusion reactor, DT neutron irradiation tests were performed together with the standard sample using the FNS facility at JAERI. Radioactivities induced in the specimens were measured during 1 h - 100 d cooling time after 12 h irradiation. From radioactivities detected in the specimens, the effective dose rate was calculated. Dose rates are reduced drastically in the boron-doped low activation concrete compared with those in a standard sample except in the case of a short period of cooling 7 - 10 d after a short period of irradiation less than 20 d. It is concluded that the boron-doped low activation concrete used in the present study is highly useful as a shielding material.

In high power proton accelerator facilities, concrete shield can be highly activated, which makes maintenance work of accelerators quite difficult. So, a low-activationized concrete is planned to be partially adopted as a concrete shield at the accelerator facilities of Japan Proton Accelerator Research Complex (J-PARC) aiming at reducing y-ray exposure dose during maintenance period. The low-activationized concrete is the one using limestone as an aggregate. A new quantity, 24Na-equivalent, was introduced as a criterion to assure effectiveness of the low-activationized concrete. In order to verify its effectiveness, test samples of both the low-activationized concrete and the ordinary concrete were irradiated using FNS at JAERI. The measurements were analyzed by using a shielding design calculation code system being used for J-PARC, showing that the measurements and the calculations of induced activity are in good agreement within a factor of two. Furthermore, by using the same code system, y-ray exposure dose was calculated for modeled configuration of J-PARC to find out that y-ray exposure dose due to the low-activationized concrete was about 10 times lower than that due to the ordinary concrete in a period of less than a few days after operation.

In order to evaluate the decay gamma ray dose rate in the DT nuclear fusion reactor, we developed the Monte Carlo decay gamma ray transport calculation system. By connecting the Monte Carlo calculation code with the activation one, we successfully developed the calculation system. The decay gamma ray dose rates after shutdown calculated by the developed system agree well with the experimental results performed by FNS at JAERI within the experimental error of 10%. We also successfully developed the variance reduction method for the decay gamma ray generating source. It is confirmed that the calculation time can be drastically reduced by applying the developed method. The present calculation system will be useful for the evaluation of the decay gamma ray dose rate in the DT nuclear fusion reactor.

Radiation effects in components and materials will be one of the most serious technological issues in nuclear fusion systems realizing burning-plasmas. Especially, diagnostic components, which should play a crucial role in controlling plasmas and understanding the physics of burning-plasmas, will be exposed to high-flux neutrons and gamma rays. Dynamic radiation effects will affect the performance of components substantially from the beginning of exposure to radiation environments, and accumulated radiation effects will gradually degrade their functioning abilities in the course of their service. High-power-density fission reactors will be the only realistic tools to simulate the radiation environments expected to occur in burning-plasma fusion machines such as the International Thermonuclear Experimental Reactor (ITER), at present. Some key diagnostic components, namely magnetic coils, bolometers, and optical fibres, were irradiation-tested in a fission reactor, to evaluate their performances in heavy radiation environments. Results indicate that ITER-relevant radiation-resistant diagnostic components could be developed in time, although there are still some technological problems to be overcome.

In order to verify the accuracy of the tritium production rate (TPR), neutron irradiation experiments have been performed with a mockup relevant to the fusion DEMO blanket consisting of F82H blocks, Li₂TiO₃ blocks with a ⁶Li enrichment of 40&percent; and 95&percent;, and beryllium blocks. Sample pellets of Li₂TiO₃ were irradiated and the TPR was measured by a liquid scintillation counter. The TPR was also calculated using the Monte Carlo code MCNP-4B with the nuclear data library JENDL-3.2 and ENDF-B/VI. The results agreed with experimental values within the statistical error (10&percent;) of the experiment. Accordingly, it was clarified that the TPR could be evaluated within 10&percent; uncertainty by the calculation code and the nuclear data. In order to estimate the induced activity caused by sequential reactions in cooling water pipes in the DEMO blanket, neutron irradiation experiments have been performed using test specimens simulating the pipes. Sample metals of Fe, W, Ti, Pb, Cu, V and reduced activation ferritic steel F82H were irradiated as typical fusion materials. The effective cross-sections needed to calculate the formation of the radioactive nuclei (⁵⁶Co, ¹⁸⁴Re, ⁴⁸V, ²⁰⁶Bi, ⁶⁵Zn and ⁵¹Cr) due to sequential reactions were measured. From the experimental results, it was found that the effective cross-sections increased remarkably while coming closer to polyethylene board, which was a substitute for water. As a result of this present study, it has become clear that the sequential reaction rates are important factors in the accurate evaluation of induced activity in fusion reactor design.

The diagnostic system of JT-60U (JT-60upgrade) is composed of about 50 individual diagnostic devices. Recently, the detailed radial profile measurements of plasma parameters have been improved, so that the internal structure of plasmas could be explored. The understanding of plasma confinement has been enhanced by density and temperature fluctuation measurements using a mm-wave reflectometer and electron cyclotron emission measurements, respectively. In addition, real-time control experiments of electron density, neutron yield, radiated power, and electron temperature gradient have been carried out successfully by corresponding diagnostic devices. These measurements and the real-time control contribute to improving plasma performance. Diagnostic devices for next generation fusion devices such as a CO2laser interferometer/polarimeter and a CO2laser collective Thomson scattering system have been developed.

The significance of real-time feedback control is emphasized in this paper as an indispensable method to improve and sustain the improved plasma characteristics in JT-60U high fusion performance discharges as well as to operate the fusion reactor under the optimal divertor conditions with respect to the heat load and exhaust pumping. In accordance, substantial improvement in the equivalent fusion amplification gain of over unity has been reproducibly achieved at the JT-60U tokamak in the reversed shear mode of operation with the robust feedback controls, where the value of target density was deliberately optimized for the reliable internal transport barrier formation, and the magneto-hydrodynamic stability control was performed with the stored energy feedback. The feedback control techniques also demonstrated the effectiveness to produce quasi-steady-state high-performance plasmas. In addition, three major parameters associated with the fusion reactor instrumentations, namely the neutron production rate, operating density, and divertor radiation power, were simultaneously feedback controlled in the ELMy H-mode plasmas. Here, the matrix response function was evaluated to identify the limitations involved with the linear combination of independent controls. Other advanced feedback schemes, such as the feedback suppression of the neoclassical tearing mode required to sustain high plasma pressure in a steady-state, are also described. Finally, the controversial issues for the future intelligent plasma control necessary for the advanced steady-stated tokamak reactor are addressed.

Energetic particle experiments in JT-60U are summarized, mainly covering ripple loss and Alfvén eigenmodes (AE modes). Significant loss was observed for 85 keV neutral beam injected (NBI) ions and fusion-produced tritons as toroidal field ripple at the plasma surface increased, especially in a reversed shear plasma. Measurement of hot spots on the first wall due to ripple loss confirmed agreement with code predictions, validating the modeling incorporated in an orbit-following Monte Carlo code. A variety of AE modes were destabilized in ion cyclotron range of frequencies (ICRF) minority heating and negative-ion-based NBI (N-NBI) heating. Most of the observed modes are gap modes identified to be toroidicity-induced, ellipticity-induced, and triangularity-induced AE modes. An interesting finding is pulsating modes accompanying frequency sweep, which were destabilized by N-NBI and sometimes induced a beam ion loss of up to 25%. Also presented are energetic particle issues in auxiliary heating with ICRF and N-NBI.

An overview of the results of the irradiation tests on diagnostic components under the ITER technology R&D tasks and the solutions for the present diagnostic design are given in the light of these results. A comprehensive irradiation database of diagnostic components has been accumulated and permits conclusions to be drawn on the application of these components in ITER. Under the ITER technology R&D tasks, not only has work been shared among four home teams, but also several bilateral collaborations and round-robin experiments have been performed to enhance the R&D activities.

Abstract: The creep behaviour under various combinations of superimposed tensile and hydrostatic loading are quantitatively investigated using nonlinear-viscoelastic cellulose nitrate heated at 65 C. The creep strain and the creep strain-rate are seriously affected by the effect of hydrostatic pressure. The trends of behaviour under superimposed tensile and hydrostatic loading cannot be predicted by the concepts which apply to uniaxial loading. The stress—strain relation of the creep behaviour under superimposed loading is deduced from the invariant theory using an hypothesis of creep potential. The creep data obtained on the cellulose nitrate at 65 C under superimposed loading, as well as uniaxial loading, are found to fit to the deduced relation well.

The creep behaviour in unloading process under various combinations of superimposed tensile and hydrostatic loading are quantitatively investigated using non-linear-viscoelastic cellulose nitrate heated at 65° C. The creep strain and the creep strain-rate in the unloading process are quite influenced by the effect of hydrostatic pressure, but are not so influenced as those in the loading process mentioned in a previous paper. The deformation properties in the unloading process are also discussed with experiments for proportional loading (namely, uniform rate of stress increases or decreases with time). The stress-strain relation in the unloading process of the creep behaviour under superimposed loading is deduced by using the invariant theory. The deduced relation gives good agreement with the actual observations under the superimposed loading.

The cyclic deformations under various repeated stresses are quantitatively investigated using non-linear viscoelastic cellulose nitrate heated to 60° C. The non-elastic strain or creep-plastic strain is remarkably influenced by the repeated stress and the stress rate. The cyclic deformations corresponding to the repeated stress less than a certain stress level attain the saturated state called the “shake down” after some cycles. The stress-strain relations of the non-linear viscoelastic media in the loading and unloading processes are deduced from the invariant theory using an hypothesis of creep potential. The non-linear viscoelastic observations obtained on the cellulose nitrate at 60° C under cyclic loadings are found to fit the deduced relations for the loading and unloading processes independent of the repeated stress and the stress rate.

The effect of up-down asymmetric toroidal field ripple on fast ion loss was investigated experimentally in JT-60U deuterium discharges. The experiment was carried out for neutral beam (NB) injected fast ions and tritons from the d(d,p)t reaction. The loss of the NB injected fast ions was estimated from the decay of 2.5 MeV neutrons following a short pulse D⁰ beam injection of 30 ms, and the triton loss was investigated from the decay of 14 MeV neutrons following 25 MW neutral beam injection (NBI) with a duration of 2 s. It was found that up-down asymmetric ripple did not enhance the NB injected ion loss compared with the ion loss in up-down symmetric ripple. The effect of the ion Del B drift direction on the beam ion and triton losses was studied in up-down asymmetric ripple. No significant difference was observed in the loss for energetic ions between upward and downward Del B drift discharges. The loss fraction of NB injected ions predicted by an orbit following Monte Carlo code agrees with the experimental fraction

The behaviour of polymers is qualitatively known to be remarkably influenced by the hydrostatic pressure on the general plastic deformation, unlike most metals. However, as polymers behave differently in simple tension and compression, they may be influenced by the effect of the third invariant of deviatoric stress tensor as well as hydrostatic pressure. In this paper, a comparison of the effects of the hydrostatic pressure and the third invariant of deviatoric stress tensor on the non-linear viscoelastic deformation of cellulose nitrate are discussed quantitatively, following experiments of torsion of tubular specimens and simple tension of uniaxial specimens. As the result, the effect of the third invariant of deviatoric stress tensor on the non-linear viscoelastic deformation in cellulose nitrate was found to be much smaller than that of the hydrostatic pressure.

As an R&D task of the ITER engineering design activities (EDA), we carried out the irradiation tests on the basic materials of transmission components such as ceramics, windows, fiber optics and mirrors, and in-vessel diagnostics sensors such as magnetic probes and bolometers. Ceramics will be used as general insulating materials. Here we investigated the radiation induced conductivity (RIC) of ceramics for 14 MeV neutrons. Optical elements are the most sensitive to radiation damages among the transmission components. Radiation induce transmission loss of window materials and fiber optics have been measured in the Japan material testing reactor (JMTR). Off line irradiation tests were carried out for molybdenum corner cube reflector (CCR) and gold coated mirrors in JMTR also. Fourteen MeV-neutron-induce luminescence of window material was evaluated in the fusion neutronics source (FNS). Bolometers should be installed inside the vacuum vessel to measure the radiation losses in the infra red to soft X-ray range. We demonstrated the performance of the JT 60 type bolometer under 60Co gamma-rays.

We study symmetrization of hyperbolic first order systems. To be precise, generalizing non-degenerate double characteristics, we define non degenerate characteristics of any order. Then, assuming that the reference characteristic is non degenerate, we prove that the system is smoothly symmetrizable near the characteristic. Applying this result, we also show that non degenerate characteristics can not be removed by hyperbolic perturbations.Copyright 1995, 1999 Academic Press, Inc.

A programmable real-time high-definition television (HDTV) signal processor (HD-VSP) has been developed. For conventional TV signals, a previously reported video signal processor (VSP) has introduced flexible software control capability based on subregional processing. In order to expand such flexibility for real-time HDTV signal processing, the HD-VSP employs eight VSP clusters and programmable time-expansion/compression units. An input HDTV signal is converted to eight time-expanded subregional signals to reduce their sampling rate to that of conventional TV signals. The converted signals are then processed by the eight clusters in the same manner as the VSP. Therefore, programs developed for conventional TV signals can be applied to HDTV with little modification. Processed signals obtained from the eight clusters are time-compressed and multiplexed to reconstruct an output HDTV signal. This HD-VSP has 16 component processors per cluster and is capable of 2.5 giga-operations/s. Several coder programs, including a discrete cosine transform coder and an intraframe differential pulse code modulation (PCM) coder, are developed to evaluate HDTV coding efficiency.<>