Optimal Exposure Conditions Research Articles

Photographic Properties of Single-crystalline AgBr Films

AbstractThe photographic properties of single0crystalline AgBr films were studied and compared with those of polycrystalline films. The single-crystalline films were found to have about a two times loiver sensitivity than polycrystalline films. The minimum energy to record an image was estimated to be about 10-5 J/cm2. The strong low intensity failure and solarization observed in vapour-deposited AgBr film are discussed in terms of the rehalogenation of the latent image centres. At optimum exposure and processing conditions the single-crystalline films resolve sub-micrometer details with line widths of 0.3 µm. The very good reproducibility of their preparation, as well as the already achieved limit of the resolving power, as given by the wavelength of light exposure, make single-crystalline AgBr films attractive for practical application in some special cases. For single-crystalline films, epitaxially grown in (001) orientation on LiF substrates, the epitaxial relationship has been identified.

16. デジタル撮影装置 (インテグリス V3000) における最適撮影条件の自動設定について(第 10 回放射線機器技術発表会予稿)

16. デジタル撮影装置 (インテグリス V3000) における最適撮影条件の自動設定について(第 10 回放射線機器技術発表会予稿)

Response of various animal species to experimental infection with different strains of Staphylococcus aureus.

An experimental infection program was conducted in rabbits, pigs, and baboons with toxic shock syndrome (TSS)-associated and non-TSS-associated strains of Staphylococcus aureus to produce an animal model for TSS. TSS-associated strains of S. aureus--whether positive or negative for TSS toxin 1 (TSST-1)--could not be distinguished from non-TSS-associated strains of S. aureus by means of the rabbit whiffle-ball infection model; therefore, limited pilot infection studies were conducted in pigs and baboons. Experimental conditions were optimized in both the pig and the baboon studies to maximize the chance of producing TSS. Pigs infected with TSS-associated S. aureus strain CDC-11 developed some of the clinical signs observed in TSS (fever, hypotension, diarrhea, and vomiting). However, no changes were detected in clinical chemistry or hematology. Baboons infected with S. aureus strain CDC-11 showed only minimal signs of illness, i.e., lethargy, decreased food intake, and loose stools. TSS was not produced in pigs or baboons, even under optimal exposure conditions.

Study of half-micron photolithography by means of contrast enhanced lithography process

A simple, but efficient, analysis method has been developed to evaluate material properties, process conditions, and effectiveness of contrast enhanced lithography (CEL). The method, realized as a result of the systematic calculation and concept, is based on the evaluation of the energy transmittance of the contrast enhancing material (CEM). In practical applications of the new method to the design and evaluation of both CEM characteristics and half‐micron contrast enhanced photolithography, the method has been proved to be useful in the precise design as it shows good agreement with experimental results. The study has brought us pieces of important information on such design as the optimum exposure conditions, the ideal CEM characteristics, etc. Based on the information, we have developed a new CEM, water soluble photopolymer (WSP) for i and g lines. Through the simulation, it has been confirmed that the ultimate resolution can be improved by 20% to 30%.

A small coleoid cephalopod with soft parts from the lower Devonian discovered using radiography

During the past 50 years, X-ray examinations have greatly increased our knowledge of fossils. Modern radiographic methods, X-ray tubes with fine focal spots, high-resolution films and optimal exposure conditions have revealed details of the anatomy and general biology of ancient life as well as species and representatives of major groups hitherto unknown in the Lower Devonian1–5. Most of this material came from the Hunsriick slate, where most fossils are converted to pyrite, FeS2, giving a good contrast in the radiographs. Additional image processing may reveal even more details. While screening large quantities of black slate pieces, I have discovered a small teuthid coleoid showing soft parts (Fig. 1) which is the best-preserved specimen I have found during 20 years of investigation. This Eoteuthtis elfriedae n.sp. is very similar to the living Alloteuthis africana of the Loliginidae, and is one of many unusual fossils yielded by this slate3–5, only a few of which have been published. This specimen of E. elfridea shows that Alloteuthis-like animals have not changed much over the past 400 Myr, and means that previous concepts of the appearance of such forms must be revised.

Optimization of exposure conditions for medical ultrasound.

Optimum exposure conditions are values of acoustic exposure parameters (e.g., intensity, pressure amplitude, time) which yield maximum net medical benefit in a therapeutic or diagnostic procedure. It is generally agreed that if the exposure values are too low, the procedures are ineffective, while if they are too high, harm will result. However, little quantitative information exists on what specific values the parameters should have to give greatest net benefit in various applications. The determination of optimum exposure conditions is an important goal, but the process is likely to be a long one, requiring efforts by many individuals and groups. In this review several approaches to the problem are discussed, and difficulties are pointed out.

乳房撮影系における写真特性と透過X線スペクトルについて

The combination of molybdenium anode X-ray tube (with a beryllium window and 0.03mm molybdenium filter) and a single high resolution intensifying screen (rare earth phosphors) with a green-sensitive single emulsion film is regarded as a very useful and optimum system for mammography. In order to find the optimum exposure condition in this system that we investigated the transmission properties of the mammographic cassette, the intensifying screen and the specimen of breast. We examined four cassettes by the contrast (0.1/0.5mm aluminium), the visibility of small particles (Mg_2 SiO_4,150〜600μm diameter) by five observers and dose measurements using mammographic phantom, Kodak Min-R screen and Fuji RX-M film. We measured the transmission photon spectra by using pure germanium detector through tumor and normal glandular tissue of breast cancer (3.5kg weight, 6.5cm, thickness and 1.0cm tumor diameter) after surgery. We examined the relationship between the contrast and the transmission photon spectra of macro-specimen of breast cancer (fixation in 10% folmalin solution). Then we selected the phantom materials for mammography which have the same property as the specimen of cancer in the transmission spectra. From these results, the low tube voltage (25kV)technique gives high contrast and good visiblity of small particles in this system. Also in the system, the smaller X-ray absorption of cassette (or package) gives higher contrast, better visiblity and lower dose. For the phantom materials, ABS resin has almost same transmission property as the measured normal glandular tissue and Lucite is almost same as the measured tumor and glandular from the point of transmission spectra.

けい光増感オートラジオグラフィによるα放射性じんあいの粒子径測定

An autoradiographic technique in estimating size of air-borne plutonium was studied by using ZnS(Ag) intensifier screen and Polaroid film. Effects of screen thickness, a weight percent of binder added and a particle size of ZnS(Ag) powder on a spot size of autoradiograph were examined. A calibration curve between alfa activity and spot size of autoradiograph produced under optimum exposure condition is presented. All procedures of the autoradiography can be performed without darkroom by the use of an improved Polaroid camera which has a double light-tight attachment.

Some application problems and solutions in Xeromammography

Experience in the xeromammographic procedure has shown some paradoxical findings in demonstrating breast lesions. A skin halo of 1 -2 mm. is not the only criterion of an adequately exposed xeromammogram. Studies were carried out to assess the optimum exposure conditions. By use of a water-scattering phantom, and some clinical studies, image spacial frequency and image recording latitutde are to be found to be dose dependent. Xeromammographic exposures ideally should be tailored to suit the type of pathology under investigation.

Electron scattering and line profiles in negative electron resists

Starting with a depth-dose theory of electron energy dissipation in negative electron resists and a quasimonoenergetic Gaussian scattering theory, we derive theoretical expressions for single-line profiles using the exposure parameters of the Bell Laboratories electron-beam exposure system (EBES). These profiles are calculated by convoluting the Gaussian scattering distribution with the experimentally determined relationship between resist thickness remaining after development and input electron dose. Calculated profiles for the negative electron resist P(GMA-co-EA) agree well with experimental results for the range of feature sizes exposed on EBES. Since features on EBES are built up by multiple passes, the theory is extended to line profiles separated by the address structure of EBES. The calculated resist profiles are in reasonably good agreement with experimental results. The observed profile heights are somewhat greater than predicted by theory since the developed gel is not perfectly rigid and gel interaction takes place between neighboring profiles. The results show the importance of good gel rigidity and high contrast for negative electron resists used in high resolution applications. The range of validity of the trends predicted by the quasimonoenergetic theory for increasing film thickness and operating voltage are extended using a Monte Carlo approach which includes the effects of energy loss. The calculated trends have led to the choice of optimum exposure conditions for EBES.

Electron-beam exposure of optical gratings

Because of electron scattering, optimum exposure conditions for optical gratings written with a scanning electron microscope depend on the grating period. Experimentally determined exposure conditions are given for gratings of periods down to 230 nm deposited on both conducting and nonconducting substrates. Optimum exposures are shown to be in good agreement with theoretical predictions, but exposure latitude is less than predictions indicate.

Fundamental aspects of electron beam lithography. II. Low-voltage exposure of negative resists

A study has been made of the use of low-voltage exposure of negative resists for electron lithography. Three resists have been investigatd; an esterified terpolymer, epoxidized polybutadiene, and polyglycidyl methacrylate. The optimum exposure conditions have been determined for each material, and the use of a low accelerating voltage (5 kV) found to be advantageous. The application of this technique for the pattern delineation of silicon dioxide and tungsten is described.

Der Einfluss von sauerstoff auf lichtempfindlichkeit und bildqualität des Photolacks KTFR

The effect of O 2 on KTFR photoresist layers has been studied using the microprojektion technique. For very thin films the requested exposure time in air is approximately 300 times longer than that in N 2. A short heat treatment will increase the light sensitivity nearly to the level observed in N 2. On thick resist films only the top layer becomes insensitive in air. The thickness w of this desensitized layer is, for medium exposure times, virtually only dependent on the illumination B and the partial pressure p 0 of the O 2 in the ambient ( w ∼ √ ( p 0/ B)). To explain these observations it is proposed that during exposure O 2 is trapped in the resist, and that it is resupplied by diffusion from the surface. The quality of the image and the broadening of slit patterns was also investigated. Optimum exposure conditions are given.

Size determination of airborne plutonium particles by autoscintigraphy.

Size measurements of airborne plutonium particles have been made by recording the photographic image produced by scintillations from a zinc sulphide screen kept in contact with the sample. A calibration curve giving the relation between the 239PuO2 particle size and the spot size produced under optimum exposure conditions is presented and the limitations of the method are discussed. A nomogram is also presented from which the activity of a single particle can be converted to its size for particles of plutonium, uranium and some of their compounds. This technique of measuring particle size from the size of the photographic image produced by scintillations has been termed “autoscintigraphy”.

Experiments on technology and performance of Lippmann-Bragg phase holograms

For many technical applications, Lippmann-Bragg phase holograms are interesting because of their wavelength selectivity and the theoretical possibility of obtaining reconstruction efficiencies near 100%. We performed experiments on such holograms using photographic emulsions. With commercially available plates having 7μm emulsion thickness we obtained reproducible efficiencies above 10% and very low light scattering, optimum exposure conditions to achieve this are described. The dependence of the reflection factor on wavelength and emulsion thickness is in agreement with theory. With our results an efficiency of 50~ can be predicted for the same emulsion but with a thickness of 20~m. This indicates that despite their high spatial frequency requirements, Lippmann-Bragg holograms can be superior to the more conventional transmission holograms.