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The ITER electron cyclotron emission (ECE) diagnostic system has primary roles in providing measurements of the core electron temperature profile and the electron temperature fluctuation associated with the neoclassical tearing modes. The ITER ECE system includes a radial and oblique line-of-sight. Four 43-meter long low-loss transmission lines (TLs) are designed to transmit millimeter wave power in the frequency range of 70–1000 GHz in both X- and O-mode polarization from the port plug to the ECE instrumentation room in the diagnostic building. The measurement instrumentation includes two Fourier transform spectrometer (FTS) systems and two radiometer systems. The Indian Domestic Agency (IN-DA) and United States Domestic Agency share the responsibility. The IN-DA scope excluding instrumentation and control has passed its preliminary design review and is progressing towards the final design review (FDR). In parallel, the diagnostic integration in different areas is ongoing. Several captive components for the TLs have passed FDR and will be manufactured for installation in the tokamak building soon. A peer review meeting has been held on the prototype hot calibration source, and its integration and new thermal analysis in the diagnostic shield module are continuing. A prototype TL is being tested. A prototype polarizing Martin-Puplett type FTS, operating in the frequency range 70–1000 GHz, features an in-vacuo fast scanning mechanism and a cryo-cooled dual-channel THz detector system. Its performance has been assessed in detail against ITER requirements.

This paper describes the preliminary engineering investigation of the optical labyrinth and the first and second mirror mounts of the ITER core LIDAR diagnostics. The optical labyrinth is in a very sensitive location being close and open to the plasma. Therefore, it has been examined carefully to be able to provide different solutions satisfying the needs of the diagnostics. The present conceptual design considered the covering of the light path, the integration of the labyrinth into the port plug, as well as the shape, color, and material of the labyrinth inner surface. It was absolutely necessary, since the undesirable phenomena of scattered light and sputtered particles reaching the mirroring surface must be handled. Nevertheless, cooling/baking has also been considered, and appropriate solutions have been presented. Regarding the mirror mounts, concepts have been created. It has been identified that the mirrors must be conditioned at a certain temperature; therefore, cooling/baking options were developed. The cooling/baking and, particularly, the neutron absorption functions were detected to be essential for the extension tubes. The development basically focused on the different installation methods of the neutron-shielding plates, which also allow the tubes to be kept in the required temperature range. The result of the development was that a water-steel mixture varied through the length of the extension tubes could provide the maximum neutron shielding. This solution could satisfy the very strict six-orders-of-magnitude neutron absorption required to maintain the postoperation safety. The conceptual engineering design has been supported by the preliminary thermal analysis of the mirror extension tubes.

The paper generally outlines a design of new multichannel optical diagnostics for the COMPASS (COMPact ASSembly) tokamak. The final design of a port plug for a multispectral diagnostic tool is introduced and its evolution taking into consideration spatial and other technical restrictions is reviewed. A similar solution of both focusing optics and optical signal diversion will be used for a new Thomson scattering (TS) system, which is specified in the second part of the article. Main parameters of the TS system, such as laser energy and regions of observation, were determined with respect to both electron temperature and density profiles and required ultrahigh spatial resolution at the plasma edge.

Quasi-stationary H-mode plasmas have been produced on MAST and submitted to the ITPA H-mode confinement database. The MAST data are expanding the database by a factor of 2.2 in inverse aspect ratio e = a/R and by a factor of 2.5 in thermal toroidal β. The MAST energy confinement times broadly agree with the IPB98(y, 2) scaling law. Merger with the published international database shows that the energy confinement time in MAST supports an e dependence consistent with the subset of conventional shaped cross-section tokamaks when represented in engineering parameters. In dimensionless parameters, MAST indicates that the collisionality dependence might be stronger than in the IPB98(y, 2) scaling. MAST data link e and β scalings and, as a result, the proposed β independence would imply smaller e exponent. L-mode confinement exceeds the value given by the current L-mode scaling, suggesting a stronger e dependence than predicted. In H-mode, the working particle transport in the core is dominated by the Ware pinch and the neutral beam source.

The development of reliable H-modes on MAST, together with advances in heating power and a range of high spatial resolution diagnostics, has provided a platform to enable MAST to address some of the most important issues of tokamak stability. In particular the high beta potential of the spherical tokamak is highlighted with stable operation at beta(N) similar to 5-6, beta(T) similar to 16% and beta(p) up to similar to2. Magnetic diagnostic evaluation of the global beta parameters is independently confirmed by kinetic profile data. Calculations indicate that the beta(N) values are in the vicinity of no-wall stability limits. Studies of neoclassical tearing modes (NTMs) have been extended to explore their effects and develop avoidance strategies. Experiments have demonstrated that sawteeth play a strong role in triggering NTMs-by avoiding large sawteeth a much higher beta(N) value has been reached. The significance of NTMs is confirmed, with large islands observed using the 300 point Thomson scattering diagnostic, and locking of large n = 1 modes frequently leading to disruptions, which become more rapid at low q(95). The role of error fields has been explored. H-mode plasmas are also limited by edge localized modes (ELMs), with confinement degraded as the ELM frequency rises. However, in contrast to the conventional tokamak, the ELMs in high performing regimes on MAST (H-IPB98Y2 similar to 1) appear to be type III in nature. Modelling using the ELITE code, which incorporates finite n corrections, identifies instability to peeling modes, consistent with a type III interpretation. It also shows considerable scope to raise pressure gradients before ballooning type modes (perhaps associated with type I ELMs) occur. The calculations show that narrow pedestals can support much stronger pressure gradients than might be expected from simple n = infinity ballooning calculations. Finally sawteeth are shown to degrade confinement by similar to10-15% in particular cases examined. They are observed not to remove the q = 1 surface in the cases where snakes are present-various physics models of the sawteeth are now being explored. Thus research on MAST is not only demonstrating stable operation at high performance levels and developing methods to control instabilities; it is also providing detailed tests of the stability physics and models applicable to conventional tokamaks, such as ITER.

The augmented bearings-only target motion analysis (TMA) problem arises when the bearing measurements of the classical bearings-only TMA problem are augmented with received signal-to-noise ratio (SNR) measurements. A combined acoustic propagation and sensor (CAPS) performance prediction model specifying the conditional density of the SNR measurements is assumed given; however, mismatch may exist between the CAPS model and the real world. We present a novel "missing data" formulation of the augmented bearings-only TMA problem using an empirical maximum a posteriori (EMAP) method for target parameter estimation, and show that it provides a natural and straightforward technique for mitigating CAPS model mismatch. The EMAP approach leads to an iteratively reweighted, linear least-squares algorithm for solving both the augmented bearings-only TMA problem and the classical (nonaugmented) bearings-only TMA problem. Examples are provided.

The letter reports the first use of laser ablation of trace impurities into a reversed field pinch (RFP) similar to that used in tokamaks, but selecting different impurity elements appropriate to the confinement times of present RFPs. The ionization rates from helium-like carbon and boron are sufficiently slow to allow measurements of particle confinement times from line intensity decay rates of the near UV transitions. A zero-dimensional treatment, incorporating impurity ionization and confinement, is used to interpret the temporal behaviour of the line intensity. The results obtained yield typical particle confinement times of about 1 ms.

The first part of this paper presents stress intensity factor solutions for coalescing coplanar semi-elliptical cracks subjected to pure bending. Crack shapes of “beachmarked” test pieces were modelled using a finite element method and stress intensity factors were obtained using an elastic strain energy method and a displacement extrapolation method. The second part presents the results of an experimental investigation of the fatigue propagation of coplanar semi-elliptical cracks. Fatigue tests were carried out for stress ratios of 0.2, 0.5, and 0.7, and for initial crack separations of 4 mm, 8 mm, and 16 mm. In part III various models are employed for the prediction of fatigue crack growth of coalescing coplanar cracks. The implications for fatigue life assessment are discussed.

A set of time-skewed analog-to-digital converters (ADCs) in combination with a complex finite-impulse response (FIR) filter has been utilized to directly sample and demodulate RF signals. This architecture is referred to as a complex analog-to-digital converter (CADC) B.W. Tietjen. The clock signals driving the ADCs are staggered in time such that the system achieves an effective sampling rate commensurate with the carrier frequency of interest, while each ADC need only run at a rate greater than the immediate bandwidth of interest. The output of each ADC is fed into the complex bandpass filter, which suppresses the input signal's image frequency to produce I and Q data. The data rate out of the filter is equal to the ADC clock rate; thus the RF band of interest is aliased down to baseband or a low IF band. Hardware implementations of the CADC architecture have been achieved for both UHF and S-Band. The measured values of signal-to-noise ratio (SNR) and image rejection for both prototypes closely match expected results. Furthermore, by using the CADC to down-convert the RF band of interest to a low IF band, a second digital filter can be used to easily suppress any harmonics introduced by the ADC hardware. This provides superior spurious-free dynamic range (SFDR) and increased SNR performance. This technique is demonstrated using the UHF prototype. An automatic filter-tuning algorithm is also implemented to adaptively balance the amplitude and phase of the ADC channels composing the CADC. This technique allows the CADC filter to operate as expected despite hardware imperfections.

Traditional bearings-only target motion analysis (TMA) statistical models assume a priori that measurements are independent when conditioned on the target. This paper presents a novel track-before-detect "empirical" maximum a posteriori (EMAP) approach in which measurements are assumed independent prior to the detection decision. The EMAP estimators proposed here are joint detection/estimation methods whose intended use is target tracking. A limiting case of the EMAP formulation is shown to be equivalent to the traditional maximum likelihood (ML) formulation. Triangulation and constant velocity target examples are presented. The EMAP algorithm is an iteratively re-weighted linear least squares algorithm for these problems, and has significantly lower computational complexity than the standard ML estimator.

Several improvements to the MAST plant and diagnostics have facilitated new studies advancing the physics basis for ITER and DEMO, as well as for future spherical tokamaks (STs). Using the increased heating capabilities P NBI ⩽ 3.8 MW H-mode at I p = 1.2 MA was accessed showing that the energy confinement on MAST scales more weakly with I p and more strongly with B t than in the ITER IPB98(y, 2) scaling. Measurements of the fuel retention of shallow pellets extrapolate to an ITER particle throughput of 70% of its original designed total throughput capacity. The anomalous momentum diffusion, χϕ, is linked to the ion diffusion, χi, with a Prandtl number close to P ϕ ≈ χϕ/χi ≈ 1, although χi approaches neoclassical values. New high spatial resolution measurements of the edge radial electric field, E r , show that the position of steepest gradients in electron pressure and E r (i.e. shearing rate) are coincident, but their magnitudes are not linked. The T e pedestal width on MAST scales with rather than ρpol. The edge localized mode (ELM) frequency for type-IV ELMs, new in MAST, was almost doubled using n = 2 resonant magnetic perturbations from a set of four external coils (n = 1, 2). A new internal 12 coil set (n ⩽ 3) has been commissioned. The filaments in the inter-ELM and L-mode phase are different from ELM filaments, and the characteristics in L-mode agree well with turbulence calculations. A variety of fast particle driven instabilities were studied from 10 kHz saturated fishbone like activity up to 3.8 MHz compressional Alfvén eigenmodes. Fast particle instabilities also affect the off-axis NBI current drive, leading to fast ion diffusion of the order of 0.5 m2 s−1 and a reduction in the driven current fraction from 40% to 30%. EBW current drive start-up is demonstrated for the first time in a ST generating plasma currents up to 55 kA. Many of these studies contributed to the physics basis of a planned upgrade to MAST.

The extraction of iron(III) from aqueous nitrate solutions by the water insoluble carboxylic acids n-octanoic, n-nonanoic, n-decanoic, 2-ethylhexanoic, 3,5,5-trimethylhexanoic and phenylacetic acids is discussed in terms of the structure of the acid, the diluent and the nature of the extracted complex. The extraction can be adequately described by the equation Fe 3+ + 1 2 (3 + x − n) (HR) 2 + H 2 O ⇋ Fe (OH) n R 3 −n.x HR + 3 H + x.

Acute toxicity tests were carried out on two alkyl polyethoxylate surfactants (CH3·[CH2]11–12·[OCH2·CH2]6·OH, or C13E6 and CH3·[CH2] 13–14·[OCH2·CH2]7·OH, or C14E7) and on two detergent formulations containing 33% of either of the alkyl polyethoxylate (AEx) surfactants. The acute oral toxicity was low in rats, dogs and monkeys. Emesis was produced in the dogs and monkeys and probably accounted for the generally lower activities of the test compounds in these species compared with the rat. Pharmacological responses (convulsions and/or depression) were seen in ip studies in mice, rats and monkeys; however, the doses required for these effects were generally in the lethal range. When the surfactants were given orally, pharmacological effects were not seen unless lethal doses were given. The acute dermal toxicity of these materials was low in rabbits and guinea-pigs but moderate skin irritation was produced under occluded patches after 24 hr (concentrations up to 10%). Patch tests on human skin produced only minor irritation after 4hr at concentrations of 25 or 100%. Young guinea-pigs immersed to chest level for 4 hr in 25% AEx developed only slight irritation. AEx surfactants and formulations were severely irritating to the rabbit eye but had a much less severe and more transient effect on the monkey eye. Rat studies indicated a low inhalation toxicity. In general, these results suggest that C13E6 and C14E7 would not involve significant risk to man under conditions of predicted use and potential misuse.

A novel leg-positioning and holding mechanism has been developed to facilitate knee surgery. The normal thigh tourniquet is used as the point of attachment of the mechanism. The knee may be placed in any of the positions desired for knee surgery by means of a single control lever. To facilitate alignment during arthroplasty a pointer has been incorporated to indicate the midline of the limb. The leg positioner has proved useful during knee arthroplasty, high tibial osteotomy, arthroscopic procedures, and ligament reconstruction. Its use has reduced fatigue, freed the assistant for other tasks, and held the limb more firmly than was possible hitherto.

We have purified to homogeneity and analyzed the amino acid composition of a small (Mr 14,000), basic (pi 9.0) protein from human plasma. This has been named acylation stimulating protein (ASP) because it markedly stimulates triacylglycerol synthesis in human adipocytes. As well, it stimulates triacylglycerol synthesis in human skin fibroblasts cultured from normal individuals. Characteristic saturation curves for the cell metabolic responses to ASP were observed in both cell types with higher stimulation of oleate incorporation into triacylglycerol being observed in adipocytes. The stimulation of triacylglycerol synthesis was much greater with ASP than with insulin. Neither fatty acid binding protein nor albumin was able to mimic the ASP effect.

The extraction of Fe(III) from aqueous solutions by phenylacetic acid in chloroform solution provides a simple, rapid, and accurate method for the determination of low amounts of iron. Concentrations less than 1 μg/ml can be easily determined particularly if advantage is taken of the amplification procedure afforded by the solvent extraction technique by using a large aqueous to organic phase ratio. A maximum concentration of iron(III) of about 18 μg/ml in the aqueous phase (aqueous to organic phase ratio of 2.5:1) can be determined; however, above this concentration deviations from Beer's Law occur for the absorbance of the organic phase. The method is very selective, particularly in the presence of copper, provided care is taken to adjust the aqueous pH to a value of 2.8. n -Decanoic acid could also be used in the method in place of phenylacetic acid and would have some advantage in selectivity, particularly in cases where very large amounts of Ag(I) and Pb(II) were present.

The background philosophy and technical requirements of a low cost development system with universality are discussed. The evolution of such a system which gives universal support for most microprocessors is explained together with a discussion of the technical development of the product.

1 The administration of 0.5 mg glyceryl trinitrate by chewing and keeping under the tongue increased heart rate in normal subjects in the supine and erect posture. 2 There was no significant difference between the responses in the same subject on repeated administration of glyceryl trinitrate on different days but there was a significant difference between the responses in different subjects. 3 The oral administration of practolol and propranolol reduced the responses to glyceryl trinitrate. The two drugs progressively reduced the increase in heart rate produced by glyceryl trinitrate; there was no significant difference between their effects. Propranolol produced a significantly greater reduction than practolol in the maximum heart rate that was produced by glyceryl trinitrate. 4 The administration of practolol (300 mg) twice daily by mouth to patients after an acute episode of ischaemic heart disease significantly reduced the increases in heart rate produced by standing and by glyceryl trinitrate in comparison to the responses in similar patients receiving a placebo.

Thirteen pregnancies of obligate heterozygotes of cystic fibrosis have been prospectively monitored utilizing quantitative and qualitative measurements of methylumbelliferylguanidinobenzoate (MUGB) reactive proteases in amniotic fluid. In each case the diagnosis was accurately ascertained in midtrimester and confirmed after delivery. The measurement of MUGB reactivity in midtrimester amniotic fluid by three different procedures, quantitative analysis, polyacrylamide isoelectric focusing, and column filtration appears to provide a practical and reliable approach for the intrauterine detection of cystic fibrosis.

This paper reviews five cases of partial arterial division illustrating various stages in the evolution of false traumatic aneurysms.

The control of triglyceride synthesis within the adipocyte is not fully understood. Insulin is considered to be the most potent stimulant of triglyceride synthesis. In this paper, we report on the effect of a small (14000 Da), basic (p I 9.0) protein isolated from human serum. This protein has been called acylation stimulating protein (ASP). It is a potent stimulant of triglyceride synthesis in adipocytes from both normal weight and morbidly obese subjects. Its stimulatory effect on adipocytes is both rapid, occurring between 15–30 min after the start of incubation, and prolonged, lasting for up to 3 hr. Compared to insulin, it is sixfold more potent in its effect on triglyceride synthesis. As well as acting on isolated cells, ASP also has a fourfold stimulatory effect on triglceride synthesis in human adipose microsomes at a concentration of 25 μg/ml. This study indicates that ASP is a potent stimulant of triglyceride synthesis and therefore may play a role in the pathogenesis of morbid obesity.