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Alain T. Drooz, MD, Curtis A. Lewis, MD, Timothy E. Allen, MD, Steven J. Citron, MD, Patricia E. Cole, PhD, MD, Neil J. Freeman, MD, James W. Husted, MD, Patrick C. Malloy, MD, Louis G. Martin, MD, A. Van Moore, MD, Calvin D. Neithamer, MD, Anne C. Roberts, MD, David Sacks, MD, Orestes Sanchez, MD, Anthony C. Venbrux, MD, Curtis W. Bakal, MD, MPH, for the Society of Interventional Radiology Standards of Practice Committee

The AWE HELEN laser is being used to measure high-pressure Hugoniot data by the impedance match method. Indirect drive is used to generate pressures of up to 10 Mbar in the aluminum reference material. We are aiming to measure shock velocities in our targets to ± 1 %, leading to errors in pressure and particle velocity of the order of ±2%. This requires improvements in target fabrication and characterization, streak camera calibration and data analysis, coupled with investigations into shock planarity and attenuation. Our latest results have accuracies of 2–4% in shock velocity but have identified work that should allow us to achieve our intended level of accuracy. Experiments have been done with copper and chlorinated plastic; our results are compared with theory, and, for copper, with U.S. and Russian gas-gun, explosively or nuclear-driven experiments.

Hollow cylindrical fusion targets of 200–300 μm diam and 500–600 μm length, were fabricated and fitted at one end with a metallic ablator plate. The cylinders were then filled with a solution of polyfunctional acrylate monomer, which was subsequently polymerized to a gel using ultraviolet initiated polymerization. Either one or two aluminum spheres of diameter between 10 and 30 μm were placed in the gel at defined locations, before the gel was precipitated to give, on drying by critical point dryer, a foam of the required density (about 100 mg cm−3). The final targets had the sphere or spheres embedded in the foam at specified locations. Several techniques for placing the spheres were examined and the relative merits of the techniques are discussed.

Nephropathy is an established untoward event associated with intravascular administration of conventional high-osmolality contrast media (HOM). It has not been shown previously that lower-osmolality contrast media (LOM) are less nephrotoxic in a clinical setting. We evaluate the ability to replace HOM with LOM (in lower-extremity angiography) to reduce the incidence of nephropathy. We use multiple definitions for contrast-induced nephropathy (six different magnitudes of rise of serum levels of creatinine or blood urea nitrogen in various periods). The incidences of nephrotoxic effects with LOM vs HOM in patients with presumed risk factors, including preexisting renal insufficiency and diabetes, are evaluated also. When all patients are considered, the incidence of contrast-induced nephropathy for LOM vs HOM (defined as an increase in serum creatinine level greater than 0.3 mg/dl and greater than 20% on day 1, 2, or 3 and on day 5, 6, or 7, is 7% vs 26% (p = .001). When only patients with preangiography azotemia are considered, the incidence of contrast-induced nephropathy for LOM vs HOM is 10% vs 41% (p = .017); for diabetic patients, regardless of preangiography creatinine level, the incidence is 10% vs 31% (p = .012). Although contrast-induced nephropathy may develop even in a patient with no risk factors who receives LOM, LOM is associated with a decreased incidence of this condition, to various degrees, depending on the presence of risk factors.

The performance of subnanosecond‐resolution, Picoframe I and II electron‐optical framing cameras are described for the conditions of UV and soft x‐ray illumination. Experimental data are presented to show that an x‐ray sensitive Picoframe I camera can produce doublet frames having exposure times of ∼250 ps FWHM, interframe times of ∼1.5 ns with a limiting dynamic spatial resolution of 5 lp/mm. The dual‐aperture, Picoframe II camera variant was evaluated with UV and x‐ray illumination and frame periods of ∼120 ps FWHM and interframe times of 400 ps were obtained in both cases. The limiting dynamic spatial resolution was 8 l;p/mm for the UV‐sensitive Picoframe II camera but this was somewhat lower at 4.5 lp/mm for the x‐ray sensitive counterpart.

Curtis W. Bakal, MD, MPH, Chairman, David Sacks, MD, Dana R. Burke, MD, John F. Cardella, MD, Paramjit S. Chopra, MD, Steven L. Dawson, MD, Alain T. Drooz, MD, Neil Freeman, MD, Steven G. Meranze, MD, A. Van Moore, Jr, MD, Aubrey M. Palestrant, MD, Anne C. Roberts, MD, James B. Spies, MD, Eric J. Stein, MD, Richard Towbin, MD, for the Society of Interventional Radiology Standards of Practice Committee

The hydroxymethylglutaryl-coenzyme A reductase inhibitors (HMG-CoAs) are one of the most significant causes of medication induced rhabdomyolysis. The development of rhabdomyolysis is increased when the HMG-CoAs are used concurrently with certain other medications, specifically gemfibrozil and macrolide antibiotics. In this report, we describe a patient with rhabdomyolysis from the combined use of lovastatin, gemfibrozil, and clarithromycin and review the relevant literature.

The AWE HELEN laser is being used to obtain high pressure Hugoniot data by the impedance match method. A hohlraum is used to drive shock pressures of up to 10Mbar in the aluminium reference material. Shock velocities are obtained by observing the visible light emitted on break-out from the surface of the target using optical streak cameras. Planar, wedged and stepped foils have been used to investigate shock planarity, attenuation and velocity. Significant progress has been made in both target fabrication techniques and characterisation. This, coupled to improvements in diagnostic calibration and data analysis, leads us to conclude that an accuracy of 1–2% in shock velocity should be achievable. Preliminary experiments at slightly worse accuracy will be described. Pressures in the region of 2–10Mb are attained in the aluminium standard; these are stepped up into copper or down into plastic. The Hugoniot data derived from the aluminium/copper experiments are compared to those available from US and Russian nuclear driven shots.

The construction and operation of a new titration electrode for measuring C02 are described. Typical results are presented including calibration plots and a comparison of results from the new sensor with those from an infrared analyser. Good agreement is found. Results using the sensor to measure CO2 levels in a glasshouse and in the ambient atmosphere of the laboratory are presented.

Numerous ectopic hormones and markers have been described in small cell carcinoma of the lung as well as in extrapulmonary small cell carcinomas. The authors report a case of a patient with metastatic small cell carcinoma of unknown primary who had very high prostatic acid phosphatase (PAP) and prostatic specific antigen (PSA) levels. Results of multiple prostate examinations, as well as blind biopsies, were normal. His course was significantly longer than that of the usual patient with extensive small cell carcinoma. At autopsy the prostate showed only mild benign prostatic hypertrophy. There are no previous reports in the literature of abnormal prostate markers in small cell carcinomas. Physicians should be aware of the increasing complexity and the unusual biologic markers associated with neuroendocrine carcinomas. In some of these cases, the tumors ability to produce an ectopic product may portend an improved prognosis.

Contrast-induced nephropathy is a potentially serious untoward reaction to radiologic contrast media. The incidence of this nephropathy and the predisposing conditions are not well established, possibly because of methodologic differences between studies. We evaluated the incidence of contrast-induced nephropathy after femoral arteriography in 394 patients by using multiple definitions (different increases in serum creatinine or blood urea nitrogen levels at various times). When an increase in the level of serum creatinine of greater than 0.3 mg/dl and greater than 20% on day 1, 2, or 3 and on day 5, 6, or 7 was used to define the disorder, the incidence in our group of patients was 10% for nonazotemic patients vs 30% for azotemic patients (p less than .001); 2% for nondiabetic, nonazotemic patients vs 16% for diabetic, nonazotemic patients (p = .003); and 38% for patients who were both diabetic and azotemic vs 16% for diabetic, nonazotemic patients (p = .022). Baseline renal insufficiency and diabetes mellitus (especially when insulin dependent) were significant predisposing factors. The effects of dehydration and increased volume of contrast medium on the incidence of contrast-induced nephropathy were not clear; the age and sex of the patient were not important risk factors. The incidence of contrast-induced nephropathy depends on the definition used. Although contrast-induced nephropathy may develop in any patient, diabetes, renal insufficiency, and, possibly, dehydration and dose of contrast medium are risk factors.

Electron-optical framing cameras having X-ray/XUV photosensitivities and which can provide a sequence of framed images in the subnanosecond regime are of major relevance and importance to the quantitative monitoring of the kinetics of laser-produced plasmas. Our Picoframe family of framing cameras which has been developed comprise specially designed image tubes that permit the recording of single or multiple frames in the picosecond domain. For instance, an experimental UV-sensitive Picoframe I camera system has been demonstrated to have temporal and spatial resolution of 100 ps, 8 Ip/mm in single frame format and 250 ps, 8 Ip/mm in a double-frame format having an interframe period between 1.5 ns and 2ns.In this presentation we will describe a double-aperture Picoframe II version of this camera and details will be given in respect of the performance of a demountable, UV-sensitive system. Particular emphasis will be devoted to its operation in a four-frame image format where the generation and implementation of appropriate deflection voltage profiles are especially significant. Experimental data will be presented to show that four discrete frames can be recorded with a frame period of 230 ps, interframe time of ~1 ns and a dynamic spatial resolution (referred to the photocathode) of 7 Ip/mm. This spatial resolution was retained over the entire area of the 6 mm x 6 mm image geometry at the photocathode. Such a UV-sensitive camera can be readily adapted for operation in the soft X-ray spectral region, as previously reported for the Picoframe I counterpart, and some of the projected performance characteristics will be discussed.1. INTRODUCTIONWith the development of ultra-high power, short pulse lasers significant interest has been shown in their potential use to initiate fusion reactions in microballoon type deuterium-tritium filled targets. In order for the reaction to be efficient it is essential that the target be illuminated evenly on all sides in order to provide uniform compression and hence maintain confinement time. It is therefore important to study the two-dimensional evolution of X-ray self-emission of laser-produced plasmas with

The shock pressures generated in the interaction of lasers and light ion beams with thin foils are compared using a one-dimensional hydrodynamic computer code. Using the next generation of proton beam machines at powers of approximately 100 TW, pressure of 25 Mb may be attainable. Similar pressures can be generated with the 1 TW Nd-glass lasers that are currently operating. Much higher pressures should be obtained using lasers at high intensities but the large numbers of high-energy electrons produced in the interaction preheat the target foil making interpretation of experiments difficult. By converting the laser system to the third harmonic (0.35 mu m) it should be possible to achieve pressures in excess of 50 Mb in a preheat-free environment.

The dynamic range of streak cameras with P855 and Photochron II tubes at various pulse duration and wavelengths is reported. Values recorded with 8 ps pulses were about 400 for Photochron II tubes and about 150 for P855 tubes. A spread in electron transit times between grid and phosphor caused by space charge is suggested as a possible mechanism for temporal broadening in the Photochron II.

The paper reviews a number of X-ray streak cameras developed at AWRE. These cameras are used to provide temporal and one-dimensional spatial or spectral information on X-rays emitted from laser produced plasmas. Two of these cameras have been designed to be combined with other diagnostic instrumentation; one with a Wolter X-ray microscope (×22 magnification) and the other with a Bragg diffraction crystal spectrometer. This latter instrument provides a few eV spectral resolution and ∼15 ps temporal resolution; a typical experimental application at the AWRE HELEN laser facility will be described. The paper describes the circuitry of the bipolar avalanche transistor ramp generator used to drive the streak plates of the cameras. Improvements to this include: (a) increasing the fastest streak rate to ∼10 ps mm−1 by a distributed capacitance network across each of the bipolar stacks of transistors, and (b) reducing the trigger jitter to approximately ±10 ps by the use of a new mix of transistors in the stack and a Raytheon RS 3500 avalanche transistor. Additional improvements have now been added. These include a ‘half-scan’ user facility to aid initial camera timing and direct switching to select the sweep rate of the camera.

By assuming that incident ions are scattered in a single wide-angle collision and that the energy loss in the solid is due only to interaction with electrons, an expression for the number of ions back-scattered from a surface is derived. Measurements have been made of the energy distribution of protons and deuterons back-scattered from titanium and niobium. Good agreement is obtained between the measured and calculated energy distributions both in general shape and in the absolute values of the number of particles back-scattered from titanium. In the case of niobium there is evidence that multiple scattering is taking place.

Sputtering coefficients of niobium for bombardment by Nb, H, D, and He ions in the 10‐ to 80‐keV range have been measured and compared with theory. The light‐ion measurements were obtained by sputtering through a thin film (600 A) of niobium deposited on a zirconium substrate. Penetration of the film was observed by the appearance of substrate ions in the mass spectrum of sputtered ions from the target.

A solution is given for the problem of the torsion of an elastic cylinder welded to an elastic half space. The problem was formulated so as to involve coupling between dual-integral equations and Dini series. These equations were reduced to a single integral equation. Numerical results are given and functions found that approximate the stress distribution.

The torsion of an infinite elastic circular cylindrical fibre, containing a penny-shaped crack, and embedded in an infinite elastic matrix, is considered. Using integral transform techniques the problem is reduced to the solution of a Fredholm integral equation of the second kind, provided the fibre remains unbroken. A solution to the Fredholm integral equation is obtained by iteration, and by direct numerical methods. Curves of the bond stress for various ratios of the crack radius to the radius of the fibre, and for different values of the elastic constants, are also given. Stress singularities of a fractional order are noted when the fibre is broken.

The long term performance of a 30.48 cm radius 90° sector double collecting mass spectrometer using a novel automatic capacitor integrating detector for high precision isotopic analysis of carbon dioxide is described. The incorporation of a new design of changeover valve in the dual inlet system and other aspects of the design of the mass spectrometer have resulted in the reduction of all the instrumental corrections applicable to measured isotopic differences between sample and standard gases to a negligible level. Isotopic differences in the ratio of ratios can be determined routinely with a reproducibility (expressed as the 1σ standard deviation about the mean value obtained by replicate analysis) of better than ±0.002%. The efficiency of the ion source is about 5×10 −4 ions molecule −1 . The leak correction has averaged 0.004±0.016‰ for the 46/(44+45) ratio and −0.025±0.008‰ for the 45/44 ratio. The sums of all the other instrumental corrections (background, valve mixing, and abundance sensitivity) are 1.00038 for δ46/(44+45) values and 1.00078 for δ45/44 values. These values compare favourably with published sums of correction factors which average about 1.03. The capacitor integrating detector has the advantages that the ion beam intensities are objectively averaged, it runs the mass spectrometer automatically once set up, and provides a digital output.

A prolate spheroidal field β-spectrometer is described in which the source and detector are located on the same side of the focal ring slit. The trajectories reach distances of up to 38 cm from the axis and the ring slit has a radius of 33 cm. The relation between the resolution and transmission has been measured for four source diameters. Using a scintillation detector of 1.85 cm diameter and 1 cm length, a resolution W of 1.28% at a transmission T of 1% of 4π has been found for a source of 1 cm diameter. For a 1 mm source the measured value range from W=0.4% at T=0.8% to W=1.52% at T=5.2%.

This paper deals with the axially symmetric torsion of a semi-infinite cylinder embedded into an elastic half space, where the cylinder is allowed to protrude by a finite amount. The problem is formulated to include the case of the protruding portion of the cylinder when it is a different material and partially bonded to the embedded portion. With the use of integral transforms and Dini series, the problem is reduced to the determination of the solution of an integral equation. Stress singularities of a fractional order are noted and computed at the juncture, when all members are perfectly bonded. A numerical solution of the integral equation is obtained for the case of a homogeneous cylinder. The bond stress on the cylinder—half space interface and the torque-twist (and consequently, strain energy) for the entire system are computed for different values of the elastic constants.

The beta, gamma and internal conversion electron spectra of 144Ce have been studied with a magnetic spectrometer, scintillation counter and coincidence techniques. The internal conversion coefficients of the 80keV and 133keV γ-rays were measured. Four partial beta spectra were observed and new evidence has been found for a level at 166keV in the 144Pr nucleus. No evidence was found for the 95keV and 145keV γ-rays in the decay.

A solution is given for the problem of axially symmetric torsion of a finite elastic cylindrical rod partially bonded to an elastic half space. The problem is formulated in a manner that involves coupling between dual Dini series and dual integral equations. Auxiliary functions are introduced and the problem is reduced to the solution of a Fredholm integral equation of the second kind. Approximate closed-form results are obtained when the radius of the bonded region is less than one-half the radius of the cylinder. Fractional order singularities in the stress are noted and calculated for the case when the crack vanishes.

The depth distribution of deuterium in metal targets has been measured by sputtering the metal surface with a 60 keV Bi beam and monitoring the partial pressure of deuterium released into the target chamber with an MS 10 mass spectrometer. No significant differences were found for the distributions from D+, D2+, and D3+ bombardments with 20 and 30 keV energy per incident atom.The sputtering coefficient, measured by the loss in weight of a target, was used to calculate ranges for the energy interval 5–80 keV. These are compared with previous experimental and theoretical values.

The torsion of two finite, coaxial, circular cylinders, of dissimilar materials, in contact, is considered. The surface of contact is assumed to consist of two parts: an exterior region of slip and an interior region of adhesion. Assuming that slip has progressed a sufficient amount, an analytical expression is given relating the angle of twist with the constant shear stress (assumed) in the slip region, necessary to eliminate a singularity in stress. The special case of an external crack, corresponding to zero shear stress in the slip region, is also discussed.

The shapes, intensities and end-points of the three strong components of the 144Pr beta spectrum have been measured with a prolate spheroidal field spectrometer and coincidence techniques. A spin of 0- has been assigned to the ground state of 144pr on the basis of these measurements. It is shown that the pure axial vector correction factor for a ΔI = 0 (yes) transition provides a good fit to the ground state spectrum. The spectrum of the β-transition to the 695 kev level in 144Nd has a unique first forbidden shape.

A retardation device situated after the final collector slit of a tandem magnetic mass spectrometer has improved the abundance sensitivity measured on the low mass side of a Cs+ peak from 1 × 106 to 4 × 109. On the high mass side the abundance sensitivity of approximately 109 is not affected significantly by the retardation technique. The abundance sensitivity extrapolated to the uranium mass region is improved from 5 × 105 to 109 on the low mass side and is 108 on the high mass side.

An ion probe facility is described. A single stage magnetic mass spectrometer coupled to an energy selective ion detector has been used to analyze sputtered ions. Energy selective operation is demonstrated for the analysis of a stainless steel sample.

The requirement for a sensitive two-dimensional imaging diagnostic with picosecond time resolution, particularly in the study of laser-produced plasmas, has already been discussed [1]. A temporal sequence of framed images would provide useful supplementary information to that provided by time resolved streak images across a spectral region of interest from visible to x-ray. To fulfil this requirement the Picoframe camera system has been developed. Results pertaining to the operation of a camera having S20 photocathode sensitivity are reviewed and the characteristics of an UV/x-ray sensitive version of the Picoframe system are presented.

Publisher Summary This chapter discusses multiple-frame ultra violet (UV)/X-Ray p Picoframe system icosecond framing camera. A temporal sequence of framed images can provide useful supplementary information to that provided by time-resolved streak images across a spectral region of interest from visible to X-ray. To fulfill this requirement the picoframe camera system has been developed. To ensure adequate light gain in dynamic operation and to limit detrimental spacecharge defocusing effects because of the high photocurrents, a microchannel plate image intensifier (Mullard type XXl330A) is fiber-optically coupled to the output phosphor. Results pertaining to the operation of a camera having S·20 photocathode sensitivity are reviewed and the characteristics of a UV/X-ray sensitive version of the Picoframe system are presented in the chapter. However, it is suspected that photocathode defects accounted for a significant degradation in the image modulation and that improved X-ray photocathode fabrication techniques can lead to enhanced instrumental functions.

Details are given of the vacuum system, magnet, ion source, electrostatic focusing system and electrical supplies of a 100 cm radius, 90° sector, electromagnetic separator which is now under construction at A.W.R.E., Aldermaston. The machine is designed to produce milligramme quantities of stable isotopes and radioactive isotopes up to 1 millicurie strength. An effort is being made to secure a higher vacuum than has been used in the past, with the principal objects of obtaining a higher resolution and enrichment factor.

The construction of a bakable changeover valve for high precision mass spectrometric comparison of the isotopic composition of gases is described. The leakage across the valve seats is about an order of magnitude smaller than the values published for similar valves in use, and the ``mixing correction'' which can be a significant correction to the experimental data is negligible.

IN a controlled thermonuclear plasma it is necessary to minimize the entry into the hot plasma of low energy particles produced by the impact of fast particles on the walls of the container. These particles may be either particles of wall material or reflected incident particles. They can cool the plasma by two processes. The first process is a loss of bremsstrahlung radiation as a result of the interaction of atoms of high atomic charge from wall material with the fast electrons in the plasma. The second process of charge transfer between the atoms of the wall material and the energetic hydrogen ions in the plasma produces neutral hydrogen atoms which are subsequently lost to the walls. A study has been made of the burial of deuterium ions (D+) in stainless steel and titanium since these metals are commonly used in the construction of ultra high vacuum systems. The mechanisms of hydrogen trapping in these two metals differ considerably since a hydride can be formed with titanium but not with the elements in stainless steel.

The branching ratio of thorium C (Bi/sup 212/) was determined from the intensities of the two alpha particle groups. Sources of ThB were electrcdeposited from thoron on a polished brass surface, 1 mm in diameter, and were mounted 1 cm above an aperture of the same diameter in a mica disc covering the crystal. The branching ratio was found to be alpha /( alpha + BETA ) = 0.359 plus or minus 0.002. (J.R.D.)