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Sample records for dental x-ray film

  1. Quality control procedure for dental x-ray film processing

    International Nuclear Information System (INIS)

    Tingey, D.R.C.

    1983-08-01

    Methods of obtaining the optimum processing from dental films are discussed. A method of quality control of developing conditions for dental x-ray films has been developed. It is relatively easy to maintain and is sufficiently accurate for practical purposes

  2. Information about radiographic films rejects of dental x-rays

    International Nuclear Information System (INIS)

    Cezimbra, M.R.; Bernarsiuk, M.E.; Bauer V, E.

    1996-01-01

    The purpose of this research was to qualify and quantify the number of dental x-ray films rejected in a Porto Alegre clinic. As we analyzed the captured data, it was concluded that, our of 1066 peri-apical films, we had a total percentage of 4.5% in relation to the total of the exams made. This 4.5% consists of the following rejects: placement, patient movement, technical errors, diaphragm, too much clarity in the result, double exposure, prolongation, shortness, darkened for not have been shot, superposed film. Because of that, the rejection, due to the bad placement of the film, is the one with the larger percentage value, i.e., 1.22% of the 4.5%. With the knowledge of the types of rejects and their causes, it was possible to correct some sources of systematic errors minimizing the repetition of the exams, saving costs, time and diminishing the ionizing radiation exposure for the patient, odontologist and his technical staff, which will be proved. (authors). 4 refs., 1 tab

  3. Lead foil in dental X-ray film: Backscattering rejection or image intensifier?

    International Nuclear Information System (INIS)

    Hönnicke, M.G.; Delben, G.J.; Godoi, W.C.; Swinka-Filho, V.

    2014-01-01

    Dental X-ray films are still largely used due to sterilization issues, simplicity and, mainly, economic reasons. These films almost always are double coated (double emulsion) and have a lead foil in contact with the film for X-ray backscattering rejection. Herein we explore the use of the lead foil as an image intensifier. In these studies, spatial resolution was investigated when images were acquired on the dental X-ray films with and without the lead foil. Also, the lead foil was subjected to atomic analysis (fluorescent measurements) and structure analysis (X-ray diffraction). We determined that the use of the lead foil reduces the exposure time, however, does not affect the spatial resolution on the acquired images. This suggests that the fluorescent radiation spread is smaller than the grain sizes of the dental X-ray films

  4. Lead foil in dental X-ray film: Backscattering rejection or image intensifier?

    Science.gov (United States)

    Hönnicke, M. G.; Delben, G. J.; Godoi, W. C.; Swinka-Filho, V.

    2014-11-01

    Dental X-ray films are still largely used due to sterilization issues, simplicity and, mainly, economic reasons. These films almost always are double coated (double emulsion) and have a lead foil in contact with the film for X-ray backscattering rejection. Herein we explore the use of the lead foil as an image intensifier. In these studies, spatial resolution was investigated when images were acquired on the dental X-ray films with and without the lead foil. Also, the lead foil was subjected to atomic analysis (fluorescent measurements) and structure analysis (X-ray diffraction). We determined that the use of the lead foil reduces the exposure time, however, does not affect the spatial resolution on the acquired images. This suggests that the fluorescent radiation spread is smaller than the grain sizes of the dental X-ray films.

  5. Quality control for dental X-rays equipment and film developers

    International Nuclear Information System (INIS)

    Pomares C, Martin

    1998-01-01

    Quality control in five dental X-ray equipments, film and film developers was done. It was for evaluating the radiologic practices in the odontologic services too. This work was made based on international standards, the results will be used for future works in quality assurance in dental radiology

  6. A comparison of Kodak Ultraspeed and Ektaspeed plus dental X-ray films for the detection of dental caries.

    Science.gov (United States)

    Wong, A; Monsour, P A; Moule, A J; Basford, K E

    2002-03-01

    Using the fastest dental X-ray film available is an easy way of reducing exposure to ionizing radiation. However, the diagnostic ability of fast films for the detection of proximal surface caries must be demonstrated before these films will become universally accepted. Extracted premolar and molar teeth were arranged to simulate a bitewing examination and radiographed using Ultraspeed and Ektaspeed Plus dental X-ray films. Three different exposure times were used for each film type. Six general dentists were used to determine the presence and depth of the decay in the proximal surfaces of the teeth radiographed. The actual extent of the decay in the teeth was determined by sectioning the teeth and examining them under a microscope. There was no significant difference between the two films for the mean correct diagnosis. However, there was a significant difference between the means for the three exposure times used for Ultraspeed film. The practitioners used were not consistent in their ability to make a correct diagnosis, or for the film for which they got the highest correct diagnosis. Ektaspeed Plus dental X-ray film is just as reliable as Ultraspeed dental X-ray film for the detection of proximal surface decay. The effect of underexposure was significant for Ultraspeed, but not for Ektaspeed Plus. Patient exposure can be reduced significantly with no loss of diagnostic ability by changing from Ultraspeed X-ray film to Ektaspeed Plus X-ray film.

  7. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Weiss, M.E.

    1980-01-01

    Intra-oral dental X-ray apparatus for panoramic dental radiography is described in detail. It comprises an electron gun having an elongated tubular target carrier extending into the patient's mouth. The carrier supports an inclined target for direction of an X-ray pattern towards a film positioned externally of the patient's mouth. Image definition is improved by a focusing anode which focuses the electron beam into a sharp spot (0.05 to 0.10 mm diameter) on the target. The potential on the focusing anode is adjustable to vary the size of the spot. An X-ray transmitting ceramic (oxides of Be, Al and Si) window is positioned adjacent to the front face of the target. The electron beam can be magnetically deflected to change the X-ray beam direction. (author)

  8. Panoramic Dental X-Ray

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a very small dose of ... x-ray , is a two-dimensional (2-D) dental x-ray examination that captures the entire mouth ...

  9. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Weiss, M.E.

    1980-01-01

    Intra-oral dental X-ray apparatus for panoramic radiography is described in detail. It comprises a tubular target carrier supporting at its distal end a target with an inclined forward face. Image definition is improved by positioning in the path of the X-rays a window of X-ray transmitting ceramic material, e.g. 90% oxide of Be, or Al, 7% Si0 2 . The target carrier forms a probe which can be positioned in the patient's mouth. X-rays are directed forwardly and laterally of the target to an X-ray film positioned externally. The probe is provided with a detachable sleeve having V-form arms of X-ray opaque material which serve to depress the tongue out of the radiation path and also shield the roof of the mouth and other regions of the head from the X-ray pattern. A cylindrical lead shield defines the X-ray beam angle. (author)

  10. Study on the characteristics of insight dental x-ray film

    International Nuclear Information System (INIS)

    Song, Young Han; Lee, Wan; Lee, Byung Do

    2003-01-01

    To investigate the characteristics of the newly marketed, Insight dental X-ray film. Kodak Ultraspeed (DF-58), E-speed, Agfa Dentus M2, and Kodak Insight (IP-21) films were radiographed using a Trophy intra-oral radiographic machine. 10 step exposure times were prepared and each step exposure was monitored using a FH 40G (ESM Eberline Instruments) dosimeter for each of the 4 types of intra-oral film. All films were manually processed and the radiographic densities at 6 site of each processed film were measured, and the characteristic curves of each of the 4 types intra-oral films were created utilizing these dosimetric data and radiographic densities, based on ISO 5779. The film contrast, speed, and base plus fog density of Insight film were compared with those of the 3 other films examined in this experiment. E-speed film showed greatest average gradients followed by Insight film. E-speed and Ultraspeed film showed great average gradients at low density levels. Insight film showed the fastest speed followed by E-speed, Dentus M2 and Ultraspeed film. Dentus M2 film showed greatest base plus fog density level followed by Insight film. Kodak Insight film showed fastest film speed with comparable film contrast on characteristic curve.

  11. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Weiss, M.E.

    1980-01-01

    Intra-oral X-ray apparatus which reduces the number of exposures necessary to obtain panoramic dental radiographs is described in detail. It comprises an electron gun, a tubular target carrier projecting from the gun along the beam axis and carrying at its distal end a target surrounded by a shield of X-ray opaque material. This shield extends forward and laterally of the target and has surfaces which define a wedge or cone-shaped radiation pattern delimited vertically by the root tips of the patient's teeth. A film holder is located externally of the patient's mouth. A disposable member can fit on the target carrier to depress the patient's tongue out of the radiation pattern and to further shield the roof of the mouth. The electron beam can be magnetically deflected to change the X-ray beam direction. (author)

  12. X-ray film

    International Nuclear Information System (INIS)

    Arndt, U.W.; Gilmore, D.J.; Wonacott, A.J.

    1977-01-01

    The performance of film as an X-ray detector is discussed and its behaviour is compared with that of a perfect Poissonian detector. The efficiency of microdensitometry as a method of extracting the information recorded on the film is discussed. More emphasis is placed in the precision of microdensitometric measurements than on the more obvious characteristic of film speed. The effects of chemical fog and background on the precision of the measurements is considered and it is concluded that the final limit to precision is set by the chemical fog. (B.D.)

  13. A comparison of Kodak Ultraspeed and Ektaspeed Plus dental X-ray films for use in endodontics.

    Science.gov (United States)

    Moule, A J; Wong, A; Monsour, P A; Basford, K E

    2001-06-01

    The advantage of using a faster film for length determination in endodontic therapy is obvious. However, for such a film to be generally accepted, it must demonstrate comparable diagnostic quality to traditionally used films. The comparative accuracy of canal length determination of Ultraspeed and Ektaspeed Plus dental X-ray films was assessed in maxillary first and second molars; for different canals, for different teeth, for different exposures, and for different examiners (five general dentists and three endodontic specialists). In general, there were no significant differences between films, among examiners, or any interaction between films and exposures. That is, an assessor's ability to estimate lengths was not significantly influenced by the film type or by exposure used. There was a wide divergence in the individual assessor's ability to estimate lengths. Specialists estimated lengths more accurately than general practitioners and estimated lengths more accurately with Ektaspeed Plus film. Length determination in distobuccal and mesiobuccal canals was more accurate than in palatal canals. Most palatal canals were underestimated in length by more than 1mm. The use of file sizes larger in number than size 15 is recommended in these canals. For length determination, Ektaspeed Plus dental X-ray film is as effective as Ultraspeed film. Given the acceptable quality and accuracy of Ektaspeed Plus film, there seems to be no clinical reason to subject patients to greater radiation by using a slower film during endodontic therapy.

  14. Electronic quality control on dental x-rays equipment

    International Nuclear Information System (INIS)

    Pomares C, Martin

    1996-09-01

    A brief description of dental x-ray equipment is done. The non-invasive quality control is treated as than the responsibilities from the dentists to the patient and the equipment. A propose for quality control for dental x-ray equipment, film and developer is include

  15. A comparison of density of Insight and Ektaspeed plus dental x-ray films using automatic and manual processing

    International Nuclear Information System (INIS)

    Yoon, Suk Ja

    2001-01-01

    To compare the film density of Insight dental X-ray film (Eastman Kodak Co., Rochester, NY, USA) with that of Ektaspeed Plus film (Eastman Kodak) under manual and automatic processing conditions. Insight and wedge on the film under the three different exposure times. The exposed films were processed by both manual and automatic ways. The Base plus fog density and the optical density and the optical density made by exposing step wedge were calculated using a digital densitometer (model 07-443, Victoreen Inc, Cleveland, Ohio, USA). The optical densities of the Insight and Ektaspeed film versus thickness of aluminum wedge at the same exposure time were plotted on the graphs. Statistical analyses were applied for comparing the optical densities of the two films. The film density of both Insight films and Ektaspeed Plus films under automatic processing condition was significantly higher over the manual processing. The film density of Insight over Ektaspeed Plus film. To take the full advantage of reducing exposure time, Insight film should be processed automatically

  16. X-ray film calibration

    International Nuclear Information System (INIS)

    Stone, G.F.; Dittmore, C.H.; Henke, B.L.

    1986-01-01

    This paper discusses the use of silver halide x-ray films for imaging and spectroscopy which is limited by the range of intensities that can be recorded and densitometered. Using the manufacturers processing techniques can result in 10 2-3 range in intensity recorded over 0-5 density range. By modifying the chemistry and processing times, ranges of 10 5-6 can be recorded in the same density range. The authors report on x-ray film calibration work and dynamic range improvements. Changes to the processing chemistry and the resulting changes in dynamic range and x-ray sensitivity are discussed

  17. The reliability of dental x-ray film in assessment of MP3 stages of the pubertal growth spurt.

    Science.gov (United States)

    Abdel-Kader, H M

    1998-10-01

    The main object of this clinical study is to provide a simple and practical method to assess the pubertal growth spurt stages of a subject by recording MP3 stages with the dental periapical radiograph and the standard dental x-ray machine.

  18. Use and regulatory control of dental X-ray installations

    International Nuclear Information System (INIS)

    1999-01-01

    In the guide the safety requirements concerning dental X-ray installations and their use, prerequisities for exemption from a safety licence, and regulatory control are presented. The guide applies to conventional dental X-ray installations, by which an image is created on an X-ray film or other image receptor placed inside the mouth, and panorama tomography installations for dentition and the cephalostats associated with these. The guide does not apply to multitechnique tomography installations intended for the special imaging of the skull or jaws

  19. X-ray spot film device

    International Nuclear Information System (INIS)

    1981-01-01

    Improvements are described in an X-ray spot film device which is used in conjunction with an X-ray table to make a selected number of radiographic exposures on a single film and to perform fluoroscopic examinations. To date, the spot film devices consist of two X-ray field defining masks, one of which is moved manually. The present device is more convenient to use and speeds up the procedure. (U.K.)

  20. Routine dental x-ray : a health hazards

    International Nuclear Information System (INIS)

    Parthasarathy, K.S.

    1978-01-01

    In orthopantography (OPG) technique, a single panoramic x-ray replaces a dozen or so conventional x-ray exposures required for a full-mouth examination. OPG, thus, reduces radiation dose to the patients. However, the very simplicity of the OPG technique may lead to its misuse. The dentists are tempted to take too many OPG films and thus exposing the patients unnecessarily to X radiation. Dentists are advised against making dental x-radiography a routine part of examinations. Greater care should be exercised particularly in the case of children while using OPG. (M.G.B.)

  1. Exposure reduction in general dental practice using digital x-ray imaging system for intraoral radiography with additional x-ray beam filter

    International Nuclear Information System (INIS)

    Shibuya, Hitoshi; Mori, Toshimichi; Hayakawa, Yoshihiko; Kuroyanagi, Kinya; Ota, Yoshiko

    1997-01-01

    To measure exposure reduction in general dental practice using digital x-ray imaging systems for intraoral radiography with additional x-ray beam filter. Two digital x-ray imaging systems, Pana Digital (Pana-Heraus Dental) and CDR (Schick Technologies), were applied for intraoral radiography in general dental practice. Due to the high sensitivity to x-rays, additional x-ray beam filters for output reduction were used for examination. An Orex W II (Osada Electric Industry) x-ray generator was operated at 60 kVp, 7 mA. X-ray output (air-kerma; Gy) necessary for obtaining clinically acceptable images was measured at 0 to 20 cm in 5 cm steps from the cone tip using an ionizing chamber type 660 (Nuclear Associates) and compared with those for Ektaspeed Plus film (Eastman Kodak). The Pana Digital system was used with the optional filter supplied by Pana-Heraus Dental which reduced the output to 38%. The exposure necessary to obtain clinically acceptable images was only 40% of that for the film. The CDR system was used with the Dental X-ray Beam Filter Kit (Eastman Kodak) which reduced the x-ray output to 30%. The exposure necessary to obtain clinically acceptable images was only 20% of that for the film. The two digital x-ray imaging systems, Pana Digital and CDR, provided large dose savings (60-80%) compared with Ektaspeed Plus film when applied for intraoral radiography in general dental practice. (author)

  2. X-ray exposures to dental patients

    International Nuclear Information System (INIS)

    McKlveen, J.W.

    1980-01-01

    An elastic mask worn by patients and a skeleton encased in plastic were instrumented with LiF thermoluminescent dosimeters to determine radiation exposures delivered from full-face diagnostic dental X-rays. Measurements were made using various panoramic radiographical and periapical machines. Locations of interest included skin surface, eyes, upper and lower teeth and thyroid. Exposures in the 100 mR range were common and a maximum of over 6000 mR was measured in the teeth region during a full-face examination with a periapical unit. In general, exposures received from periapical equipment were several times those obtained from panoramic devices. (author)

  3. Intraoral radiology in general dental practices. A comparison of digital and film-based X-ray systems with regard to radiation protection and dose reduction

    Energy Technology Data Exchange (ETDEWEB)

    Anissi, H.D. [Ulm Univ. (Germany). Dentistry; Geibel, M.A. [Ulm Univ. (Germany). Dept. of Dentomaxillofacial Surgery

    2014-08-15

    Purpose: The purpose of this study was to gain insight into the distribution and application of digital intraoral radiographic techniques within general dental practices and to compare these with film-based systems in terms of patient dose reduction. Materials and Methods: 1100 questionnaires were handed out to general dental practitioners. Data was analyzed with respect to the type of system by using descriptive statistics and nonparametric tests, i.e. Kruskal-Wallis, Mann-Whitney and chi-square test (SPSS 20). Results: 64% of the questioned dentists still use film-based radiology, 23% utilize storage phosphor plate (SPP) systems and 13% use a charge-coupled device (CCD). A strong correlation between the number of dentists working in a practice and the use of digital dental imaging was observed. Almost 3/4 of the film users work with E- or F-speed film. 45% of them refuse to change to a digital system. The use of lead aprons was popular, while only a minority preferred thyroid shields and rectangular collimators. A fourfold reduction of exposure time from D-speed film to CCD systems was observed. Due to detector size and positioning errors, users of CCD systems take significantly more single-tooth radiographs in total. Considering the number of radiographs per patient, there is only a slight tendency towards more X-rays with CCD systems. Up to image generation, digital systems seem to be as or even more difficult to handle than film-based systems, while their handling was favored after radiographic exposure. Conclusion: Despite a slight increase of radiographs taken with CCD systems, there is a significant dosage reduction. Corresponding to the decrease in exposure time, the patient dose for SPP systems is reduced to one half compared to film. The main issues in CCD technology are positioning errors and the size of the X-ray detectors which are difficult to eliminate. The usage of radiation protection measures still needs to be improved. (orig.)

  4. Intraoral radiology in general dental practices - a comparison of digital and film-based X-ray systems with regard to radiation protection and dose reduction.

    Science.gov (United States)

    Anissi, H D; Geibel, M A

    2014-08-01

    The purpose of this study was to gain insight into the distribution and application of digital intraoral radiographic techniques within general dental practices and to compare these with film-based systems in terms of patient dose reduction. 1100 questionnaires were handed out to general dental practitioners. Data was analyzed with respect to the type of system by using descriptive statistics and nonparametric tests, i.e. Kruskal-Wallis, Mann-Whitney and chi-square test (SPSS 20). 64% of the questioned dentists still use film-based radiology, 23% utilize storage phosphor plate (SPP) systems and 13% use a charge-coupled device (CCD). A strong correlation between the number of dentists working in a practice and the use of digital dental imaging was observed. Almost 3/4 of the film users work with E- or F-speed film. 45% of them refuse to change to a digital system. The use of lead aprons was popular, while only a minority preferred thyroid shields and rectangular collimators. A fourfold reduction of exposure time from D-speed film to CCD systems was observed. Due to detector size and positioning errors, users of CCD systems take significantly more single-tooth radiographs in total. Considering the number of radiographs per patient, there is only a slight tendency towards more X-rays with CCD systems. Up to image generation, digital systems seem to be as or even more difficult to handle than film-based systems, while their handling was favored after radiographic exposure. Despite a slight increase of radiographs taken with CCD systems, there is a significant dosage reduction. Corresponding to the decrease in exposure time, the patient dose for SPP systems is reduced to one half compared to film. The main issues in CCD technology are positioning errors and the size of the X-ray detectors which are difficult to eliminate. The usage of radiation protection measures still needs to be improved. ► Responsible use of digital intraoral radiology results in a significant

  5. Intraoral radiology in general dental practices. A comparison of digital and film-based X-ray systems with regard to radiation protection and dose reduction

    International Nuclear Information System (INIS)

    Anissi, H.D.; Geibel, M.A.

    2014-01-01

    Purpose: The purpose of this study was to gain insight into the distribution and application of digital intraoral radiographic techniques within general dental practices and to compare these with film-based systems in terms of patient dose reduction. Materials and Methods: 1100 questionnaires were handed out to general dental practitioners. Data was analyzed with respect to the type of system by using descriptive statistics and nonparametric tests, i.e. Kruskal-Wallis, Mann-Whitney and chi-square test (SPSS 20). Results: 64% of the questioned dentists still use film-based radiology, 23% utilize storage phosphor plate (SPP) systems and 13% use a charge-coupled device (CCD). A strong correlation between the number of dentists working in a practice and the use of digital dental imaging was observed. Almost 3/4 of the film users work with E- or F-speed film. 45% of them refuse to change to a digital system. The use of lead aprons was popular, while only a minority preferred thyroid shields and rectangular collimators. A fourfold reduction of exposure time from D-speed film to CCD systems was observed. Due to detector size and positioning errors, users of CCD systems take significantly more single-tooth radiographs in total. Considering the number of radiographs per patient, there is only a slight tendency towards more X-rays with CCD systems. Up to image generation, digital systems seem to be as or even more difficult to handle than film-based systems, while their handling was favored after radiographic exposure. Conclusion: Despite a slight increase of radiographs taken with CCD systems, there is a significant dosage reduction. Corresponding to the decrease in exposure time, the patient dose for SPP systems is reduced to one half compared to film. The main issues in CCD technology are positioning errors and the size of the X-ray detectors which are difficult to eliminate. The usage of radiation protection measures still needs to be improved. (orig.)

  6. Dental x-ray image segmentation

    Science.gov (United States)

    Said, Eyad; Fahmy, Gamal F.; Nassar, Diaa; Ammar, Hany

    2004-08-01

    Law enforcement agencies have been exploiting biometric identifiers for decades as key tools in forensic identification. With the evolution in information technology and the huge volume of cases that need to be investigated by forensic specialists, it has become important to automate forensic identification systems. While, ante mortem (AM) identification, that is identification prior to death, is usually possible through comparison of many biometric identifiers, postmortem (PM) identification, that is identification after death, is impossible using behavioral biometrics (e.g. speech, gait). Moreover, under severe circumstances, such as those encountered in mass disasters (e.g. airplane crashers) or if identification is being attempted more than a couple of weeks postmortem, under such circumstances, most physiological biometrics may not be employed for identification, because of the decay of soft tissues of the body to unidentifiable states. Therefore, a postmortem biometric identifier has to resist the early decay that affects body tissues. Because of their survivability and diversity, the best candidates for postmortem biometric identification are the dental features. In this paper we present an over view about an automated dental identification system for Missing and Unidentified Persons. This dental identification system can be used by both law enforcement and security agencies in both forensic and biometric identification. We will also present techniques for dental segmentation of X-ray images. These techniques address the problem of identifying each individual tooth and how the contours of each tooth are extracted.

  7. Accidental over-exposure from dental X-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, B G [National Radiological Protection Board, Harwell (UK)

    1976-07-01

    A description is given of an unusual dental X-ray procedure which resulted in accidental over-exposure both to the dentist and to several of his patients when a short-circuit was present in newly-installed equipment. The short-circuit by-passed the exposure control and energized the tube for certain orientations of the X-ray tube. The dentist left the patients, who wore protective aprons, to initiate the exposure themselves, using the control button. Although the warning lights were on, the dentist was not present in the room during the exposure, and the over-exposures were only detected when the developed X-ray films were found to be completely blackened. A reconstruction of the procedure enabled estimates to be made of the dose equivalents to the dentist's body and to the skin of the head, the eyes and the gonads of the patients. The dentist had overlooked several of basic principles recommended in the Code of Practice for the Protection of Persons against Ionizing Radiations from Medical and Dental Use (1972). It is pointed out that incidents involving failure of dental equipment (usually the timer mechanism) are not infrequent.

  8. Panoramic dental X-ray machine X-motion drive

    International Nuclear Information System (INIS)

    Cushman, R.H.; Flynn, J.J.

    1980-01-01

    A panoramic dental x-ray machine is described which provides continuous and discontinuous radiographic images of the dental arch area of a patient. The systems for moving the chair and the column which carries the x-ray source and camera are specified. (U.K.)

  9. X-ray film spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Trelles, F.; Caputo, M.C. (Buenos Aires Univ. Nacional (Argentina). Lab. de Fisica del Plasma; Ministerio de Defensa, Buenos Aires (Argentina). DIGID)

    1982-02-15

    A multi-pinhole camera using film as a detector is described. Separation of variables in the master-curve sense leads to integral exposure equations which are solved by regularization. A filter-selection method is used to maximize the information content of a given set of measurements. Numerical simulation examples of the unfolding procedure are shown and the inversion error is evaluated. The essential role of absorption edges of filters and detectors for increasing the information content is emphasized and the method is compared with other absorption-edge techniques. A discussion of the present limitations of the method is given.

  10. X-ray beam qualities for dental radiology purposes

    International Nuclear Information System (INIS)

    Santos, Marcus Aurelio P. dos; Fragoso, Maria da Conceicao de F.; Lima, Ricardo de A.; Hazim, Clovis A.

    2009-01-01

    In order to establish characteristics or properties of equipment for diagnostic radiology, e.g. ion chambers and semiconductor detectors, calibration laboratories offer a set of well-defined radiation conditions, called X-ray qualities, which can be used for many Physics studies and medical purposes. The standardization of radiation qualities has been carried out in several fields of study, but little attention has been given to the area of dental radiology, mainly for medical and physical applications using single-phase units with half-wave rectification. For this reason, a single-phase dental unit with adjustable peak voltage and tube current, called 'variable potential X-ray equipment', was developed aiming to define X-ray beam qualities for test and calibrations purposes. X-ray spectra at 50, 60 and 70 kVp were determined by using a CdTe detector and compared with those obtained for ten commercial X-ray dental units. As a result of this study, a set of X-ray qualities for the variable potential X-ray equipment was determined. The X-ray qualities spectra were utilized as reference for determination of a new set of X-ray qualities characterized for a constant potential X-ray equipment. Thus, sets of X-ray qualities were standardized and implemented in two X-ray laboratories: one with the variable potential X-ray equipment and other with constant potential X-ray equipment. These reference X-ray beam qualities should be used for test and calibration purposes involving scientific studies and services. (author)

  11. Dental X-ray diagnostic facility with means to choose the time of exposure

    Energy Technology Data Exchange (ETDEWEB)

    Krause, H; Grassme, U

    1978-02-16

    Equipment for dental X-ray diagnostics with automatic exposure control. In the patient's mouth there is arranged a film carrier containing in a pocket a dental X-ray film. A detector-transmitter assembly touches the pocket. It reacts to the density of the film and wireless transmits a signal to an antenna. This antenna is connected to a receiver shutting off the high voltage of the X-ray tube by means of a circuit if a desired dose value is reached. The detector-transmitter unit is an integrated component. It has got a luminescent layer with a light-sensitive detector or a detector directly sensitive to X-rays.

  12. Thin Films for X-ray Optics

    Science.gov (United States)

    Conley, Raymond

    Focusing x-rays with refraction requires an entire array of lens instead of a single element, each contributing a minute amount of focusing to the system. In contrast to their visible light counterparts, diffractive optics require a certain depth along the optical axis in order to provide sufficient phase shift. Mirrors reflect only at very shallow angles. In order to increase the angle of incidence, contribution from constructive interference within many layers needs to be collected. This requires a multilayer coating. Thin films have become a central ingredient for many x-ray optics due to the ease of which material composition and thickness can be controlled. Chapter 1 starts with a short introduction and survey of the field of x-ray optics. This begins with an explanation of reflective multilayers. Focusing optics are presented next, including mirrors, zone plates, refractive lenses, and multilayer Laue lens (MLL). The strengths and weaknesses of each "species" of optic are briefly discussed, alongside fabrication issues and the ultimate performance for each. Practical considerations on the use of thin-films for x-ray optics fabrication span a wide array of topics including material systems selection and instrumentation design. Sputter deposition is utilized exclusively for the work included herein because this method of thin-film deposition allows a wide array of deposition parameters to be controlled. This chapter also includes a short description of two deposition systems I have designed. Chapter 2 covers a small sampling of some of my work on reflective multilayers, and outlines two of the deposition systems I have designed and built at the Advanced Photon Source. A three-stripe double multilayer monochromator is presented as a case study in order to detail specifications, fabrication, and performance of this prolific breed of x-ray optics. The APS Rotary Deposition System was the first deposition system in the world designed specifically for multilayer

  13. Automatic film loader for X-ray spot film device

    International Nuclear Information System (INIS)

    1975-01-01

    A light tight tunnel extends over the top of a diagnostic X-ray table. A film cassette is mounted for reciprocating in the tunnel between an X-ray exposure position and a position in which the cassette is unloaded or loaded with film automatically. Unexposed films are dispensed one at a time into the cassette from a feed magazine at one end of the tunnel. After exposure, the film is ejected from the cassette into a receiving magazine at the same end of the tunnel. (Auth.)

  14. Digital Dental X-ray Database for Caries Screening

    Science.gov (United States)

    Rad, Abdolvahab Ehsani; Rahim, Mohd Shafry Mohd; Rehman, Amjad; Saba, Tanzila

    2016-06-01

    Standard database is the essential requirement to compare the performance of image analysis techniques. Hence the main issue in dental image analysis is the lack of available image database which is provided in this paper. Periapical dental X-ray images which are suitable for any analysis and approved by many dental experts are collected. This type of dental radiograph imaging is common and inexpensive, which is normally used for dental disease diagnosis and abnormalities detection. Database contains 120 various Periapical X-ray images from top to bottom jaw. Dental digital database is constructed to provide the source for researchers to use and compare the image analysis techniques and improve or manipulate the performance of each technique.

  15. Evaluation of the Beam Quality of Intraoral X-ray Equipment using Intraoral Standard Films

    International Nuclear Information System (INIS)

    Lee, Sang Sub; Kwon, Hyok Rak; Sim, Woo Hyoun; Oh, Seung Hyoun; Lee, Ji Youn; Jeon, Kug Jin; Kim, Kee Deog; Park, Chang Seo

    2000-01-01

    This study was to evaluate the beam quality of intraoral X-ray equipment used at Yonsei University Dental Hospital (YUDH) using the half value layer (HVL) and the characteristic curve of intraoral standard X-ray film. The study was done using the intraoral X-ray equipment used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. Most of the HVLs of intraoral X-ray equipment were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANPAS 601 model and REX 601 model at operative dentistry department, the X-70S model of prosthodontic dentistry department, and the REX 601 model at the student clinic were relatively low. HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X-ray equipment should be managed in the planned and organized fashion.

  16. Understanding Nickel Thin Film crystallization using X-Ray ...

    African Journals Online (AJOL)

    The microstructures of these Ni films were studied using X-ray diffractometry technique. The X-ray diffraction (XRD) patterns depicted 100% and 42% relative intensity (RI) peaks identified for normal and helical deposited Ni films but none for the zigzag deposited Ni film. Higher degree of crystallinity of Ni was demonstrated ...

  17. Controlled Use of X-Ray in Dental Practice

    Directory of Open Access Journals (Sweden)

    Lesbia Rosa Tirado-Amado

    2015-01-01

    Full Text Available Abstract: Objective: To contribute in an informative and critical way to the promotion of controlled use of X-ray during dental consulting and dental care. Introduction: The practice of dentistry as a health care service requires the use of complementary tools for proper diagnosis, treatment and follow-up in patients with different clinical conditions. For that reason, the use of x-ray by dentists is common and very useful, but it involves radiation exposure to the patient and the dental professional or dental student. Although, often people do not pay attention to this exposition in regard to biological effects, because they are considered too low to generate significant biological effects. Conclusion: It is necessary to consider the risk of accumulative doses for constant exposure in dentist and dental students. Moreover, in patients, because a synergism with other radiations can occur, they can be exposed because of the attention in other areas of health. For these reasons, it is necessary to promote awareness and knowledge on basic aspects of the controlled use of X-ray in the dental care, being also aware of the need to strengthen the knowledge of the basics aspects that lead to decreased risk of biological effects from its proper use in the dental care.

  18. Radiation protection requirements for dental X-ray diagnostic facilities

    International Nuclear Information System (INIS)

    Taschner, P.; Koenig, W.; Andreas, M.; Trinius, W.

    1976-01-01

    On the basis of radiation protection regulations the planning of dental X-ray facilities is discussed considering organizational, technical and structural measures suitable for fulfilling protection requirements. Finally, instructions are given aimed at reducing radiation doses to personnel and patients. (author)

  19. Radiation protection requirements for dental X-ray diagnostic facilities

    Energy Technology Data Exchange (ETDEWEB)

    Taschner, P; Koenig, W [Staatliches Amt fuer Atomsicherheit und Strahlenschutz, Berlin (German Democratic Republic); Andreas, M [Karl-Marx-Universitaet, Leipzig (German Democratic Republic). Fachrichtung Stomatologie; Trinius, W [Karl-Marx-Universitaet, Leipzig (German Democratic Republic). Radiologische Klinik

    1976-03-01

    On the basis of radiation protection regulations the planning of dental X-ray facilities is discussed considering organizational, technical and structural measures suitable for fulfilling protection requirements. Finally, instructions are given aimed at reducing radiation doses to personnel and patients.

  20. Limitations of retarded (bisulfite) x-ray film processing

    International Nuclear Information System (INIS)

    Stoering, J.P.; Dittmore, C.

    1979-01-01

    We demonstrate the limitations of using retarded (bisulfite) developer to abate film sensitivity of x-ray films that have been exposed to intense radiation. We compared the measured densities of a large number of Kodak Type-M x-ray film samples exposed to a known fluence of monochromatic x-rays. These film samples were processed in three separate batches of bisulfite developer mixed in the same proportions. We concluded that reproducible film-density information cannot be obtained using different batches of (bisulfite) developer solutions

  1. Investigation of clinical conditions affecting quality control in a dental X-ray unit

    International Nuclear Information System (INIS)

    Akiyama, Hironori; Koseki, Takakazu; Itagaki, Keisuke; Yotsui, Yoritaka; Gamoh, Shoko; Shimizutani, Kimishige

    2011-01-01

    In this study, to clarify quality control issues in a dental X-ray unit, we surveyed the uniformity and safety of absorbed doses and exposure time from dental X-ray units, and evaluated image quality of intraoral radiography at Osaka Dental University Hospital. Measurements of dose and exposure time were carried out five times and the mean was calculated at twenty-two dental X-ray units in our university hospital using the standard parameters for the mandibular molar region in adults. Intraoral radiography for evaluation of image quality was taken using D-speed films under the standard parameters for the mandibular molar region in adults and E-speed films for pediatric patients. Evaluation of image quality was performed by three oral radiologists. Dose and exposure time differed significantly among units. Image quality of intraoral radiography using D-speed films was not significantly better than that of E-speed films. This study demonstrated that it is necessary to establish a uniform dose and exposure time and to change D-speed films to E-speed films when obtaining intraoral radiography in our hospital. (author)

  2. Evaluation of the shielding of dental X-rays units

    International Nuclear Information System (INIS)

    Medrano, E.; Vega C, H. R.; Letechipia de L, C.; Hernandez D, V. M.; Salas L, M. A.

    2014-08-01

    The capacity of the walls of the dental radio-diagnostic rooms has been determined, to diminish the dose levels during the use of the X-rays equipment s. The study was carried out in the Dentistry Academic Unit of the campus Siglo X XI of the Universidad Autonoma de Zacatecas. The X-rays equipment s are a learning tool for the dentistry students and they are also used for offering health services to the population; for this reason is important to verify that the dose levels outside of the room walls are safe. During the evaluation process were used conservative approaches without prejudice of the thickness necessary in benefit of the radiological protection. Of the evaluation was found that all the walls satisfy their function thoroughly like barriers against the X-rays. (Author)

  3. Thin film soft X-ray absorption filters

    International Nuclear Information System (INIS)

    Stattin, H.

    1992-11-01

    This report discusses the composition, reparation and performance of soft x-ray transmission filters for a water window soft x-ray microscope. Unbacked thin films of aluminum, silver and vanadium/aluminum were made by evaporation on a substrate from which they were released. Measured transmittances agree reasonably well with calculations. The report also includes some related theory and discussions about film preparation methods, film contamination and evaluation methods. 33 refs

  4. Thin film characterisation by advanced X-ray diffraction techniques

    International Nuclear Information System (INIS)

    Cappuccio, G.; Terranova, M.L.

    1996-09-01

    The Fifth School on X-ray diffraction from polycrystalline materials was devoted to thin film characterization by advanced X-ray diffraction techniques. Twenty contributions are contained in this volume; all twenty are recorded in the INIS Database. X-ray diffraction is known to be a powerful analytical tool for characterizing materials and understanding their structural features. The aim of these articles is to illustrate the fundamental contribution of modern diffraction techniques (grazing incidence, surface analysis, standing waves, etc.) to the characterization of thin and ultra-thin films, which have become important in many advanced technologies

  5. Drywall plates evaluation as protection barriers in dental X-rays and mammography facilities

    International Nuclear Information System (INIS)

    Guevara R, V. Y.; Romero C, N.; Berrocal T, M.

    2014-08-01

    In the dental X-rays and mammography facilities, usually lead shielded walls as protective barriers are used. Lead is a good attenuator for X-rays, but has toxic properties and its cost is high. Mammography equipment s emit low-energy photons in the range of 25 keV to 35 keV, on current computers; the primary radiation beam is intercepted by the image receptor. Peri apical dental equipment s emit photons in the range of 50 to 90 keV, their filtration is fixed. These devices emit a collimated beam whose diameter is slightly larger than the diagonal dimension of a standard film of dental X-rays. When a dental x-ray is performed, the radiation beam is partially attenuated by the patient. Drywall is a material consisting of plasterboard between two cardboard layers, being its components gypsum and cellulose generally. It is used in construction for execution of interior walls, ceilings and wall coverings, could also serve as a replacement for lead as well as other materials. In this paper three drywall prototypes (Giplac), formed with 02, 04 and 06 drywall layers (13, 16 and 20 cm of thickness respectively) were tested as barriers against primary and secondary X-ray radiation that come from dental and mammography equipment s. The results show that the drywall prototype, 02 layers, efficiently attenuates the secondary radiation beam produced by conventional mammography equipment. And the prototype 04 and 06 layers, efficiently attenuates the primary radiation beam produced by peri apical dental equipment. (author)

  6. Measurements of X ray absorbed doses to dental patients in two dental X ray units in Nigeria

    International Nuclear Information System (INIS)

    Ogundare, F.O.; Oni, O.M.; Balogun, F.A.

    2002-01-01

    Measurements of absorbed doses from radiographic examinations to various anatomical sites in the head and neck of patients with an average age of 45 years using intra-oral dental radiography have been carried out. LiF (TLD-100) dosemeters were used for the measurements of the absorbed dose. The measured absorbed doses to the various anatomical sites in the two units are reported, discussed and compared with results from the literature. Quality control measurements were also performed using a Victoreen quality control test device on the X ray units. The tube voltage accuracies for the two units were found to be within acceptable limits (less than ±10%). On the other hand the exposure time accuracies for these units have large deviations (>20%). These results and those that have been reported in the literature may be an indication that high patient doses are common in most dental X ray centres and countries. As a result of this, regular compliance and performance checks of dental diagnostic X ray equipment are essential in order to ensure proper performance and to minimise unnecessary patient and operator doses. (author)

  7. X-ray film cassette and method of making

    International Nuclear Information System (INIS)

    1980-01-01

    An x-ray film cassette which is capable of providing forces on the film that vary across the surface of the cassette is described. Methods of manufacture are discussed. The system is of particular use when large area films are used in conjunction with intensifying screens. (U.K.)

  8. Impact of X-ray irradiation on PMMA thin films

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Saman, E-mail: saman.khan343@gmail.com [Physics Department, University of Engineering and Technology, Lahore (Pakistan); Rafique, Muhammad Shahid [Physics Department, University of Engineering and Technology, Lahore (Pakistan); Anjum, Safia [Physics Department, Lahore College for Woman University, Lahore (Pakistan); Hayat, Asma [Physics Department, University of Engineering and Technology, Lahore (Pakistan); Iqbal, Nida [Faculty of Biomedical Engineering and Health Science, Universiti Teknologi Malaysia (UTM) (Malaysia)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer PMMA thin films were deposited at 300 Degree-Sign C and 500 Degree-Sign C using PLD technique. Black-Right-Pointing-Pointer These films were irradiated with different fluence of laser produced X-rays. Black-Right-Pointing-Pointer Irradiation affects the ordered packing as well as surface morphology of film. Black-Right-Pointing-Pointer Hardness of film decreases up to certain value of X-ray fluence. Black-Right-Pointing-Pointer Absorption in UV-visible range exhibits a non linear behavior. - Abstract: The objective of this project is to explore the effect of X-ray irradiation of thin polymeric films deposited at various substrate temperatures. pulsed laser deposition (PLD) technique is used for the deposition of PMMA thin films on glass substrate at 300 Degree-Sign C and 500 Degree-Sign C. These films have been irradiated with various X-rays fluences ranging from 2.56 to 5.76 mJ cm{sup -2}. Characterization of the films (before and after the irradiation) is done with help of X-ray Diffractrometer, Optical Microscope, Vickers hardness tester and UV-vis spectroscopy techniques. From XRD data, it is revealed that ordered packing has been improved for the films deposited at 300 Degree-Sign C. However after irradiation the films exhibited the amorphous behavior regardless of the X-ray fluence. Film deposited at 500 Degree-Sign C shows amorphous structure before and after irradiation. Hardness and particle size of thin film have also increased with the increasing substrate temperature. However, the irradiation has reverse effect i.e. the particle size as well as the hardness has reduced. Irradiation has also enhanced the absorption in the UV-visible region.

  9. Impact of X-ray irradiation on PMMA thin films

    International Nuclear Information System (INIS)

    Iqbal, Saman; Rafique, Muhammad Shahid; Anjum, Safia; Hayat, Asma; Iqbal, Nida

    2012-01-01

    Highlights: ► PMMA thin films were deposited at 300 °C and 500 °C using PLD technique. ► These films were irradiated with different fluence of laser produced X-rays. ► Irradiation affects the ordered packing as well as surface morphology of film. ► Hardness of film decreases up to certain value of X-ray fluence. ► Absorption in UV–visible range exhibits a non linear behavior. - Abstract: The objective of this project is to explore the effect of X-ray irradiation of thin polymeric films deposited at various substrate temperatures. pulsed laser deposition (PLD) technique is used for the deposition of PMMA thin films on glass substrate at 300 °C and 500 °C. These films have been irradiated with various X-rays fluences ranging from 2.56 to 5.76 mJ cm −2 . Characterization of the films (before and after the irradiation) is done with help of X-ray Diffractrometer, Optical Microscope, Vickers hardness tester and UV–vis spectroscopy techniques. From XRD data, it is revealed that ordered packing has been improved for the films deposited at 300 °C. However after irradiation the films exhibited the amorphous behavior regardless of the X-ray fluence. Film deposited at 500 °C shows amorphous structure before and after irradiation. Hardness and particle size of thin film have also increased with the increasing substrate temperature. However, the irradiation has reverse effect i.e. the particle size as well as the hardness has reduced. Irradiation has also enhanced the absorption in the UV–visible region.

  10. [Evaluation of dental X-ray apparatus in terms of patient exposure to ionizing radiation].

    Science.gov (United States)

    Olszewski, Jerzy; Wrzesień, Małgorzata

    2017-06-27

    The use of X-ray in dental procedures causes exposure of the patient to ionizing radiation. This exposure depends primarily on the parameters used in tooth examination. The aim of the study was to determine the patients exposure and to assess the technical condition of X-ray tubes. Seventeen hundred dental offices were covered by the questionnaire survey and 740 questionnaires were sent back. Direct measurements were performed in 100 units by using the thermoluminescent detectors and X-ray films. The results showed that the most commonly used exposure time is 0.22±0.16 s. The average entrance dose for the parameters used most commonly by dentists is 1.7±1.4 mGy. The average efficiency of X-ray tube estimated on the basis of exposures is 46.5±23.7 μGy/mAs. The study results indicate that the vast majority of X-ray tubes meet the requirements specified in the binding regulations. Med Pr 2017;67(4):491-496. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  11. X-ray pickup device for dental radiography

    International Nuclear Information System (INIS)

    Weiss, M.E.

    1980-01-01

    The X-ray tube has got a tubular extension within which a W-shaped target is arranged and which can be inserted into the mouth opening of the patient. The target is inclined with respect to the axis of the beam of electrons striking it in such a way, that the X-radiation emitted by it is received either by the upper or the lower row of teeth, including the root area. A screen mounted on the extension causes only these semicircular areas to be irradiated. An X-ray film holder is also fastened to the extension and covers mouth and cheeks of the patient from outside. The focal spot on the target is adjustable so that a sharp picture can be produced. (RW) [de

  12. Densitometric evaluation of intraoral x-ray films: Ektaspeed versus Ultraspeed

    International Nuclear Information System (INIS)

    Kaffe, I.; Littner, M.M.; Kuspet, M.E.

    1984-01-01

    Recently a new speed E intraoral dental x-ray film was introduced by the Eastman Kodak Company in order to reduce the radiation dose to the patient. In the present study the new higher-speed EP21 film was compared with the speed D DF58 film with regard to speed and quality (fog plus base, sharpness, resolution, and contrast) of the resulting images. Results showed no deterioration in the image with 50% dose reduction when the EP21 film was used as compared to the DF58 film. Therefore, this new type of film is highly recommended for routine radiographic examinations

  13. An Intraoral Miniature X-ray Tube Based on Carbon Nanotubes for Dental Radiography

    OpenAIRE

    Hyun Jin Kim; Hyun Nam Kim; Hamid Saeed Raza; Han Beom Park; Sung Oh Cho

    2016-01-01

    A miniature X-ray tube based on a carbon-nanotube electron emitter has been employed for the application to a dental radiography. The miniature X-ray tube has an outer diameter of 7 mm and a length of 47 mm. The miniature X-ray tube is operated in a negative high-voltage mode in which the X-ray target is electrically grounded. In addition, X-rays are generated only to the teeth directions using a collimator while X-rays generated to other directions are shielded. Hence, the X-ray tube can be ...

  14. Hard X-ray quantum optics in thin films nanostructures

    International Nuclear Information System (INIS)

    Haber, Johann Friedrich Albert

    2017-05-01

    This thesis describes quantum optical experiments with X-rays with the aim of reaching the strong-coupling regime of light and matter. We make use of the interaction which arises between resonant matter and X-rays in specially designed thin-film nanostructures which form X-ray cavities. Here, the resonant matter are Tantalum atoms and the Iron isotope "5"7Fe. Both limit the number of modes available to the resonant atoms for interaction, and enhances the interaction strength. Thus we have managed to observe a number of phenomena well-known in quantum optics, which are the building blocks for sophisticated applications in e.g. metrology. Among these are the strong coupling of light and matter and the concurrent exchange of virtual photons, often called Rabi oscillations. Furthermore we have designed and tested a type of cavity hitherto unused in X-ray optics. Finally, we develop a new method for synchrotron Moessbauer spectroscopy, which not only promises to yield high-resolution spectra, but also enables the retrieval of the phase of the scattered light. The results open new avenues for quantum optical experiments with X-rays, particularly with regards to the ongoing development of high-brilliance X-ray free-electron lasers.

  15. Hard X-ray quantum optics in thin films nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Haber, Johann Friedrich Albert

    2017-05-15

    This thesis describes quantum optical experiments with X-rays with the aim of reaching the strong-coupling regime of light and matter. We make use of the interaction which arises between resonant matter and X-rays in specially designed thin-film nanostructures which form X-ray cavities. Here, the resonant matter are Tantalum atoms and the Iron isotope {sup 57}Fe. Both limit the number of modes available to the resonant atoms for interaction, and enhances the interaction strength. Thus we have managed to observe a number of phenomena well-known in quantum optics, which are the building blocks for sophisticated applications in e.g. metrology. Among these are the strong coupling of light and matter and the concurrent exchange of virtual photons, often called Rabi oscillations. Furthermore we have designed and tested a type of cavity hitherto unused in X-ray optics. Finally, we develop a new method for synchrotron Moessbauer spectroscopy, which not only promises to yield high-resolution spectra, but also enables the retrieval of the phase of the scattered light. The results open new avenues for quantum optical experiments with X-rays, particularly with regards to the ongoing development of high-brilliance X-ray free-electron lasers.

  16. Magnetic x-ray dichroism in ultrathin epitaxial films

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, J.G.; Goodman, K.W. [Lawrence Berkeley National Lab., CA (United States); Cummins, T.R. [Univ. of Missouri, Rolla, MO (United States)] [and others

    1997-04-01

    The authors have used Magnetic X-ray Linear Dichroism (MXLD) and Magnetic X-ray Circular Dichroism (MXCD) to study the magnetic properties of epitaxial overlayers in an elementally specific fashion. Both MXLD and MXCD Photoelectron Spectroscopy were performed in a high resolution mode at the Spectromicroscopy Facility of the ALS. Circular Polarization was obtained via the utilization of a novel phase retarder (soft x-ray quarter wave plate) based upon transmission through a multilayer film. The samples were low temperature Fe overlayers, magnetic alloy films of NiFe and CoNi, and Gd grown on Y. The authors results include a direct comparison of high resolution angle resolved Photoelectron Spectroscopy performed in MXLD and MXCD modes as well as structural studies with photoelectron diffraction.

  17. Magnetic x-ray dichroism in ultrathin epitaxial films

    International Nuclear Information System (INIS)

    Tobin, J.G.; Goodman, K.W.; Cummins, T.R.

    1997-01-01

    The authors have used Magnetic X-ray Linear Dichroism (MXLD) and Magnetic X-ray Circular Dichroism (MXCD) to study the magnetic properties of epitaxial overlayers in an elementally specific fashion. Both MXLD and MXCD Photoelectron Spectroscopy were performed in a high resolution mode at the Spectromicroscopy Facility of the ALS. Circular Polarization was obtained via the utilization of a novel phase retarder (soft x-ray quarter wave plate) based upon transmission through a multilayer film. The samples were low temperature Fe overlayers, magnetic alloy films of NiFe and CoNi, and Gd grown on Y. The authors results include a direct comparison of high resolution angle resolved Photoelectron Spectroscopy performed in MXLD and MXCD modes as well as structural studies with photoelectron diffraction

  18. Sensitometric curve of radiographic films by X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Gonçalves, E.A.S., E-mail: elicardo.goncalves@ifrj.edu.br [Instituto Federal do Rio de Janeiro (IFRJ), RJ (Brazil); Oliveira, D.F.; Anjos, M.J. dos; Oliveira, L.F. de [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil); Lopes, R.T. [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Radiographic film exposure is traditionally measured by the transmittance of a beam of light through the film. There are many mathematical and computational models to characterize the curve behavior and its properties, but almost none of them considers the limitations caused by the equipment used. As long as exposure in film increases, light intensity measured after the film decreases in a way that from a certain exposure, light could not be distinguished from any kind of noise. This work aims to propose x-ray fluorescence as a solution for better measure high exposed films and show how it could be modeled mathematically. (author)

  19. Radiation doses for X-ray diagnosis teeth in dental medicine

    International Nuclear Information System (INIS)

    Direkov, Lyubomir

    2009-01-01

    X-rays are the first ionizing radiation, which are applied in medicine for diagnostic radiology and X-ray therapy. While in the beginning they are mainly used for X-ray photos of the chest /lungs and in severe fractures of the limbs, then in recent years they are widely applied in diagnostics of teeth in dental medicine. Considering that caries is a widespread disease, both in children and adults, and it requires repeated x-ray photographs of the damaged teeth for the individual, the total radiation doses, which reflect on people from the X-rays are at high values. In order to reduce external exposure to other organs /mainly thyroid gland/ by X-ray pictures of teeth, it should be used with special lead aprons with large coefficient of reduction. Keywords: doses of radiation, X-ray machines, dental, x-ray pictures of teeth, protection sources

  20. Positioning X-Ray Film Inside A Flow Splitter

    Science.gov (United States)

    Darter, Charles; Pierce, Darryl

    1990-01-01

    Simple and inexpensive tool ensures secure placement for radiographic inspection. Holder places film positively and securely for x-ray inspection inside sections of tube with splitter welds. V-shaped piece of film fits on arms of holder. With arms squeezed together, holder inserted in opening of neck. Arms of holder cut from 0.020-in. (0.51-mm) thick stock of unspecified material.

  1. A miniature X-ray tube based on carbon nanotube for an intraoral dental radiography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Jin; Park, Han Beom; Lee, Ju Hyuk; Cho, Sung Oh [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    The number of human teeth that can be radiographically taken is limited. Moreover, at least two X-ray shots are required to get images of teeth from both sides of the mouth. In order to overcome the disadvantages of conventional dental radiography, a dental radiograph has been proposed in which an X-ray tube is inserted into the mouth while an X-ray detector is placed outside the mouth. The miniature X-ray tube is required small size to insert into the mouth. Recently, we have fabricated a miniature x-ray tube with the diameter of 7 mm using a carbon nanotube (CNT) field. But, commercialized miniature X-ray tube were adopted a thermionic type using tungsten filament. The X-ray tubes adopted thermionic emission has a disadvantage of increasing temperature of x-ray tube. So it need to cooling system to cool x-ray tube. On the other hands, X-ray tubes adopted CNT field emitters don't need cooling systems because electrons are emitted from CNT by applying high voltage without heating. We have developed the miniature x-ray tube that produce x-ray with uniform spatial distribution based on carbon nanotube field emitters. The fabricated miniature x-ray tube can be stably and reliably operated at 50kV without any vacuum pump. The developed miniature X-ray tube was applied for intraoral dental radiography that employs an intra-oral CNT-based miniature X-ray tube and extra-oral X-ray detectors. An X-ray image of many teeth was successfully obtained by a single X-ray shot using the intra-oral miniature X-ray tube system. Furthermore, images of both molar teeth of pig were simultaneously obtained by a single X-ray shot. These results show that the intraoral dental radiography, which employs an intraoral miniature X-ray tube and an extraoral X-ray detector, performs better than conventional dental radiography.

  2. A miniature X-ray tube based on carbon nanotube for an intraoral dental radiography

    International Nuclear Information System (INIS)

    Kim, Hyun Jin; Park, Han Beom; Lee, Ju Hyuk; Cho, Sung Oh

    2016-01-01

    The number of human teeth that can be radiographically taken is limited. Moreover, at least two X-ray shots are required to get images of teeth from both sides of the mouth. In order to overcome the disadvantages of conventional dental radiography, a dental radiograph has been proposed in which an X-ray tube is inserted into the mouth while an X-ray detector is placed outside the mouth. The miniature X-ray tube is required small size to insert into the mouth. Recently, we have fabricated a miniature x-ray tube with the diameter of 7 mm using a carbon nanotube (CNT) field. But, commercialized miniature X-ray tube were adopted a thermionic type using tungsten filament. The X-ray tubes adopted thermionic emission has a disadvantage of increasing temperature of x-ray tube. So it need to cooling system to cool x-ray tube. On the other hands, X-ray tubes adopted CNT field emitters don't need cooling systems because electrons are emitted from CNT by applying high voltage without heating. We have developed the miniature x-ray tube that produce x-ray with uniform spatial distribution based on carbon nanotube field emitters. The fabricated miniature x-ray tube can be stably and reliably operated at 50kV without any vacuum pump. The developed miniature X-ray tube was applied for intraoral dental radiography that employs an intra-oral CNT-based miniature X-ray tube and extra-oral X-ray detectors. An X-ray image of many teeth was successfully obtained by a single X-ray shot using the intra-oral miniature X-ray tube system. Furthermore, images of both molar teeth of pig were simultaneously obtained by a single X-ray shot. These results show that the intraoral dental radiography, which employs an intraoral miniature X-ray tube and an extraoral X-ray detector, performs better than conventional dental radiography

  3. An Intraoral Miniature X-ray Tube Based on Carbon Nanotubes for Dental Radiography

    Directory of Open Access Journals (Sweden)

    Hyun Jin Kim

    2016-06-01

    Full Text Available A miniature X-ray tube based on a carbon-nanotube electron emitter has been employed for the application to a dental radiography. The miniature X-ray tube has an outer diameter of 7 mm and a length of 47 mm. The miniature X-ray tube is operated in a negative high-voltage mode in which the X-ray target is electrically grounded. In addition, X-rays are generated only to the teeth directions using a collimator while X-rays generated to other directions are shielded. Hence, the X-ray tube can be safely inserted into a human mouth. Using the intra-oral X-ray tube, a dental radiography is demonstrated where the positions of an X-ray source and a sensor are reversed compared with a conventional dental radiography system. X-ray images of five neighboring teeth are obtained and, furthermore, both left and right molar images are achieved by a single X-ray shot of the miniature X-ray tube.

  4. An intraoral miniature x-ray tube based on carbon nanotubes for dental radiography

    International Nuclear Information System (INIS)

    Kim, Hyun Jin; Kim, Hyun Nam; Raza, Hamid Saeed; Park, Han Beom; Cho, Sung Oh

    2016-01-01

    A miniature X-ray tube based on a carbon-nanotube electron emitter has been employed for the application to a dental radiography. The miniature X-ray tube has an outer diameter of 7 mm and a length of 47 mm. The miniature X-ray tube is operated in a negative high-voltage mode in which the X-ray target is electrically grounded. In addition, X-rays are generated only to the teeth directions using a collimator while X-rays generated to other directions are shielded. Hence, the X-ray tube can be safely inserted into a human mouth. Using the intra-oral X-ray tube, a dental radiography is demonstrated where the positions of an X-ray source and a sensor are reversed compared with a conventional dental radiography system. X-ray images of five neighboring teeth are obtained and, furthermore, both left and right molar images are achieved by a single X-ray shot of the miniature X-ray tube

  5. An intraoral miniature x-ray tube based on carbon nanotubes for dental radiography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Jin; Kim, Hyun Nam; Raza, Hamid Saeed; Park, Han Beom; Cho, Sung Oh [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2016-06-15

    A miniature X-ray tube based on a carbon-nanotube electron emitter has been employed for the application to a dental radiography. The miniature X-ray tube has an outer diameter of 7 mm and a length of 47 mm. The miniature X-ray tube is operated in a negative high-voltage mode in which the X-ray target is electrically grounded. In addition, X-rays are generated only to the teeth directions using a collimator while X-rays generated to other directions are shielded. Hence, the X-ray tube can be safely inserted into a human mouth. Using the intra-oral X-ray tube, a dental radiography is demonstrated where the positions of an X-ray source and a sensor are reversed compared with a conventional dental radiography system. X-ray images of five neighboring teeth are obtained and, furthermore, both left and right molar images are achieved by a single X-ray shot of the miniature X-ray tube.

  6. Leakage and scattered radiation from hand-held dental x-ray unit

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Kyung [Dankook Univ. School of Dentistry, Seoul (Korea, Republic of)

    2007-06-15

    To compare the leakage and scattered radiation from hand-held dental X-ray unit with radiation from fixed dental X-ray unit. For evaluation we used one hand-held dental X-ray unit and Oramatic 558 (Trophy Radiologie, France), a fixed dental X-ray unit. Doses were measured with Unfors Multi-O-Meter 512L at the right and left hand levels of X-ray tube head part for the scattered and leakage radiation when human skull DXTTR {iota}{iota}{iota} was exposed to both dental X-ray units. And for the leakage radiation only, doses were measured at the immediately right, left, superior and posterior side of the tube head part when air was exposed. Exposure parameters of hand-held dental X-ray unit were 70 kVp, 3 mA , 0.1 second, and of fixed X-ray unit 70 kVp, 8 mA, 0.45 second. The mean dose at the hand level when human skull DXTTR {iota}{iota}{iota} was exposed with portable X-ray unit 6.39 {mu}Gy, and the mean dose with fixed X-ray unit 3.03 {mu}Gy (p<0.001). The mean dose at the immediate side of the tube head part when air was exposed with portable X-ray unit was 2.97 {mu}Gy and with fixed X-ray unit the mean dose was 0.68 {mu}Gy (p<0.01). The leakage and scattered radiation from hand-held dental radiography was greater than from fixed dental radiography.

  7. Leakage and scattered radiation from hand-held dental x-ray unit

    International Nuclear Information System (INIS)

    Kim, Eun Kyung

    2007-01-01

    To compare the leakage and scattered radiation from hand-held dental X-ray unit with radiation from fixed dental X-ray unit. For evaluation we used one hand-held dental X-ray unit and Oramatic 558 (Trophy Radiologie, France), a fixed dental X-ray unit. Doses were measured with Unfors Multi-O-Meter 512L at the right and left hand levels of X-ray tube head part for the scattered and leakage radiation when human skull DXTTR ΙΙΙ was exposed to both dental X-ray units. And for the leakage radiation only, doses were measured at the immediately right, left, superior and posterior side of the tube head part when air was exposed. Exposure parameters of hand-held dental X-ray unit were 70 kVp, 3 mA , 0.1 second, and of fixed X-ray unit 70 kVp, 8 mA, 0.45 second. The mean dose at the hand level when human skull DXTTR ΙΙΙ was exposed with portable X-ray unit 6.39 μGy, and the mean dose with fixed X-ray unit 3.03 μGy (p<0.001). The mean dose at the immediate side of the tube head part when air was exposed with portable X-ray unit was 2.97 μGy and with fixed X-ray unit the mean dose was 0.68 μGy (p<0.01). The leakage and scattered radiation from hand-held dental radiography was greater than from fixed dental radiography

  8. 21 CFR 1000.60 - Recommendation on administratively required dental x-ray examinations.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Recommendation on administratively required dental x-ray examinations. 1000.60 Section 1000.60 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... Recommendations § 1000.60 Recommendation on administratively required dental x-ray examinations. (a) The Food and...

  9. A Study of the Resolution of Dental Intraoral X-Ray Machines

    International Nuclear Information System (INIS)

    Kim, Seon Ju; Chung, Hyon De

    1990-01-01

    The purpose of this study was to assess the resolution and focal spot size of dental X-ray machines. Fifty dental X-ray machines were selected for measuring resolution and focal spot size. These machines were used in general dental clinics. The time on installation of the X-ray machine varies from 1 years to 10 years. The resolution of these machines was measured with the test pattern. The focal spot size of these machines was measured with the star test pattern. The following results were obtained: 1. The resolution of dental intraoral X-ray machines was not significantly changed in ten years. 2. The focal spot size of dental intraoral X-ray machines was not significantly increased in ten years. The statistical analysis between the mean focal spot size and nominal focal spot size was significant at the 0.05 level about the more than 3 years used machines.

  10. Device for measuring the exposure time in dental X-ray - Cronox

    International Nuclear Information System (INIS)

    Menezes, Claudio J.M.; Santos, Luiz A.P. dos

    2009-01-01

    The Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE) developed a test device for monitoring the X-ray beam in dental equipment to its application in quality control programs. This device, called Odontologic Dosimetric Card (CDO of Cartao Dosimetrico Odontologico in Portuguese) uses thermoluminescent dosimeters (TLD) for the measurement of some parameters of the X-ray beam as the entrance surface dose, the peak tension and half value layer (HVL). Radiographic films record the size of the radiation field. However, the TLD does not allow the assessment of exposure time, a parameter that complements the requirements of the Diretrizes de Protecao Radiologica em Radiodiagnostico Medico e Odontologico of Department of Health in Brazil for such equipment. Thus was developed a system based on sensitivity to ionizing radiation of phototransistors for measurement of exposure time when a patient is put in a clinical dental radiography. The system, called CRONOX was sized to be inserted within the CDO. The results showed that the measuring error had developed for less than 3% when compared to reference values obtained with the Tektronix digital oscilloscope, TDS2022 model. The readings obtained with the CRONOX were also compared with the nominal values selected in the X-ray equipment and with the values measured with the instrument of trade PTW Diavolt Universal. The results showed that the measuring device developed showed a maximum deviation of 5.92% on the nominal value selected, while for the instrument of PTW was 17.86%. (author)

  11. The survey of the surface doses of the dental x-ray machines

    International Nuclear Information System (INIS)

    Lee, Jae Seo; Kang, Byung Cheol; Yoon, Suk Ja

    2005-01-01

    The purpose of this study was to investigate variability of doses with same exposure parameters and evaluate radiographic density according to the variability of doses. Twenty-eight MAX-GLS (Shinhung Co, Seoul, Korea), twenty-one D-60-S (DongSeo Med, Seoul, Korea), and eleven REX-601 (Yoshida Dental MFG, Tokyo, Japan) dental x-ray machines were selected for this study. Surface doses were measured under selected combinations of tube voltage, tube current, exposure time, and constant distance 42 cm from the focal spot to the surface of the Multi-O-meter (Unfors Instrument, Billdal, Sweden). Radiographic densities were measured on the films at maximum, minimum and mean surface doses of each brand of x-ray units. With MAX-GLS, the maximum surface doses were thirteen to fourteen times as much as the minimum surfaces doses. With D-60-S, the maximum surface doses were three to eight times as much as the minimum surface doses. With REX-601, the maximum surface doses were six to ten times as much as the minimum surface doses. The differences in radiographic densities among maximum, mean, and minimum doses were significant (p<0.01). The surface exposure doses of each x-ray machine at the same exposure parameters were different within the same manufacturer's machines.

  12. Glancing angle x-ray studies of oxide films

    International Nuclear Information System (INIS)

    Davenport, A.J.; Isaacs, H.S.

    1989-01-01

    High brightness synchrotron radiation incident at glancing angles has been used to study inhibiting species present in low concentrations in oxide films on aluminum. Glancing incident angle fluorescence measurements give surface-sensitive information on the valence state of elements from the shape of the x-ray absorption edge. Angle-resolved measurements show the depth distribution of the species present. 15 refs., 4 figs

  13. X-ray Tomography using Thin Scintillator Films

    CERN Document Server

    Kozyrev, E A; Lemzyakov, A G; Petrozhitskiy, A V; Popov, A S

    2017-01-01

    2-14 μm thin CsI:Tl scintillation screens with high spatial resolution were prepared by the thermal deposition method for low energy X-ray imaging applications. The spatial resolution was measured as a function of the film thickness. It was proposed that the spatial resolution of the prepared conversion screens can be significantly improved by an additional deposition of a carbon layer.

  14. Dental x-ray validation study: comparison of information from patient interviews and dental charts

    International Nuclear Information System (INIS)

    Preston-Martin, S.; Bernstein, L.; Maldonado, A.A.; Henderson, B.E.; White, S.C.

    1985-01-01

    Information was collected from dentists of a subset of participants in a case-control interview study conducted in Los Angeles County, California, in August 1980-August 1981 to evaluate the relationship of dental x-rays to tumors of the parotid gland. Complete dental charts were available from 142 dentists of 84 cases and from 130 dentists of 79 control. Analysis of data from these interview chart comparisons indicates that recall appears to be unbiased since the measures of agreement between interview and dental chart data are similar for cases and controls. The authors further conclude that interview data alone may be used for case-control comparisons of dental x-ray exposure and would, because of unbiased misclassification, tend to underestimate the relative risks. 12 references, 3 tables

  15. High-contrast x-ray microtomography in dental research

    Science.gov (United States)

    Davis, Graham; Mills, David

    2017-09-01

    X-ray microtomography (XMT) is a well-established technique in dental research. The technique has been used extensively to explore the complex morphology of the root canal system, and to qualitatively and quantitatively evaluate root canal instrumentation and filling efficacy in extracted teeth; enabling different techniques to be compared. Densitometric information can be used to identify and map demineralized tissue resulting from tooth decay (caries) and, in extracted teeth, the method can be used to evaluate different methods of excavation. More recently, high contrast XMT is being used to investigate the relationship between external insults to teeth and the pulpal reaction. When such insults occur, fluid may flow through dentinal tubules as a result of cracking or porosity in enamel. Over time, there is an increase in mineralization along the paths of the tubules from the pulp to the damaged region in enamel and this can be visualized using high contrast XMT. The scanner used for this employs time-delay integration to minimize the effects of detector inhomogeneity in order to greatly increase the upper limit on signal-to-noise ratio that can be achieved with long exposure times. When enamel cracks are present in extracted teeth, the presence of these pathways indicates that the cracking occurred prior to extraction. At high contrast, growth lines are occasionally seen in deciduous teeth which may have resulted from periods of maternal illness. Various other anomalies in mineralization resulting from trauma or genetic abnormalities can also be investigated using this technique.

  16. Wavelet based Image Registration Technique for Matching Dental x-rays

    OpenAIRE

    P. Ramprasad; H. C. Nagaraj; M. K. Parasuram

    2008-01-01

    Image registration plays an important role in the diagnosis of dental pathologies such as dental caries, alveolar bone loss and periapical lesions etc. This paper presents a new wavelet based algorithm for registering noisy and poor contrast dental x-rays. Proposed algorithm has two stages. First stage is a preprocessing stage, removes the noise from the x-ray images. Gaussian filter has been used. Second stage is a geometric transformation stage. Proposed work uses two l...

  17. X-ray diffraction and X-ray standing-wave study of the lead stearate film structure

    Energy Technology Data Exchange (ETDEWEB)

    Blagov, A. E.; Dyakova, Yu. A.; Kovalchuk, M. V.; Kohn, V. G.; Marchenkova, M. A.; Pisarevskiy, Yu. V.; Prosekov, P. A., E-mail: prosekov@crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2016-05-15

    A new approach to the study of the structural quality of crystals is proposed. It is based on the use of X-ray standing-wave method without measuring secondary processes and considers the multiwave interaction of diffraction reflections corresponding to different harmonics of the same crystallographic reflection. A theory of multiwave X-ray diffraction is developed to calculate the rocking curves in the X-ray diffraction scheme under consideration for a long-period quasi-one-dimensional crystal. This phase-sensitive method is used to study the structure of a multilayer lead stearate film on a silicon substrate. Some specific structural features are revealed for the surface layer of the thin film, which are most likely due to the tilt of the upper layer molecules with respect to the external normal to the film surface.

  18. X-ray scattering from thin organic films and multilayer

    International Nuclear Information System (INIS)

    Pietsch, U.; Barberka, T. A.; Geue, Th.; Stoemmer, R.

    1997-01-01

    The real structure of LB-multilayers prepared with fatty-acid salts is dominated by finite-sized scattering aggregates. Their different length scales become visible using AFM. It shows that not the whole substrate is wetted by the film. The molecular order is restricted into domains. These micrometer domains are not homogeneous. They contain mesoscopic subdomains of different heights which vary in steps of double layers. Finally high-resolution AFM-maps display a nearly hexagonal arrangement of molecules within subgrains with a diameter of several 10 nm. This domain structure has to be taken into account when interpreting X-ray diffraction data. The size of the crystalline aggregates is obtained by means of X-ray grazing incidence diffraction. On the mesoscopic scale the domain size is determined by X-ray diffuse scattering experiments. Because Sinha's model fails for the present kind of multilayers, they used another approach for data analysis. The lateral correlation length caused by height fluctuations is estimated without knowledge of a definite correlation function. Additionally the mosaicity of the domain orientation can be taken into account

  19. Radiation protection in dental X-ray surgeries--still rooms for improvement.

    Science.gov (United States)

    Hart, G; Dugdale, M

    2013-03-01

    To illustrate the authors' experience in the provision of radiation protection adviser (RPA)/medical physics expert (MPE) services and critical examination/radiation quality assurance (QA) testing, to demonstrate any continuing variability of the compliance of X-ray sets with existing guidance and of compliance of dental practices with existing legislation. Data was collected from a series of critical examination and routine three-yearly radiation QA tests on 915 intra-oral X-ray sets and 124 panoramic sets. Data are the result of direct measurements on the sets, made using a traceably calibrated Unfors Xi meter. The testing covered the measurement of peak kilovoltage (kVp); filtration; timer accuracy and consistency; X-ray beam size; and radiation output, measured as the entrance surface dose in milliGray (mGy) for intra-oral sets and dose-area product (DAP), measured in mGy.cm(2) for panoramic sets. Physical checks, including mechanical stability, were also included as part of the testing process. The Health and Safety Executive has expressed concern about the poor standards of compliance with the regulations during inspections at dental practices. Thirty-five percent of intra-oral sets exceeded the UK adult diagnostic reference level on at least one setting, as did 61% of those with child dose settings. There is a clear advantage of digital radiography and rectangular collimation in dose terms, with the mean dose from digital sets 59% that of film-based sets and a rectangular collimator 76% that of circular collimators. The data shows the unrealised potential for dose saving in many digital sets and also marked differences in dose between sets. Provision of radiation protection advice to over 150 general dental practitioners raised a number of issues on the design of surgeries with X-ray equipment and critical examination testing. There is also considerable variation in advice given on the need (or lack of need) for room shielding. Where no radiation protection

  20. Summary of: radiation protection in dental X-ray surgeries--still rooms for improvement.

    Science.gov (United States)

    Walker, Anne

    2013-03-01

    To illustrate the authors' experience in the provision of radiation protection adviser (RPA)/medical physics expert (MPE) services and critical examination/radiation quality assurance (QA) testing, to demonstrate any continuing variability of the compliance of X-ray sets with existing guidance and of compliance of dental practices with existing legislation. Data was collected from a series of critical examination and routine three-yearly radiation QA tests on 915 intra-oral X-ray sets and 124 panoramic sets. Data are the result of direct measurements on the sets, made using a traceably calibrated Unfors Xi meter. The testing covered the measurement of peak kilovoltage (kVp); filtration; timer accuracy and consistency; X-ray beam size; and radiation output, measured as the entrance surface dose in milliGray (mGy) for intra-oral sets and dose-area product (DAP), measured in mGy.cm(2) for panoramic sets. Physical checks, including mechanical stability, were also included as part of the testing process. The Health and Safety Executive has expressed concern about the poor standards of compliance with the regulations during inspections at dental practices. Thirty-five percent of intra-oral sets exceeded the UK adult diagnostic reference level on at least one setting, as did 61% of those with child dose settings. There is a clear advantage of digital radiography and rectangular collimation in dose terms, with the mean dose from digital sets 59% that of film-based sets and a rectangular collimator 76% that of circular collimators. The data shows the unrealised potential for dose saving in many digital sets and also marked differences in dose between sets. Provision of radiation protection advice to over 150 general dental practitioners raised a number of issues on the design of surgeries with X-ray equipment and critical examination testing. There is also considerable variation in advice given on the need (or lack of need) for room shielding. Where no radiation protection

  1. Resonant soft x-ray GISAXS on block copolymer films

    Science.gov (United States)

    Wang, Cheng; Araki, T.; Watts, B.; Ade, H.; Hexemer, A.; Park, S.; Russell, T. P.; Schlotter, W. F.; Stein, G. E.; Tang, C.; Kramer, E. J.

    2008-03-01

    Ordered block copolymer thin films may have important applications in modern device fabrication. Current characterization methods such as conventional GISAXS have fixed electron density contrast that can be overwhelmed by surface scattering. However, soft x-rays have longer wavelength, energy dependent contrast and tunable penetration, making resonant GISAXS a very promising tool for probing nanostructured polymer thin films. Our preliminary investigation was performed using PS-b-P2VP block copolymer films on beam-line 5-2 SSRL, and beam-line 6.3.2 at ALS, LBNL. The contrast/sensitivity of the scattering pattern varies significantly with photon energy close to the C K-edge (˜290 eV). Also, higher order peaks are readily observed, indicating hexagonal packing structure in the sample. Comparing to the hard x-ray GISAXS data of the same system, it is clear that resonant GISAXS has richer data and better resolution. Beyond the results on the A-B diblock copolymers, results on ABC block copolymers are especially interesting.

  2. Simulating X-ray diffraction of textured films

    DEFF Research Database (Denmark)

    Breiby, Dag W.; Bunk, Oliver; Andreasen, Jens Wenzel

    2008-01-01

    Computationally efficient simulations of grazing-incidence X-ray diffraction (GIXD) are discussed, with particular attention given to textured thin polycrystalline films on supporting substrates. A computer program has been developed for simulating scattering from thin films exhibiting varying...... degrees of preferred orientation. One emphasized common case is that of a 'fibre' symmetry axis perpendicular to the sample plane, resulting from crystallites having one well defined crystal facet towards the substrate, but no preferred inplane orientation. Peak splitting caused by additional scattering......, the mathematically simplest possible descriptions are sought whenever feasible. The practical use of the program is demonstrated for a selected thin-film example, perylene, which is of relevance for organic electronics....

  3. Terahertz pulsed imaging for the monitoring of dental caries: a comparison with x-ray imaging

    Science.gov (United States)

    Karagoz, Burcu; Kamburoglu, Kıvanc; Altan, Hakan

    2017-07-01

    Dental caries in sliced samples are investigated using terahertz pulsed imaging. Frequency domain terahertz response of these structures consistent with X-ray imaging results show the potential of this technique in the detection of early caries.

  4. Measurement of scattered and transmitted X-rays from intra-oral and panoramic dental X-ray equipment.

    Science.gov (United States)

    Holroyd, John Richard

    2018-04-10

    To quantify the levels of transmitted radiation arising from the use of intra-oral dental X-ray equipment and scattered radiation arising from the use of both intra-oral and panoramic X-ray equipment. Methods: Levels of scattered radiation were measured at 1 m from a phantom, using an 1800 cc ion chamber. Transmitted radiation was measured using both: i) a phantom and Dose Area Product (DAP) meter, ii) a patient and an 1800 cc ion chamber. Results: For intra-oral radiography the patient study gave a maximum transmission of 1.80% (range 0.04% to 1.80%, mean 0.26%) and the phantom study gave a maximum transmission of 6% (range 2% to 6%, mean 5%). The maximum scattered radiation, per unit DAP, was 5.5 nGy (mGy cm2)-1 at 70 kVp and a distance of 1 m. For panoramic radiography the maximum scattered radiation was 9.3 nGy (mGy cm2)-1 at 80 kVp and a distance of 1 m. Conclusions: Typical doses from scattered and transmitted radiation in modern dental practice have been measured and values are presented to enable the calculation of adequate protection measures for dental radiography rooms. Advances in knowledge: Previous studies have used a phantom and measured radiation doses at 1 m from the phantom to determine the radiation dose transmitted through a patient, whereas this study uses both patient and phantom measurements together with a large area dose meter, positioned to capture the entire X-ray beam, to ensure more realistic dose measurements can be made. © 2018 IOP Publishing Ltd.

  5. Lead aprons - should they be used for dental x-rays?

    International Nuclear Information System (INIS)

    Le Heron, J.

    1997-01-01

    When dental x-rays are performed it is now becoming increasingly common for dentists to offer their patients a lead apron to wear. However not all dentists are offering lead aprons. Are some dentists being negligent, and should the use of lead aprons for dental patients be mandatory? This article hopefully answers these questions, and in so doing presents a clear picture of what happens when the dentist presses the exposure button on the x-ray machine. (author). 1 tab

  6. The development and operation of a method for the remote determination of X-ray beam parameters used in dental radiography

    International Nuclear Information System (INIS)

    Hewitt, J.M.

    1984-07-01

    The method described is a part of the Dental Monitoring Service operated by the Board in the UK for the assessment of radiation protection in dental practice. This postal service, which provides a comprehensive survey of dental X-ray sets and radiographic procedures, is undertaken by means of a questionnaire, film cassettes for exposure to the X-ray set and a personal monitoring component to check operator doses. The film cassettes and the methods by which the X-ray beam parameters are obtained are described in detail. The cassettes use radiation monitoring film to realise, by means of measurements of relative transmission through selected copper filters, the extended dynamic range of exposure necessary for accurate indication of the operating kilovoltage and total beam filtration. The standard of the X-ray unit with regard to the relevant regulations and code of practice can then be assessed, and, from the values of radiation dose determined for chosen exposure times, exposure settings for optimum quality radiographs can be recommended where appropriate. Although designed primarily for dental X-ray units, use of the film cassette package may be extended, with suitable calibration, to general diagnostic X-ray survey measurements. (author)

  7. Using computational modeling to compare X-ray tube Practical Peak Voltage for Dental Radiology

    International Nuclear Information System (INIS)

    Holanda Cassiano, Deisemar; Arruda Correa, Samanda Cristine; Monteiro de Souza, Edmilson; Silva, Ademir Xaxier da; Pereira Peixoto, José Guilherme; Tadeu Lopes, Ricardo

    2014-01-01

    The Practical Peak Voltage-PPV has been adopted to measure the voltage applied to an X-ray tube. The PPV was recommended by the IEC document and accepted and published in the TRS no. 457 code of practice. The PPV is defined and applied to all forms of waves and is related to the spectral distribution of X-rays and to the properties of the image. The calibration of X-rays tubes was performed using the MCNPX Monte Carlo code. An X-ray tube for Dental Radiology (operated from a single phase power supply) and an X-ray tube used as a reference (supplied from a constant potential power supply) were used in simulations across the energy range of interest of 40 kV to 100 kV. Results obtained indicated a linear relationship between the tubes involved. - Highlights: • Computational Model was developed to X-ray tube Practical Peak Voltage for Dental Radiology. • The calibration of X-rays tubes was performed using the MCNPX Monte Carlo code. • The energy range was 40–100 kV. • Results obtained indicated a linear relationship between the Dental Radiology and reference X-ray tubes

  8. Recovery of silver from waste photographic x-ray films

    International Nuclear Information System (INIS)

    Nartey, V.K.; Donkor, A.; Fianko, J.R.

    2005-01-01

    In this work, metallic silver has been recovered from disused X-ray films by leaching the silver (Ag) with 50% and 70% nitric acid(HNO 3 ) aqueous solutions. The films were collected from four hospitals in Accra. This method of retrieving Ag is more environmentally friendly compared with the current traditional technique employing dilute sulfuric acid (33%) by the indigenous population to win Ag. More so, the traditional method is characterized by the emission of toxic fuming gases (e.g. sulfur dioxide) and particulates (e.g. lead and arsenic compounds) during the refining of the Ag while reporting.Average yield of recovered Ag was 50.6% following the traditional method whereas 77.0% and 82.9% were obtained using 50% and 70% HNO 3 respectively. (au)

  9. Thin film characterization by total reflection x-ray fluorescence

    International Nuclear Information System (INIS)

    Danel, Adrien; Nolot, Emmanuel; Veillerot, Marc; Olivier, Segolene; Decorps, Tifenn; Calvo-Munoz, Maria-Luisa; Hartmann, Jean-Michel; Lhostis, Sandrine; Kohno, Hiroshi; Yamagami, Motoyuki; Geoffroy, Charles

    2008-01-01

    Sensitive and accurate characterization of films thinner than a few nm used in nanoelectronics represents a challenge for many conventional production metrology tools. With capabilities in the 10 10 at/cm 2 , methods usually dedicated to contamination analysis appear promising, especially Total-reflection X-Ray Fluorescence (TXRF). This study shows that under usual configuration for contamination analysis, with incident angle smaller than the critical angle of the substrate, TXRF signal saturation occurs very rapidly for dense films (below 0.5 nm for HfO 2 films on Si wafers using a 9.67 keV excitation at 0.5 deg.). Increasing the incident angle, the range of linear results can be extended, but on the other hand, the TXRF sensitivity is degraded because of a strong increase of the measurement dead time. On HfO 2 films grown on Si wafers, an incident angle of 0.32 deg. corresponding to a dead time of 95% was used to achieve linear analysis up to 2 nm. Composition analysis by TXRF, and especially the detection of minor elements into thin films, requires the use of a specific incident angle to optimize sensitivity. Although quantitative analyses might require specific calibration, this work shows on Co-based films that the ratio between minor elements (W, P, Mo) and Co taking into account their relative sensitivity factors is a good direct reading of the composition

  10. Problems and image processing in X-ray film digitization

    International Nuclear Information System (INIS)

    Kato, Syousuke; Yoshita, Hisashi; Kuranishi, Makoto; Itoh, Hajime; Mori, Kouichi; Konishi, Minoru

    1992-01-01

    Aiming at the realization of PACS, a study was conducted on the present state of, and various problems associated with, X-ray film digitization using a He-Ne laser-type film digitizer. Image quality was evaluated physically and clinically. With regard to the gradation specificity, the linear specificity was shown in a dynamic range of 4 figures. With regard to resolution specificity, visual evaluation was performed using a Hawlet Chart, with almost no difference being found between the CRT and laser printer output images and the decrease in resolution becoming more pronounced as the sampling pitch became greater. Clinical evaluation was performed with reference to the literature. The general evaluation of the clinicians was that although there was some deterioration for all of the shadows, (I have read this many times, but could not understand the last part.) by performing each of the kinds of image-processing enhancement of diagnostic ability was achieved, with a diagnosis being possible. The problem of unhindered diagnosis due to the development of artifacts from optical interference of the grid images projected onto the clinical pictures and digitizer sampling pitch was studied. As countermeasures, the use of a high density grid and adoption of a low-pass filter were useful in impending the development of artifacts. Regarding the operating problems, the inputting of index information requires a considerable number of manhours and a method of automatic recognition from digital data was introduced to overcome this problem. As future-prospects, the concepts of a practical system of X-ray film digitization and a film-screen system adapted to digitization were described. (author)

  11. Problems and image processing in X-ray film digitization

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Syousuke; Yoshita, Hisashi; Kuranishi, Makoto; Itoh, Hajime; Mori, Kouichi; Konishi, Minoru (Toyama Medical and Pharmaceutical Univ. (Japan). Hospital)

    1992-11-01

    Aiming at the realization of PACS, a study was conducted on the present state of, and various problems associated with, X-ray film digitization using a He-Ne laser-type film digitizer. Image quality was evaluated physically and clinically. With regard to the gradation specificity, the linear specificity was shown in a dynamic range of 4 figures. With regard to resolution specificity, visual evaluation was performed using a Hawlet Chart, with almost no difference being found between the CRT and laser printer output images and the decrease in resolution becoming more pronounced as the sampling pitch became greater. Clinical evaluation was performed with reference to the literature. The general evaluation of the clinicians was that although there was some deterioration for all of the shadows, (I have read this many times, but could not understand the last part.) by performing each of the kinds of image-processing enhancement of diagnostic ability was achieved, with a diagnosis being possible. The problem of unhindered diagnosis due to the development of artifacts from optical interference of the grid images projected onto the clinical pictures and digitizer sampling pitch was studied. As countermeasures, the use of a high density grid and adoption of a low-pass filter were useful in impending the development of artifacts. Regarding the operating problems, the inputting of index information requires a considerable number of manhours and a method of automatic recognition from digital data was introduced to overcome this problem. As future-prospects, the concepts of a practical system of X-ray film digitization and a film-screen system adapted to digitization were described. (author).

  12. Extra-oral dental radiography for disaster victims using a flat panel X-ray detector and a hand-held X-ray generator.

    Science.gov (United States)

    Ohtani, M; Oshima, T; Mimasaka, S

    2017-12-01

    Forensic odontologists commonly incise the skin for post-mortem dental examinations when it is difficult to open the victim's mouth. However, it is prohibited by law to incise dead bodies without permission in Japan. Therefore, we attempted using extra-oral dental radiography, using a digital X-ray equipment with rechargeable batteries, to overcome this restriction. A phantom was placed in the prone position on a table, and three plain dental radiographs were used per case: "lateral oblique radiographs" for left and right posterior teeth and a "contact radiograph" for anterior teeth were taken using a flat panel X-ray detector and a hand-held X-ray generator. The resolving power of the images was measured by a resolution test chart, and the scattered X-ray dose was measured using an ionization chamber-type survey meter. The resolving power of the flat panel X-ray detector was 3.0 lp/mm, which was less than that of intra-oral dental methods, but the three extra-oral plain dental radiographs provided the overall dental information from outside of the mouth, and this approach was less time-consuming. In addition, the higher dose of scattered X-rays was laterally distributed, but the dose per case was much less than that of intra-oral dental radiographs. Extra-oral plain dental radiography can be used for disaster victim identification by dental methods even when it is difficult to open the mouth. Portable and rechargeable devices, such as a flat panel X-ray detector and a hand-held X-ray generator, are convenient to bring and use anywhere, even at a disaster scene lacking electricity and water.

  13. Do Dental X-Rays Induce Genotoxicity and Cytotoxicity in Oral Mucosa Cells? A Critical Review.

    Science.gov (United States)

    Angelieri, Fernanda; Yujra, Veronica Quispe; Oshima, Celina Tizuko Fujiyama; Ribeiro, Daniel Araki

    2017-10-01

    Dental X-rays are widely used in clinical practice, since the technique is an important approach for diagnosing diseases in dental and periodontal tissues. However, it is widely known that radiation is capable of causing damage to cellular systems, such as genotoxicity or cytotoxicity. Thus, the aim of this review was to present a critical analysis regarding the studies published on genotoxicity and cytotoxicity induced by dental X-rays in oral mucosa cells. Such studies have revealed that some oral cell types are more sensitive than others following exposure to dental X-rays. Certainly, this review will contribute to a better understanding of this matter as well as to highlighting perspectives for further studies. Ultimately, such data will promote better safety for both patients and dental professionals. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  14. Preventing bacterial growth on implanted device with an interfacial metallic film and penetrating X-rays.

    Science.gov (United States)

    An, Jincui; Sun, An; Qiao, Yong; Zhang, Peipei; Su, Ming

    2015-02-01

    Device-related infections have been a big problem for a long time. This paper describes a new method to inhibit bacterial growth on implanted device with tissue-penetrating X-ray radiation, where a thin metallic film deposited on the device is used as a radio-sensitizing film for bacterial inhibition. At a given dose of X-ray, the bacterial viability decreases as the thickness of metal film (bismuth) increases. The bacterial viability decreases with X-ray dose increases. At X-ray dose of 2.5 Gy, 98% of bacteria on 10 nm thick bismuth film are killed; while it is only 25% of bacteria are killed on the bare petri dish. The same dose of X-ray kills 8% fibroblast cells that are within a short distance from bismuth film (4 mm). These results suggest that penetrating X-rays can kill bacteria on bismuth thin film deposited on surface of implant device efficiently.

  15. Dental x-rays and the risk of thyroid cancer: A case-control study

    International Nuclear Information System (INIS)

    Memon, Anjum; Godward, Sara; Williams, Dillwyn; Siddique, Iqbal; Al-Saleh, Khalid

    2010-01-01

    The thyroid gland is highly susceptible to radiation carcinogenesis and exposure to high-dose ionising radiation is the only established cause of thyroid cancer. Dental radiography, a common source of low-dose diagnostic radiation exposure in the general population, is often overlooked as a radiation hazard to the gland and may be associated with the risk of thyroid cancer. An increased risk of thyroid cancer has been reported in dentists, dental assistants, and x-ray workers; and exposure to dental x-rays has been associated with an increased risk of meningiomas and salivary tumours. Methods. To examine whether exposure to dental x-rays was associated with the risk of thyroid cancer, we conducted a population-based case-control interview study among 313 patients with thyroid cancer and a similar number of individually matched (year of birth ± three years, gender, nationality, district of residence) control subjects in Kuwait. Results. Conditional logistic regression analysis, adjusted for other upper-body x-rays, showed that exposure to dental x-rays was significantly associated with an increased risk of thyroid cancer (odds ratio = 2.1, 95% confidence interval: 1.4, 3.1) (p=0.001) with a dose-response pattern (p for trend <0.0001). The association did not vary appreciably by age, gender, nationality, level of education, or parity. Discussion. These findings, based on self-report by cases/controls, provide some support to the hypothesis that exposure to dental x-rays, particularly multiple exposures, may be associated with an increased risk of thyroid cancer; and warrant further study in settings where historical dental x-ray records may be available.

  16. Dental x-rays and the risk of thyroid cancer: A case-control study

    Energy Technology Data Exchange (ETDEWEB)

    Memon, Anjum (Div. of Primary Care and Public Health, Brighton and Sussex Medical School (United Kingdom)), E-mail: a.memon@bsms.ac.uk; Godward, Sara (Dept. of Public Health and Primary Care, Univ. of Cambridge (United Kingdom)); Williams, Dillwyn (Thyroid Carcinogenesis Research Group, Strangeways Research Laboratories, Univ. of Cambridge (United Kingdom)); Siddique, Iqbal (Dept. of Medicine, Faculty of Medicine, Kuwait Univ. (Kuwait)); Al-Saleh, Khalid (Kuwait Cancer Control Centre, Ministry of Health (Kuwait))

    2010-05-15

    The thyroid gland is highly susceptible to radiation carcinogenesis and exposure to high-dose ionising radiation is the only established cause of thyroid cancer. Dental radiography, a common source of low-dose diagnostic radiation exposure in the general population, is often overlooked as a radiation hazard to the gland and may be associated with the risk of thyroid cancer. An increased risk of thyroid cancer has been reported in dentists, dental assistants, and x-ray workers; and exposure to dental x-rays has been associated with an increased risk of meningiomas and salivary tumours. Methods. To examine whether exposure to dental x-rays was associated with the risk of thyroid cancer, we conducted a population-based case-control interview study among 313 patients with thyroid cancer and a similar number of individually matched (year of birth +- three years, gender, nationality, district of residence) control subjects in Kuwait. Results. Conditional logistic regression analysis, adjusted for other upper-body x-rays, showed that exposure to dental x-rays was significantly associated with an increased risk of thyroid cancer (odds ratio = 2.1, 95% confidence interval: 1.4, 3.1) (p=0.001) with a dose-response pattern (p for trend <0.0001). The association did not vary appreciably by age, gender, nationality, level of education, or parity. Discussion. These findings, based on self-report by cases/controls, provide some support to the hypothesis that exposure to dental x-rays, particularly multiple exposures, may be associated with an increased risk of thyroid cancer; and warrant further study in settings where historical dental x-ray records may be available.

  17. X-ray diffractometer configurations for thin film analysis

    International Nuclear Information System (INIS)

    Haase, A.

    1996-01-01

    A presentation of various configurations of focusing Seemann-Bohlin diffractometer, parafocusing Bragg-Brentano diffractometer and parallel beam are demonstrated. Equipped with different thin film attachments a comparison to conventional measurements are given. The application of different detector types like scintillation, gas proportional, electroluminescence (LUX) and solid state are described. Typical instrument set-ups for reflectometry, grazing incidence diffraction, total reflection, high resolution X-ray diffraction are explained. Different elements like slits, soller slits, pinhole collimators, crystal monochromators, monofiber (FOX) and polycapillaries (multifiber lens, Kumakhov lens'), flat or curved multilayer with constant or variable d-spacing, and their combinations are presented. The comparison of different beam conditioners in peak-to-background ratios are given. Wavelength dispersive scans show the energy discrimination possibilities of different beam optics

  18. X-ray diffractometer configurations for thin film analysis

    Energy Technology Data Exchange (ETDEWEB)

    Haase, A [Rich. Seifert and Co., Analytical X-ray Systems, Ahrensburg (Germany)

    1996-09-01

    A presentation of various configurations of focusing Seemann-Bohlin diffractometer, parafocusing Bragg-Brentano diffractometer and parallel beam are demonstrated. Equipped with different thin film attachments a comparison to conventional measurements are given. The application of different detector types like scintillation, gas proportional, electroluminescence (LUX) and solid state are described. Typical instrument set-ups for reflectometry, grazing incidence diffraction, total reflection, high resolution X-ray diffraction are explained. Different elements like slits, soller slits, pinhole collimators, crystal monochromators, monofiber (FOX) and polycapillaries (multifiber lens, Kumakhov lens`), flat or curved multilayer with constant or variable d-spacing, and their combinations are presented. The comparison of different beam conditioners in peak-to-background ratios are given. Wavelength dispersive scans show the energy discrimination possibilities of different beam optics.

  19. Health risk assessment of doses to patients\\' eyes from dental X-ray ...

    African Journals Online (AJOL)

    The skin entry dose to patients\\' eyes during dental x-ray examination was carried out on one hundred and ten patients comprising infants and adult of both sexes. The dose measurements was performed at Alpha dental centre, Ibadan, using Lithium fluoride thermoluminiscent dosimeters (TLD). The results of the study ...

  20. X-Ray pictures of the developmental anomalis of the hard dental tissue

    International Nuclear Information System (INIS)

    Cecetkova, A.; Ondrasovicova, J.

    2008-01-01

    Dental anomalies are rare lessions of the hard dental tissue. They are as symptoms varies of the syndromes. They are as follow: hyperdoncia, hypodoncia, oligodoncia, anodoncia, mesiodens, macrodoncia and microdoncia. All of the above anomalis are detected by X-ray diagnostics ( intraoral and extra-oral radiography ). (authors)

  1. Recovery of silver from used X-ray film using alkaline protease from ...

    African Journals Online (AJOL)

    Silver is an important industrial metal used in several areas such as photographic and x-ray films, jewelries, silver wares and electronic objects. Silver is used for photographic film/x-ray film because of its matchless quality as a light-sensitive material for making a photographic image. Silver is not destroyed in the ...

  2. Reflectivity and diffraction of X rays applied to organic thin films

    International Nuclear Information System (INIS)

    Rieutord, Francois

    1987-01-01

    This research thesis reports the study of organic thin films by using X-ray-based technologies, and more particularly X-ray reflectivity. After some recalls on X ray diffraction, and on the fabrication of Langmuir-Blodgett films, the author shows how, by combining three X-ray-based techniques, it is possible to study a volume structure of a thin film. He describes the technique of measurement by X- ray reflexivity, its experimental implementation, and methods for result interpretation. In the next part, the author reports the study of peculiar interference effects which are noticed in reflexivity on Langmuir-Blodgett films, and then describes the nature of these films by correlating results of X ray reflexivity with direct observations performed by electronic microscopy on replica [fr

  3. Facility for testing and certification of medical x-ray films at BARC

    International Nuclear Information System (INIS)

    Sharma, Reena; Jayalakshmi, V.; Nair, C.P.R.

    2006-12-01

    The major problem faced in the x-ray department with regard to x-ray films is the non consistent image quality of x-ray films leading to lesions missed/ wrong diagnosis and as a result retakes of the examination and increased radiation dosage to the patient. This report illustrates the methodology adopted by this Division towards implementation of quality assurance of the basic imaging devices namely the medical x-ray films. The characteristics properties desirable in x-ray films are the qualitative response of the emulsion to standard set of exposure and processing conditions in terms of speed, contrast and density. It should be consistent for exposure conditions in a custom built equipment simulating the quantum and type of energy that would be received by the film during diagnostic examinations. The phantom, geometrical set up and beam quality specifications as per the ISO standards required for x-ray sensitometry have been described in this report. (author)

  4. Tone control of overexposed and underexposed x-ray films by using duplicator

    International Nuclear Information System (INIS)

    Ahn, Myeong Im; Jeon, Jung Soo; Kim, Ok Hwa; Kim, Choon Yul; Bahk, Yong Whee

    1990-01-01

    Not infrequently overexposed or underexposed x-ray films impose difficulty in interpretation necessitating repeated radiography. However, repeated examination is not always possible because of the transfer, discharge, and dying of the patients. Then, retonning of improper films is much desirable especially when such films are of considerable clinical and academical importance. The authors carried out a series of experiment to improve the tone of the overexposed and underexposed x-ray films by different exposure times. During duplicating the overexposed film, the film density because bright and imaging details were improved by increasing the exposure time. Underexposed film, however, did not showing any improvement of imaging details but darkened only of overall film density. Therefore, qualified reproduction of overexposed x-ray film using the x-ray film duplicator was easy to do and valuable in the management of film quality without any damage to the original film

  5. Position statement on use of hand-held portable dental X-ray equipment

    International Nuclear Information System (INIS)

    2014-06-01

    The position statement focuses on justification in the medical field, in particular on the use of hand-held portable dental x-ray equipment. It supplements another HERCA position paper, providing a general overview of the use of all hand-held portable X-ray equipment. Key Messages: - HERCA finds that the use of hand-held portable X-ray devices should be discouraged except in special circumstances. - As a general rule, these devices should only be used in scenarios where an intraoral radiograph is deemed necessary for a patient and the use of a fixed or semi-mobile x-ray unit is impractical, e.g.: - nursing homes, residential care facilities or homes for persons with disabilities; - forensic odontology, - military operations abroad without dental facilities

  6. Cross-sectional imaging with rotational panoramic X-ray machine for preoperative assessment of dental implant site. Comparisons of imaging properties with conventional film tomography and computed tomography

    International Nuclear Information System (INIS)

    Makihara, Masahiro; Nishikawa, Keiichi; Kuroyanagi, Kinya

    2001-01-01

    To clarify the validity of cross-sectional imaging with rotational panoramic x-ray machine for preoperative assessment of the dental implant site, the imaging properties were compared with those of spiral tomography and multi-planer reconstruction (MPR) manipulation of x-ray computed tomography. Cross-sectional imaging of the maxilla and mandible of an edentulous dry skull was performed by each technique at an image layer thickness of 1 mm. Steel spheres were used to identify cross-sectional planes and measure distance. Six oral radiologists scored the image clarity of structures with 5-grade rating scales and measured the distance between images of 2 steel spheres. Each measured distance was divided by the magnification factor. The actual distance was also measured on the skull. The score and the distance were statistically compared. The Spearman's rank correlation coefficients for the score and the absolute values of the difference in distances measured by different observers were calculated as test units to compare inter-observer agreements statistically. The same observation and measurement were repeated to compare intra-observer agreement. Image clarity of the linear tomography available with a panoramic machine was comparable to spiral tomography and superior to MPR, except for the cortical bone on the lingual side. The inter- and intra-observer agreements were comparable. The accuracy for measurement of distance, the inter- and intra-observer agreements were also comparable to the spiral tomography and superior to those of MPR. Therefore, it is concluded that cross-sectional imaging with a rotational panoramic x-ray machine is useful for preoperative assessment of the dental implant site. (author)

  7. Cephalometric landmark detection in dental x-ray images using convolutional neural networks

    Science.gov (United States)

    Lee, Hansang; Park, Minseok; Kim, Junmo

    2017-03-01

    In dental X-ray images, an accurate detection of cephalometric landmarks plays an important role in clinical diagnosis, treatment and surgical decisions for dental problems. In this work, we propose an end-to-end deep learning system for cephalometric landmark detection in dental X-ray images, using convolutional neural networks (CNN). For detecting 19 cephalometric landmarks in dental X-ray images, we develop a detection system using CNN-based coordinate-wise regression systems. By viewing x- and y-coordinates of all landmarks as 38 independent variables, multiple CNN-based regression systems are constructed to predict the coordinate variables from input X-ray images. First, each coordinate variable is normalized by the length of either height or width of an image. For each normalized coordinate variable, a CNN-based regression system is trained on training images and corresponding coordinate variable, which is a variable to be regressed. We train 38 regression systems with the same CNN structure on coordinate variables, respectively. Finally, we compute 38 coordinate variables with these trained systems from unseen images and extract 19 landmarks by pairing the regressed coordinates. In experiments, the public database from the Grand Challenges in Dental X-ray Image Analysis in ISBI 2015 was used and the proposed system showed promising performance by successfully locating the cephalometric landmarks within considerable margins from the ground truths.

  8. The combination of an industrial X-ray-film with a vacuum-adapter instead of a foil-less industrial X-ray-film

    International Nuclear Information System (INIS)

    Kurz, C.S.; Rotte, K.

    1980-01-01

    In clinical routine it was proved, how far an industrial X-ray-film in combination with the low-dose-system gives the same evidence as an foil-less industrial X-ray-film. Patients which had got in the past a mammography at both sides with a foil-less industrial X-ray-film received a mammography at both sides with the low-dose-system. Both X-rays were compared in the following criteria: artefacts, micro-calcifications, structure-differentiation, difinition, contrast, exposure, time of diagnosis and overal impression. Considering an evident dose reduction by the low-dose-system the result is, that a film-foil-combination with a vacuum-adapter is available without impairment of diagnostic evidence in clinical routine. (orig.) [de

  9. The reduction methods of operator's radiation dose for portable dental X-ray machines.

    Science.gov (United States)

    Cho, Jeong-Yeon; Han, Won-Jeong

    2012-08-01

    This study was aimed to investigate the methods to reduce operator's radiation dose when taking intraoral radiographs with portable dental X-ray machines. Two kinds of portable dental X-ray machines (DX3000, Dexcowin and Rextar, Posdion) were used. Operator's radiation dose was measured with an 1,800 cc ionization chamber (RadCal Corp.) at the hand level of X-ray tubehead and at the operator's chest and waist levels with and without the backscatter shield. The operator's radiation dose at the hand level was measured with and without lead gloves and with long and short cones. The backscatter shield reduced operator's radiation dose at the hand level of X-ray tubehead to 23 - 32%, the lead gloves to 26 - 31%, and long cone to 48 - 52%. And the backscatter shield reduced operator's radiation dose at the operator's chest and waist levels to 0.1 - 37%. When portable dental X-ray systems are used, it is recommended to select X-ray machine attached with a backscatter shield and a long cone and to wear the lead gloves.

  10. Settling time of dental x-ray tube head after positioning

    International Nuclear Information System (INIS)

    Yun, Suk Ja; Kang, Byung Cheol; Wang, Se Myung; Koh, Chang Sung

    2002-01-01

    The aim of this study was to introduce a method of obtaining the oscillation graphs of the dental x-ray tube heads relative to time using an accelerometer. An Accelerometer, Piezotron type 8704B25 (Kistler Instrument Co., Amherst, NY, USA) was utilized to measure the horizontal oscillation of the x-ray tube head immediately after positioning the tube head for an intraoral radiograph. The signal from the sensor was transferred to a dynamic signal analyzer, which displayed the magnitude of the acceleration on the Y-axis and time lapse on the X-axis. The horizontal oscillation of the tube head was measured relative to time, and the settling time was also determined on the basis of the acceleration graphs for 6 wall type, 5 floor-fixed type, and 4 mobile type dental x-ray machines. The oscillation graphs showed that tube head movement decreased rapidly over time. The settling time varied with x-ray machine types. Wall-type x-ray machines had a settling time of up to 6 seconds, 5 seconds for fixed floor-types, and 11 seconds for the mobile-types. Using an accelerometer, we obtained the oscillation graphs of the dental x-ray tube head relative to time. The oscillation graph with time can guide the operator to decide upon the optimum exposure moment after xray tube head positioning for better radiographic resolution.

  11. Settling time of dental x-ray tube head after positioning

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Suk Ja; Kang, Byung Cheol [Department of Oral and Maxillofacial Radiology, Chonnam National University, Gwangju (Korea, Republic of); Wang, Se Myung; Koh, Chang Sung [Department of Mechatronics, Kwangju Institute of Science and Technology, Gwangju (Korea, Republic of)

    2002-09-15

    The aim of this study was to introduce a method of obtaining the oscillation graphs of the dental x-ray tube heads relative to time using an accelerometer. An Accelerometer, Piezotron type 8704B25 (Kistler Instrument Co., Amherst, NY, USA) was utilized to measure the horizontal oscillation of the x-ray tube head immediately after positioning the tube head for an intraoral radiograph. The signal from the sensor was transferred to a dynamic signal analyzer, which displayed the magnitude of the acceleration on the Y-axis and time lapse on the X-axis. The horizontal oscillation of the tube head was measured relative to time, and the settling time was also determined on the basis of the acceleration graphs for 6 wall type, 5 floor-fixed type, and 4 mobile type dental x-ray machines. The oscillation graphs showed that tube head movement decreased rapidly over time. The settling time varied with x-ray machine types. Wall-type x-ray machines had a settling time of up to 6 seconds, 5 seconds for fixed floor-types, and 11 seconds for the mobile-types. Using an accelerometer, we obtained the oscillation graphs of the dental x-ray tube head relative to time. The oscillation graph with time can guide the operator to decide upon the optimum exposure moment after xray tube head positioning for better radiographic resolution.

  12. X-ray pick-up device for dental radiography

    International Nuclear Information System (INIS)

    Weiss, M.E.

    1980-01-01

    The X-ray tube has got a tabular extension at the front end of which a W-shaped target is mounted. The target hit by electrons emits X-radiation passing through a ceramic window in the surface area. The extension can be inserted into the mouth opening of the patient. For holding down the tongue and for shielding purposes it has got a device shaped like a sleeve with diverging wings fastened to it. Thex leave the ceramic window uncovered. (orig.) [de

  13. The development of a postal method to assess X-ray beam parameters and image quality in dental radiology

    International Nuclear Information System (INIS)

    Fenton, D.M.

    1994-10-01

    Intraoral radiographs are an extremely valuable diagnostic tool in dentistry. Radiography permits the early detection and diagnosis of dental disease and consequently is used extensively. However, public concern about radiation exposure has increased in recent times. This concern is reflected in national and international law, to the extent that, the basic principles of radiological protection, that is, justification, optimisation and dose limitation are written into law. Furthermore, in Ireland, the regulations, as outlined in the Code of Practice for Radiological Protection in Dentistry, require intraoral dental X-ray machines to perform to certain standards. A report of a direct survey of 164 intraoral dental X-ray machines is given in this study. The survey covered mechanical, electrical as well as radiation safety. Inadequacies with respect to focus to skin distance and timer accuracy were found in 45% and 42% of the machines surveyed. Ninety eight machines were assessed for electrical safety in which 48% were found to be unsafe. The results indicate that a complete assessment of the performance of dental X-ray units in Ireland is required. However, as there are in excess of 800 dental X-ray machines located throughout the country, such an assessment would be very costly for the regulatory authority. The development of a postal method for the assessment of the performance of dental X-ray machines is described in this study. This postal method provides information on the kV, total filtration, beam width and timer linearity and is undertaken by means of a penetrameter and film envelopes for exposure to the X-ray set under examination, together with a questionnaire that requests information on environment in which the machine is located. Using this method an accuracy of +-5% of the actual value was achieved in the measurement of kVp. The penetrameter was also used to assess whether or not the filtration of a particular machine complies with the regulations. This

  14. X-ray film reject rate analysis at eight selected government hospitals ...

    African Journals Online (AJOL)

    admin

    Objective: The purpose of this research was to identify the main causes of film faults as well as the pattern and magnitude of film ... ensure satisfactory performance of radiographic x-ray equipment on a day-to-day basis. Quality assurance programs are primarily concerned with maintaining of X- ray imaging equipment at the ...

  15. The sensitizing phenomenon of X-ray film in the experiment of metals loaded with deuterium

    International Nuclear Information System (INIS)

    Chen Suhe; Wang Dalun; Chen Wenjang; Li Yijun; Fu Yibei; Zhang Xinwei

    1993-01-01

    The sensitizing phenomenon of X-ray film was studied, in metals loaded with deuterium, by a cycle method of temperature and pressure (CMTP). The experimental results showed that the sensitization of X-ray film was derived from the chemical reaction and the anomalous effect of metals loaded with deuterium. (author)

  16. Enhancement of dental x-ray images by two channel image processing

    International Nuclear Information System (INIS)

    Mitra, S.; Yu, T.H.

    1991-01-01

    In this paper, the authors develop a new algorithm for the enhancement of low-contrast details of dental X-ray images using a two channel structure. The algorithm first decomposes an input image in the frequency domain into two parts by filtering: one containing the low frequency components and the other containing the high frequency components. Then these parts are enhanced separately using a transform magnitude modifier. Finally a contrast enhanced image is formed by combining these two processed pats. The performance of the proposed algorithm is illustrated through enhancement of dental X-ray images. The algorithm can be easily implemented on a personal computer

  17. Quality assurance through constancy control for X-ray film processors

    International Nuclear Information System (INIS)

    Weberling, R.

    1982-01-01

    A control method to check the reproduction of X-ray film processors and necessary instruments is presented. The application of a light sensitometer allows the production of test films daily, independent of X-ray exposures, X-ray film cassettes and X-ray intensifying screens. The optical densities on the test films will be read by means of a densitometer and the results are plotted on a special control chart. A limitation through optical densities of +-0,15 for Speed Index and +-0,20 for Contrast Index determines the tolerance variation for X-ray film processors. Targets of this control method are uniform image quality, dose reduction and saving of cost. (orig.) [de

  18. Some complementary results to the granularity of industrial X-ray films

    International Nuclear Information System (INIS)

    Stade, J.

    1987-01-01

    The granularity of industrial x-ray films was examined by measurements of the Wiener spectra. The dependence of the Weiner spectra on film density, type of film, type of developer, energy of the exposing x-radiation, and light exposure, was also investigated. The results revealed that the Weiner spectrum or related quantities were suitable as a tool for measuring the influence of different radiographic parameters on the x-ray film, as well as to characterize its properties. (UK)

  19. Image quality assessment and medical physics evaluation of different portable dental X-ray units.

    Science.gov (United States)

    Pittayapat, Pisha; Oliveira-Santos, Christiano; Thevissen, Patrick; Michielsen, Koen; Bergans, Niki; Willems, Guy; Debruyckere, Deborah; Jacobs, Reinhilde

    2010-09-10

    Recently developed portable dental X-ray units increase the mobility of the forensic odontologists and allow more efficient X-ray work in a disaster field, especially when used in combination with digital sensors. This type of machines might also have potential for application in remote areas, military and humanitarian missions, dental care of patients with mobility limitation, as well as imaging in operating rooms. To evaluate radiographic image quality acquired by three portable X-ray devices in combination with four image receptors and to evaluate their medical physics parameters. Images of five samples consisting of four teeth and one formalin-fixed mandible were acquired by one conventional wall-mounted X-ray unit, MinRay 60/70 kVp, used as a clinical standard, and three portable dental X-ray devices: AnyRay 60 kVp, Nomad 60 kVp and Rextar 70 kVp, in combination with a phosphor image plate (PSP), a CCD, or a CMOS sensor. Three observers evaluated images for standard image quality besides forensic diagnostic quality on a 4-point rating scale. Furthermore, all machines underwent tests for occupational as well as patient dosimetry. Statistical analysis showed good quality imaging for all system, with the combination of Nomad and PSP yielding the best score. A significant difference in image quality between the combination of the four X-ray devices and four sensors was established (p1m: Rextar <0.2 microGy, MinRay <0.1 microGy). The present study demonstrated the feasibility of three portable X-ray systems to be used for specific indications, based on acceptable image quality and sufficient accuracy of the machines and following the standard guidelines for radiation hygiene. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  20. Development of Object Simulator for Radiation Field of Dental X-Rays

    International Nuclear Information System (INIS)

    Silva, L F; Ferreira, F C L; Sousa, F F; Cardoso, L X; Vasconcelos, E D S; Brasil, L M

    2013-01-01

    In dentistry radiography is of fundamental importance to the dentist can make an accurate diagnosis. For this it is necessary to pay attention to the radiological protection of both the professional and the patient and control image quality for an accurate diagnosis. In this work, quality control tests were performed on X-ray machines in private dental intraoral in the municipality of Marabá, where they measured the diameters of the radiation field to see if these machines are in accordance with the recommendations, thus preventing the patient is exposed to a radiation field higher than necessary. We will study the results of each X-ray machine evaluated. For this we created a phantom to assess the size of the radiation field of X-ray dental, where we measure the radiation field of each device to see if they are in accordance with the recommendations of the ordinance No. 453/98 – MS

  1. First do no harm - The impact of financial incentives on dental X-rays

    NARCIS (Netherlands)

    Chalkley, M.; Listl, S.

    2018-01-01

    This article assesses the impact of dentist remuneration on the incidence of potentially harmful dental X-rays. We use unique panel data which provide details of 1.3 million treatment claims by Scottish NHS dentists made between 1998 and 2007. Controlling for unobserved heterogeneity of both

  2. Thin film characterisation by advanced X-ray diffraction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cappuccio, G; Terranova, M L [eds.; INFN, Laboratori Nazionali di Frascati, Rome (Italy)

    1996-09-01

    This report described the papers presented at the 5. School on X-ray diffraction from polycrystalline materials held at Frascati (Rome) in 2-5 October 1996. A separate abstract was prepared for each of the papers.

  3. The X-ray sensitivity of semi-insulating polycrystalline CdZnTe thick films

    International Nuclear Information System (INIS)

    Won, Jae Ho; Kim, Ki Hyun; Suh, Jong Hee; Cho, Shin Hang; Cho, Pyong Kon; Hong, Jin Ki; Kim, Sun Ung

    2008-01-01

    The X-ray sensitivity is one of the important parameters indicating the detector performance. The X-ray sensitivity of semi-insulating polycrystalline CdZnTe:Cl thick films was investigated as a function of electric field, mean photon energy, film thickness, and charge carrier transport parameters and, compared with another promising detector materials. The X-ray sensitivities of the polycrystalline CdZnTe films with 350 μm thickness were about 2.2 and 6.2 μC/cm 2 /R in the ohmic-type and Schottky-type detector at 0.83 V/μm, respectively

  4. Combined ellipsometry and X-ray related techniques for studies of ultrathin organic nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Kraemer, Markus, E-mail: axo@standing-waves.d [Leibniz-Institut fuer Analytische Wissenschaften-ISAS-e.V., Bunsen-Kirchhoff-Str. 11, 44139 Dortmund (Germany); AXO DRESDEN GmbH, Siegfried-Raedel-Str. 31, 01809 Heidenau (Germany); Roodenko, Katy [Leibniz-Institut fuer Analytische Wissenschaften-ISAS-e.V.-Department Berlin, Albert-Einstein-Str. 9, 12489 Berlin (Germany); Laboratory for Surface and Nanostructure Modification, University of Texas at Dallas-NSERL, 800W. Campbell Rd., Richardson, TX 75080 (United States); Pollakowski, Beatrix [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Hinrichs, Karsten [Leibniz-Institut fuer Analytische Wissenschaften-ISAS-e.V.-Department Berlin, Albert-Einstein-Str. 9, 12489 Berlin (Germany); Rappich, Joerg [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Abteilung Silizium-Photovoltaik, Kekulestr. 5, 12489 Berlin (Germany); Esser, Norbert [Leibniz-Institut fuer Analytische Wissenschaften-ISAS-e.V.-Department Berlin, Albert-Einstein-Str. 9, 12489 Berlin (Germany); Bohlen, Alex von; Hergenroeder, Roland [Leibniz-Institut fuer Analytische Wissenschaften-ISAS-e.V., Bunsen-Kirchhoff-Str. 11, 44139 Dortmund (Germany)

    2010-07-30

    Ultrathin nanocomposite films of nitrobenzene on silicon were analyzed by Infrared Spectroscopic Ellipsometry (IRSE), X-ray reflectivity (XRR) and X-ray standing waves (XSW) before and after evaporation of gold. Infrared Spectroscopic Ellipsometry measurements were performed for identification of adsorbates and for investigation of the molecular orientation. Results for film thickness were correlated with XRR measurements. Further, XSW measurements of elements incorporated in nitrobenzene (C, N, and O) were performed with soft X-rays. The combination of the different methods allowed to confirm a model for the electrochemically deposited nitrobenzene films before and after gold evaporation. The characterization by XRR and XSW scans using hard X-rays showed that gold had penetrated into the nitrobenzene film and thus changed density and optical properties of this layer significantly. A depth profile correlated to the electron density is deduced from the XRR measurements. This profile allows to localize-in vertical direction-gold islands within the composite film.

  5. Free focus radiography with miniaturized dental x-ray machines: a comparison of ''midline'' and ''lateral'' techniques

    International Nuclear Information System (INIS)

    Jensen, T.W.

    1983-01-01

    The use of free focus radiography (FFR) employing miniaturized dental x-ray machines with radiation probes has never been generally accepted in dentistry despite its recognized radiographic potential. The present investigation studied ways to improve imaging and lower radiation burdens in dental free focus radiography. Relatively high air exposures ranging from 42,050 mR per film for high-resolution images to 3,214 mR per film for lower-resolution images using a current midline radiographic technique for panoramic FFR were found. In a proposed lateral FFR panoramic technique, reduced exposures ranged from 420 mR per film for high-resolution images to 14 mR per film for lower-resolution images. In each technique the lower exposure was obtained with a rare earth imaging system. A proposed modification of the current midline FFR technique using a rare earth imaging system and heavy added copper filtration was found to produce exposures in the range normally used in dentistry (207 mr), and the resultant image was high in contrast with relatively low detail. A comparison of essential characteristics of midline and lateral FFR techniques failed to identify specific advantages for the midline technique in current use. Lateral exposure modes in dental FFR should receive increased attention in the interest of good imaging and radiation control. It was noted that existing miniaturized dental x-ray machines may have been designed specifically for use of the midline FFR exposure technique, and modification of this equipment to support reliable lateral exposure modes was recommended

  6. X-ray radiation damage of organic semiconductor thin films during grazing incidence diffraction experiments

    Energy Technology Data Exchange (ETDEWEB)

    Neuhold, A., E-mail: alfred.neuhold@tugraz.at [Institute of Solid State Physics, Graz University of Technology, Graz (Austria); Novak, J.; Flesch, H.-G.; Moser, A.; Djuric, T. [Institute of Solid State Physics, Graz University of Technology, Graz (Austria); Grodd, L.; Grigorian, S.; Pietsch, U. [Institute of Physics, University Siegen (Germany); Resel, R. [Institute of Solid State Physics, Graz University of Technology, Graz (Austria)

    2012-08-01

    Since modern synchrotrons with highly intense X-ray beams are in use to investigate organic materials, the stability of soft matter materials during beam exposure is a crucial issue. Grazing incidence X-ray diffraction and specular X-ray reflectivity measurements were performed on thin films of organic semiconducting materials, like poly(3-hexylthiophene) (P3HT), sexithiophene and pentacene. These films were irradiated with an average flux density between 10{sup 15} and 10{sup 16} photons/(s mm{sup 2}) and evidenced a different stability in synchrotron X-ray radiation. The semi-crystalline P3HT showed a clear intensity decrease of the 1 0 0 Bragg peak and 0 2 0 Bragg peak compared to the rather stable diffraction features of the molecular crystals sexithiophene and pentacene. The difference in synchrotron X-ray radiation stability is explained by the interaction of the X-ray beam with the individual chemical components in the molecules as well as by the different crystallinities of the materials. Furthermore, the semi-crystalline P3HT film exhibited an increase of film thickness after irradiation and the surface roughness slightly decreased. To summarize, this study shows a strong influence of synchrotron X-ray radiation to specific organic thin films like e.g. P3HT, while others like pentacene and sexithiophene are observed as quite stable.

  7. Theory of X-ray microcomputed tomography in dental research: application for the caries research

    Directory of Open Access Journals (Sweden)

    Young-Seok Park

    2011-03-01

    Full Text Available Caries remains prevalent throughout modern society and is the main disease in the field of dentistry. Although studies of this disease have used diverse methodology, recently, X-ray microtomography has gained popularity as a non-destructive, 3-dimensional (3D analytical technique, and has several advantages over the conventional methods. According to X-ray source, it is classified as monochromatic or polychromatic with the latter being more widely used due to the high cost of the monochromatic source despite some advantages. The determination of mineral density profiles based on changes in X-ray attenuation is the principle of this method and calibration and image processing procedures are needed for the better image and reproducible measurements. Using this tool, 3D reconstruction is also possible and it enables to visualize the internal structures of dental caries. With the advances in the computer technology, more diverse applications are being studied, such automated caries assessment algorithms.

  8. Surface characterization of selected polymer thin films by total-reflection x-ray fluorescence spectroscopy and x-ray reflectivity

    International Nuclear Information System (INIS)

    Innis, Vallerie Ann A.

    2006-01-01

    Development of available x-ray characterizations tools for grazing incidence techniques was done to be able to probe nano-size thin films. Alignment of a Philips x-ray powder diffractometer was improved to let it perform as an x-ray reflectometer. X-ray reflectometry was coupled with total-reflection x-ray fluorescence spectroscopy. Evaluation of the performance of this grazing incidence techniques was done by preparing polymer thin films of carboxymethylcellulose, carrageenan and polyvinylpyrrolidone (PVP). The thickness of the films were varied by varying the process parameters such as concentration, spin speed and spin time. Angle-dispersive total-reflection x-ray fluorescence spectroscopy profiles of three films showed film formation only in carrageenan and PVP. For both carrageenan and PVP, an increase in concentration yielded a corresponding increase in intensity of the fluorescent or scattered peaks. XRR profiles of carrageenan thin films yielded a mean value for the critical angle close to quartz substrate. Thickness measurements of the prepared carrageenan thin films showed that concentration was the main determinant for final film thickness over the other process parameters. Sulfur fluorescent intensity derived from the TXRF measurement showed a linear relationship with the measured thickness by XRR. For PVP, measured critical angle is lower than quartz. Poor adhesion of the polymer onto the substrate yielded a limited number of thickness measurements made from the XRR profiles. (Author)

  9. Frequency of medical and dental x-ray examinations in the UK. 1997/98

    International Nuclear Information System (INIS)

    Tanner, R.; Wall, B.; Shrimpton, P.

    2000-12-01

    A survey has been performed to assess the numbers of all types of radiological x-ray examination conducted in the UK during the period from April 1997 to March 1998. The survey covers all diagnostic and interventional procedures using x-rays for medical and dental purposes, both within and outside the National Health Service (NHS), but excludes a detailed analysis of magnetic resonance imaging (MRI), ultrasound and nuclear medicine. This is the first such national survey conducted by NRPB since 1983. The results provide a current picture of the pattern of medical x-ray imaging practice in the UK and will allow revised estimates to be made of the collective dose to the population from these procedures. The survey has utilised detailed information available from radiology management systems at a selected sample of 38 English NHS trusts. The different classifications of x-ray procedure have been re-arranged into 62 standardised categories based on anatomical location and whether they were conventional, computed tomography (CT) or interventional procedures. Extrapolation of the sample data to the whole of England was carried out using broad NHS radiology statistics (KH12 returns) for the period of the survey from the Department of Health. Additional data have been obtained covering NHS radiology practice in Wales and Northern Ireland and also for x-ray imaging practice outside NHS hospitals such as that performed in independent hospitals and by dentists and chiropractors. Results are presented giving the annual numbers and relative frequencies of x-ray examinations in the 62 categories and the contributions from radiology practice outside NHS hospitals and from the whole of the UK. Altogether, about 41.5 million medical and dental x-ray examinations were conducted in the UK in 1997/98, corresponding to 704 examinations per 1000 inhabitants. The increase since 1983 for medical examinations conducted in NHS hospitals has just kept pace with the increase in population

  10. Control area around dental x-ray units - dosimetric study I

    International Nuclear Information System (INIS)

    Suric Mihic, M.; Prlic, I.; Milkovic-Kraus, S.; Mestrovic, T.; Rojnica, F.

    2005-01-01

    The issue of prompt professional occupational dose reporting is raised when the interval between doses is short or when the radiation source suffers a technical failure. Every involved person should be able to recognised individual or group radiation exposure. Actual radiation quality of the source is to be taken into account. To optimise radiation protection of dental radiologists, dental x-ray units were subject to Quality Control measurements. Scattering radiation from the patient's dental structures was measured in order to prove the results published by S. Tabakov, but using the modern RVG dental mode and several classical diagnostic positions. We used a special head phantom (real scull + Perspex + crown glass) and common dental x-ray units of various brands and types. The radiation quality was measured using standard QA/QC equipment. We measured the radiation scattered from the phantom in the horizontal plane (at thyroid height) at 0.5 m distance from the centre of the phantom. The measurement were done for a number of standard dental x-ray procedures, but this paper presents only the scattering caused by the upper premolars. The attenuation in the facial tissue was minimal and the majority of incidental radiation passes through the open mouth of a patient directly into the room area causing occupational exposure. The results we obtained are consistent with earlier reports on patient dosimetry. Occupational exposure is much lower if a modern RVG technique is used and no radiation protection threshold is exceeded in relation to Croatian laws. Much more important is the fact that the need for protective equipment and shielding is smaller if QA warrants proper technical operation of the x-ray tube. The maintenance of dental units is essential and so is a proper training of staff using modern diagnostic techniques. The control area around the x-ray unit is to be calculated and established for every standard dental unit (this does not apply for panoramic x-rays

  11. Recovery of silver from used X-ray film using alkaline protease from ...

    African Journals Online (AJOL)

    Jane Erike-Etchie

    2016-06-29

    Jun 29, 2016 ... Silver is an important industrial metal used in several areas such as photographic and x-ray films, jewelries, silver ... field of enzyme production. It is widely used in leather industry, diagnosis process, extraction of silver, animal.

  12. Filming Femtosecond Molecular Movies with X-ray Pulses

    DEFF Research Database (Denmark)

    Kjær, Kasper Skov

    of molecular species in solution, describing the interplay between electronic and structural dynamics, as well as the role of the solvent. This will be followed by an introduction of the three X-ray techniques used in this work, and it will be shown how the application of these techniques in a laser pump / X...

  13. The study on the protection and actual condition of using the dental x-ray unit

    International Nuclear Information System (INIS)

    Kang, Eun Ju; Yoo, Beong Gyu

    2000-01-01

    This paper will present the result of research which was done with 201 places on the actual condition of using dental diagnostic radiography unit and the protection of radiography. The purpose of this paper is to comprehend the actual condition of using dental x-ray unit and to protect when they do radiation work. Moreover this paper was completed to prepare basic materials that could be helpful to reduce the exposure from radiation. This paper obtains the following result. On radiation photographing work in the dentist office, 60.3% of dental hygienists treat this job, and 19.2% of assistants, 10.8% of dentists, 5.6% of radiolotechnologists and 4.2% others performed this job. The case that radiation worker is educated about diagnostic radiography safety supervision has been shown 14.4% and uneducated case has been shown 78.1%. The result about the actual condition of using the oral diagnostic radiation per day was that a number of film which take photograph again (less than 1 exposure) was 40.3%. Normal photographing (1 ∼ 10 exposure) was 85.1% which is the highest percentage. Using the bitewing film and occlusal film was 7.0%, and 12.4% respectively. The percent that they use cephalo film and panoramic film was 16.4%, 29.8% respectively. Dental intra diagnostic radiography unit made in 1996 ∼ 2000 was 24.9% and the one made in 1991 ∼ 1995 was 19.9%, in 1986 ∼ 1990 was 19.9%, in 1985 was 9.5% according to the answer. On kVp, they use 60 kVp mostly (61.7%) and On mA, they use 10 mA with the highest percent (66.7%). On the dental extra diagnostic radiography units which are used for doing the extra oral radiography, the one made in 1996 ∼ 2000 was 13.4%, in 1991 ∼ 1995 was 9.5%, in 1985 ∼ 1990 was 2.0% according to the answer. They use 71 ∼ 80 kVp with 10.9% and 60 ∼ 75 kVp with 9.5%. They use less than 10 mA with 19.4% and 11 ∼ 15 mA with 2.5%, 16 ∼ 20 mA with 1.5%. But the case they exactly do not know how much mA they use or they do not have

  14. The study on the protection and actual condition of using the dental x-ray unit

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Eun Ju; Yoo, Beong Gyu [Wonkwang Health Science College, Iksan (Korea, Republic of)

    2000-04-15

    This paper will present the result of research which was done with 201 places on the actual condition of using dental diagnostic radiography unit and the protection of radiography. The purpose of this paper is to comprehend the actual condition of using dental x-ray unit and to protect when they do radiation work. Moreover this paper was completed to prepare basic materials that could be helpful to reduce the exposure from radiation. This paper obtains the following result. On radiation photographing work in the dentist office, 60.3% of dental hygienists treat this job, and 19.2% of assistants, 10.8% of dentists, 5.6% of radiolotechnologists and 4.2% others performed this job. The case that radiation worker is educated about diagnostic radiography safety supervision has been shown 14.4% and uneducated case has been shown 78.1%. The result about the actual condition of using the oral diagnostic radiation per day was that a number of film which take photograph again (less than 1 exposure) was 40.3%. Normal photographing (1 {approx} 10 exposure) was 85.1% which is the highest percentage. Using the bitewing film and occlusal film was 7.0%, and 12.4% respectively. The percent that they use cephalo film and panoramic film was 16.4%, 29.8% respectively. Dental intra diagnostic radiography unit made in 1996 {approx} 2000 was 24.9% and the one made in 1991 {approx} 1995 was 19.9%, in 1986 {approx} 1990 was 19.9%, in 1985 was 9.5% according to the answer. On kVp, they use 60 kVp mostly (61.7%) and On mA, they use 10 mA with the highest percent (66.7%). On the dental extra diagnostic radiography units which are used for doing the extra oral radiography, the one made in 1996 {approx} 2000 was 13.4%, in 1991 {approx} 1995 was 9.5%, in 1985 {approx} 1990 was 2.0% according to the answer. They use 71 {approx} 80 kVp with 10.9% and 60 {approx} 75 kVp with 9.5%. They use less than 10 mA with 19.4% and 11 {approx} 15 mA with 2.5%, 16 {approx} 20 mA with 1.5%. But the case they

  15. The irradiation action on human dental tissue by X-rays and electrons. A nanoindenter study

    Energy Technology Data Exchange (ETDEWEB)

    Fraenzel, Wolfgang [Halle-Wittenberg Univ., Halle (Germany). Dept. of Physics; Gerlach, Reinhard [Halle-Wittenberg Univ., Halle (Germany). Clinic of Radiation Therapy

    2009-07-01

    It is known that ionizing radiation is used in medicine for Roentgen diagnostics and for radiation therapy. The radiation interacts with matter, in particular with biological one, essentially by scattering, photoelectric effect, Compton effect and pair production. To what extent the biological material is changed thereby, depends on the type and the amount of radiation energy, on the dose and on the tissue constitution. In modern radiation therapy two different kinds of radiation are used: high energy X-rays and electron radiation. In the case of head-neck tumors the general practice is an irradiation with high energy X-rays with absorbed dose to water up to 70 Gy. Teeth destruction has been identified as a side effect during irradiation. In addition, damage to the salivary glands is often observed which leads to a decrease or even the complete loss of the salivary secretion (xerostomia). This study shows how the different energy and radiation types damage the tooth tissue. The effects of both, high X-ray energy and high energy electrons, on the mechanical properties hardness and elasticity of the human dental tissue are measured by the nanoindentation technique. We compare these results with the effect of the irradiation of low X-ray energy on the dental tissue. (orig.)

  16. The irradiation action on human dental tissue by X-rays and electrons. A nanoindenter study

    International Nuclear Information System (INIS)

    Fraenzel, Wolfgang; Gerlach, Reinhard

    2009-01-01

    It is known that ionizing radiation is used in medicine for Roentgen diagnostics and for radiation therapy. The radiation interacts with matter, in particular with biological one, essentially by scattering, photoelectric effect, Compton effect and pair production. To what extent the biological material is changed thereby, depends on the type and the amount of radiation energy, on the dose and on the tissue constitution. In modern radiation therapy two different kinds of radiation are used: high energy X-rays and electron radiation. In the case of head-neck tumors the general practice is an irradiation with high energy X-rays with absorbed dose to water up to 70 Gy. Teeth destruction has been identified as a side effect during irradiation. In addition, damage to the salivary glands is often observed which leads to a decrease or even the complete loss of the salivary secretion (xerostomia). This study shows how the different energy and radiation types damage the tooth tissue. The effects of both, high X-ray energy and high energy electrons, on the mechanical properties hardness and elasticity of the human dental tissue are measured by the nanoindentation technique. We compare these results with the effect of the irradiation of low X-ray energy on the dental tissue. (orig.)

  17. Association of brain cancer with dental x-rays and occupation in Missouri

    International Nuclear Information System (INIS)

    Neuberger, J.S.; Brownson, R.C.; Morantz, R.A.; Chin, T.D.

    1991-01-01

    This investigation of a brain cancer cluster in Missouri used two approaches to investigate associations with potential risk factors. In a case-control study in a rural town, we interviewed surrogates of cases and controls about potential risk factors. We found a statistically significant positive association of brain cancer with reported exposure to dental x-rays. Occupation was not associated with the cluster in the rural town. In a standardized proportional mortality study for the state of Missouri, we calculated the observed and expected proportion of brain cancers by occupation and industry in Missouri decedents. We found that motor vehicle manufacturers, beauty shop workers, managers and administrators, elementary school teachers, and hairdressers and cosmetologists had significantly elevated proportions of brain cancer. Brain tumors are inconsistently associated with occupation in the literature. Further study of brain cancer etiology with respect to dental x-ray exposures seems warranted

  18. X-ray fluorescence analysis of thin films at glancing-incident and -takeoff angles

    International Nuclear Information System (INIS)

    Tsuji, K.; Sato, S.; Hirokawa, K.

    1995-01-01

    We have developed a new analytical method, Glancing-Incidence and -Takeoff X-Ray Fluorescence (GIT-XRF) method for the first time. Here, we present an idea for a thin-film analysis and a surface analysis by the GIT-XRF method. In this method, the dependence of the fluorescent x-ray intensity on takeoff angle is measured at various incident angles of the primary x-ray. Compared with a total reflection x-ray fluorescence method, the GIT-XRF method allows a detailed thin-film analysis, because the thin film is cross-checked by many experimental curves. Moreover, a surface-sensitive analysis is also possible by the GIT-XRF method. (author)

  19. X-ray crystallography

    Science.gov (United States)

    2001-01-01

    X-rays diffracted from a well-ordered protein crystal create sharp patterns of scattered light on film. A computer can use these patterns to generate a model of a protein molecule. To analyze the selected crystal, an X-ray crystallographer shines X-rays through the crystal. Unlike a single dental X-ray, which produces a shadow image of a tooth, these X-rays have to be taken many times from different angles to produce a pattern from the scattered light, a map of the intensity of the X-rays after they diffract through the crystal. The X-rays bounce off the electron clouds that form the outer structure of each atom. A flawed crystal will yield a blurry pattern; a well-ordered protein crystal yields a series of sharp diffraction patterns. From these patterns, researchers build an electron density map. With powerful computers and a lot of calculations, scientists can use the electron density patterns to determine the structure of the protein and make a computer-generated model of the structure. The models let researchers improve their understanding of how the protein functions. They also allow scientists to look for receptor sites and active areas that control a protein's function and role in the progress of diseases. From there, pharmaceutical researchers can design molecules that fit the active site, much like a key and lock, so that the protein is locked without affecting the rest of the body. This is called structure-based drug design.

  20. In situ X-ray studies of film cathodes for solid oxide fuel cells

    International Nuclear Information System (INIS)

    Fuoss, Paul; Chang, Kee-Chul; You, Hoydoo

    2013-01-01

    Highlights: •Synchrotron X-rays are used to study in operando the structural and chemical changes of LSM and LSCF film cathodes during half-cell operations. •A-site and B-site cations actively segregate or desegregate on the changes of temperature, pO 2 , and electrochemical potential. •Chemical lattice expansions show that oxygen-cathode interface is the primary source of rate-limiting processes. •The surface and subsurface of the LSM and LSCF films have different oxidation-states due to vacancy concentration changes. •Liquid-phase infiltration and coarsening processes of cathode materials into porous YSZ electrolyte backbone were monitored by USAXS. -- Abstract: Synchrotron-based X-ray techniques have been used to study in situ the structural and chemical changes of film cathodes during half-cell operations. The X-ray techniques used include X-ray reflectivity (XR), total-reflection X-ray fluorescence (TXRF), high-resolution diffraction (HRD), ultra-small angle X-ray scattering (USAXS). The epitaxial thin film model cathodes for XR, TXRF, and HRD measurements are made by pulse laser deposition and porous film cathodes for USAX measurements are made by screen printing technique. The experimental results reviewed here include A-site and B-site segregations, lattice expansion, oxidation-state changes during cell operations and liquid-phase infiltration and coarsening of cathode to electrolyte backbone

  1. Parallelized Bayesian inversion for three-dimensional dental X-ray imaging.

    Science.gov (United States)

    Kolehmainen, Ville; Vanne, Antti; Siltanen, Samuli; Järvenpää, Seppo; Kaipio, Jari P; Lassas, Matti; Kalke, Martti

    2006-02-01

    Diagnostic and operational tasks based on dental radiology often require three-dimensional (3-D) information that is not available in a single X-ray projection image. Comprehensive 3-D information about tissues can be obtained by computerized tomography (CT) imaging. However, in dental imaging a conventional CT scan may not be available or practical because of high radiation dose, low-resolution or the cost of the CT scanner equipment. In this paper, we consider a novel type of 3-D imaging modality for dental radiology. We consider situations in which projection images of the teeth are taken from a few sparsely distributed projection directions using the dentist's regular (digital) X-ray equipment and the 3-D X-ray attenuation function is reconstructed. A complication in these experiments is that the reconstruction of the 3-D structure based on a few projection images becomes an ill-posed inverse problem. Bayesian inversion is a well suited framework for reconstruction from such incomplete data. In Bayesian inversion, the ill-posed reconstruction problem is formulated in a well-posed probabilistic form in which a priori information is used to compensate for the incomplete information of the projection data. In this paper we propose a Bayesian method for 3-D reconstruction in dental radiology. The method is partially based on Kolehmainen et al. 2003. The prior model for dental structures consist of a weighted l1 and total variation (TV)-prior together with the positivity prior. The inverse problem is stated as finding the maximum a posteriori (MAP) estimate. To make the 3-D reconstruction computationally feasible, a parallelized version of an optimization algorithm is implemented for a Beowulf cluster computer. The method is tested with projection data from dental specimens and patient data. Tomosynthetic reconstructions are given as reference for the proposed method.

  2. X-ray magnetic circular dichroism and hard X-ray photoelectron spectroscopy of tetragonal Mn72Ge28 epitaxial thin film

    Science.gov (United States)

    Kim, Jinhyeok; Mizuguchi, Masaki; Inami, Nobuhito; Ueno, Tetsuro; Ueda, Shigenori; Takanashi, Koki

    2018-04-01

    An epitaxially grown Mn72Ge28 film with a tetragonal crystal structure was fabricated. It was clarified that the film had a perpendicular magnetization and a high perpendicular magnetic anisotropy energy of 14.3 Merg/cm3. The electronic structure was investigated by X-ray magnetic circular dichroism and hard X-ray photoelectron spectroscopy. The obtained X-ray magnetic circular dichroism spectrum revealed that the Mn orbital magnetic moment governed the magnetocrystalline anisotropy of the Mn72Ge28 film. A doublet structure was observed for the Mn 2p3/2 peak of hard X-ray photoelectron spectrum, indicating the spin exchange interaction between the 2p core-hole and 3d valence electrons.

  3. Abdominal x-ray

    Science.gov (United States)

    Abdominal film; X-ray - abdomen; Flat plate; KUB x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  4. Measurements of reciprocity law failure in green-sensitive X-ray films.

    Science.gov (United States)

    Arnold, B A; Eisenberg, H; Bjärngard, B E

    1978-02-01

    Reciprocity law failure was measured for four brands of medical x-ray films exposed with intensifying screens. Three of the films are green light-sensitized for use in combination with green light-emitting rare-earth screens. These films showed larger reciprocity failure effects than one conventional blue-sensitive film, Dupont Cronex-2. Development conditions had a small effect on reciprocity failure. As part of the investigation, a detector was constructed with a response that accurately monitors the light emission from the double screen-cassette combination over a wide range of x-ray photon energies.

  5. Application of digital tomosynthesis (DTS) of optimal deblurring filters for dental X-ray imaging

    International Nuclear Information System (INIS)

    Oh, J. E.; Cho, H. S.; Kim, D. S.; Choi, S. I.; Je, U. K.

    2012-01-01

    Digital tomosynthesis (DTS) is a limited-angle tomographic technique that provides some of the tomographic benefits of computed tomography (CT) but at reduced dose and cost. Thus, the potential for application of DTS to dental X-ray imaging seems promising. As a continuation of our dental radiography R and D, we developed an effective DTS reconstruction algorithm and implemented it in conjunction with a commercial dental CT system for potential use in dental implant placement. The reconstruction algorithm employed a backprojection filtering (BPF) method based upon optimal deblurring filters to suppress effectively both the blur artifacts originating from the out-focus planes and the high-frequency noise. To verify the usefulness of the reconstruction algorithm, we performed systematic simulation works and evaluated the image characteristics. We also performed experimental works in which DTS images of enhanced anatomical resolution were successfully obtained by using the algorithm and were promising to our ongoing applications to dental X-ray imaging. In this paper, our approach to the development of the DTS reconstruction algorithm and the results are described in detail.

  6. [Standards and guidelines of radiation protection and safety in dental X-ray examinations].

    Science.gov (United States)

    Guo, X L; Li, G; Cheng, Y; Yu, Q; Wang, H; Zhang, Z Y

    2017-12-09

    With the rapid development of imaging technology, the application of dental imaging in diagnosis, treatment planning, intraoperative surgical navigation, monitoring of treatment or lesion development and assessment of treatment outcomes is playing an essential role in oral healthcare. The increased total number of dental X-ray examinations is accompanied by a relatively significant increase in collective dose to patients as well as to dental healthcare workers, which is harmful to human bodies to a certain degree. Some radiation protection standards and guidelines in dental radiology have been published in European countries, US, Canada and Australia, etc. Adherence to these standards and guidelines helps to achieve images with diagnostic quality and avoid unnecessary and repeated exposures. However, no radiation protection standard or guideline with regard to dental X-ray examinations has been put in force so far in mainland China. Therefore, a literature review on available radiation protection standards and guidelines was conducted to provide reference to the development of radiation protection standards or guidelines in mainland China.

  7. Density determination of langmuir-blodgett monolayer films using x-ray reflectivity technique

    International Nuclear Information System (INIS)

    Damar Yoga Kusuma

    2015-01-01

    Monolayer deposition by Langmuir-Blodgett technique produces monolayer films that are uniform with controllable thickness down to nanometer scale. To evaluate the quality of the monolayer deposition, X-ray reflectivity technique are employed to monitor the monolayers density. Langmuir-Blodgett monolayer with good coverage and uniformity results in film density close to its macroscopic film counterpart whereas films with presence of air gaps shows lower density compared to its macroscopic film counterpart. (author)

  8. Spectral and spatial characteristics of x-ray film/screen combinations up to x-ray energy of 3 MeV

    International Nuclear Information System (INIS)

    Ginzburg, A.; Carmel, Y.; Segal, Y.; Notea, A.

    1986-01-01

    The present study is directed towards quantifying some of the parameters which define the quality of the image obtained on x-ray sensitive films and its usual accompanying intensifying screens. Both industrial (Agfa-Geveart D2,D4,D7) and medical (Kodak XAR-5) films with a variety of screens such as metallic (lead) and fluorescent (calcium tungstate, rare earth) were compared. A variety of sources were employed (radioactive, linear accelerators, flash) in order to cover the average x-ray energy spectrum from 100KeV to 3000KeV. This energy spectrum is of interest for non destructive testing, terminal ballistics and for medical purposes. The results indicate that the sensitivity of industrial x-ray films decreases with energy in the range of 100KeV to 1MeV, levels off and increases again with increasing energy. A 2.75MeV Na 24 radioactive source was used to achieve accurate calibration at the high end of the spectrum. Also, the noise level of x-ray industrial films versus film density was found to peak at a density of D=1.4. The line spread function (LSF) - or resolution - of both industrial and medical film/screen combinations were derived from the optical density of a step wedge response on the film. The noise level of medical films is twice as high compared to industrial films and their LSF is 4 to 8 times larger at x-ray energies of 3MeV. Using Pb screens in contact with common industrial x-ray films yields amplification of 2 (compared to a bare film)

  9. Thin film growth studies using time-resolved x-ray scattering

    Science.gov (United States)

    Kowarik, Stefan

    2017-02-01

    Thin-film growth is important for novel functional materials and new generations of devices. The non-equilibrium growth physics involved is very challenging, because the energy landscape for atomic scale processes is determined by many parameters, such as the diffusion and Ehrlich-Schwoebel barriers. We review the in situ real-time techniques of x-ray diffraction (XRD), x-ray growth oscillations and diffuse x-ray scattering (GISAXS) for the determination of structure and morphology on length scales from Å to µm. We give examples of time resolved growth experiments mainly from molecular thin film growth, but also highlight growth of inorganic materials using molecular beam epitaxy (MBE) and electrochemical deposition from liquids. We discuss how scaling parameters of rate equation models and fundamental energy barriers in kinetic Monte Carlo methods can be determined from fits of the real-time x-ray data.

  10. Evaluation of the shielding of dental X-rays units; Evaluacion del blindaje de unidades de rayos X dentales

    Energy Technology Data Exchange (ETDEWEB)

    Medrano, E.; Vega C, H. R.; Letechipia de L, C.; Hernandez D, V. M.; Salas L, M. A., E-mail: edumeco@yahoo.com.mx [Universidad Autonoma de Zacatecas, Apdo. Postal 336, 98000 Zacatecas (Mexico)

    2014-08-15

    The capacity of the walls of the dental radio-diagnostic rooms has been determined, to diminish the dose levels during the use of the X-rays equipment s. The study was carried out in the Dentistry Academic Unit of the campus Siglo X XI of the Universidad Autonoma de Zacatecas. The X-rays equipment s are a learning tool for the dentistry students and they are also used for offering health services to the population; for this reason is important to verify that the dose levels outside of the room walls are safe. During the evaluation process were used conservative approaches without prejudice of the thickness necessary in benefit of the radiological protection. Of the evaluation was found that all the walls satisfy their function thoroughly like barriers against the X-rays. (Author)

  11. A new attempt of measurement film thickness by x-ray diffractometry

    International Nuclear Information System (INIS)

    Kosaka, Masao; Kobayashi, Hideo

    1987-01-01

    In order to make film thickness measurements independent from the property or the structure of the film materials or the substrate, it is needed to adopt instead of directly utilizing the X-ray diffraction intensity, or attenuation information obtained from the substrate or film material, other new methods for measurement. Among the information obtained by X-ray diffraction, if intensity is excluded, others are F.W.H.M. and diffraction angle, only. If it is possible to investigate the film thickness dependency of the diffraction angle, it should be possible to measure the film thickness by diffraction angle. However, since diffraction angle has no film thickness dependency, it cannot be used directly for measurement. However, if we consider the principle of the X-ray diffractometer method, although it may be very slight, the substrate will be eccentric from the revolving center of the goniometer on account of the thickness of the film. If eccentricity occurs, this will cause changes in the diffraction angle. If we set the radius of the goniometer as R, diffraction angle θ, and the eccentricity from the revolving center of the specimen surface X, the deflection angle Δ2θ of 2θ may be expressed by Δ2θ = -2X · COSθ/R Thus, if X is caused by the film thickness, and by measuring the Δ2θ, it will be possible to measure the film thickness. As a result of the experiment, it was found that X-ray diffraction method can be used for the measurement of the film thickness of a few microns or above by utilizing the eccentricity caused by the film thickness. Especially it has the advantage of being able to measure thick films that X-rays will not penetrate, without being influenced by the chemical structure of the film or the substrates. (author)

  12. Asbestos, dental x-rays, tobacco, and alcohol in the epidemiology of laryngeal cancer

    International Nuclear Information System (INIS)

    Hinds, M.W.; Thomas, D.B.; O'Reilly, H.P.

    1979-01-01

    A case-control study of 47 laryngeal cancers in males of three counties of Washington State was conducted. Personal interview was used to obtain information on smoking, alcohol use, exposure to asbestos, and other substances, and x-rays of the head and neck area. Smoking and alcohol consumption were found to increase risk of laryngeal cancer independently, with a clear dose-response relationship. Neither asbestos exposure nor exposure to other substances was found to significantly increase the risk of laryngeal cancer, although the relative risk with asbestos exposure was 1.75. Lifetime history of exposure to dental x-rays on five or more occasions was associated with significantly increased risk of laryngeal cancer among heavy smokers but not among light smokers. The importance of tobacco and alcohol in the epidemiology of laryngeal cancer was re-affirmed, the importance of asbestos exposure was brought into question, and a possible relationship of laryngeal cancer with exposure to dental x-rays among heavy smokers was demonstrated

  13. Absorption spectra response of XRQA radiochromic film to x-ray radiation

    International Nuclear Information System (INIS)

    Alnawaf, Hani; Cheung, Tsang; Butson, Martin J.; Yu, Peter K.N.

    2010-01-01

    Gafchromic XRQA, radiochromic film is a high sensitivity auto developing x-ray analysis films designed and available for kilovoltage x-ray, dose and QA assessment applications. The film is designed for reflective analysis with a yellow transparent top filter and white opaque backing materials. This allows the film to be visually inspected for colour changes with a higher level of contrast than clear coated radiochromic films such as Gafchromic EBT version 1. The spectral absorption properties in the visible wavelengths have been investigated and results show two main peaks in absorption located at 636 nm and 585 nm. These peaks are located in the same position as EBT Gafchromic film highlighting a similar chemical monomer/polymer for radiation sensitivity. A much higher sensitivity however is found at kilovoltage energies with an average 1.55 OD units per 20 cGy irradiation variation measured at 636 nm using 150 kVp x-rays. This is compared to approximately 0.12 OD units per 20 cGy measured at 636 nm for EBT film at 6 MV x-ray energy. That is, the XRQA film is more than 10 times more sensitive than EBT1 film. The visual colour change is enhanced by the yellow polyester coating. However this does not affect the absorption spectra properties in the red region of analysis which is the main area for use using desktop scanners in reflection mode.

  14. Radiation exposure to foetus and breasts from dental X-ray examinations: effect of lead shields.

    Science.gov (United States)

    Kelaranta, Anna; Ekholm, Marja; Toroi, Paula; Kortesniemi, Mika

    2016-01-01

    Dental radiography may involve situations where the patient is known to be pregnant or the pregnancy is noticed after the X-ray procedure. In such cases, the radiation dose to the foetus, though low, needs to be estimated. Uniform and widely used guidance on dental X-ray procedures during pregnancy are presently lacking, the usefulness of lead shields is unclear and practices vary. Upper estimates of radiation doses to the foetus and breasts of the pregnant patient were estimated with an anthropomorphic female phantom in intraoral, panoramic, cephalometric and CBCT dental modalities with and without lead shields. The upper estimates of foetal doses varied from 0.009 to 6.9 μGy, and doses at the breast level varied from 0.602 to 75.4 μGy. With lead shields, the foetal doses varied from 0.005 to 2.1 μGy, and breast doses varied from 0.002 to 10.4 μGy. The foetal dose levels without lead shielding were dental radiographic examination.

  15. Radiochromic film measurement of spatial uniformity for a laser generated x-ray environment

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, J. H.; Newlander, C. D.; Horton, R.; Fournier, K. B.; Emig, J.; Patterson, R.; Davis, J. F.; Seiler, S.; Jenkins, P. P.

    2012-10-01

    n existing x-ray source application (XRSA) test cassette was modified to hold multiple x-ray filter materials followed by two radiochromic film types (FWT-60 and HD-810 Gafchromic® film) to qualitatively characterize the spectral-spatial uniformity over the XRSA sample field of view. Multiple sets of film were examined and nominal set was determined. These initial, qualitative measurements suggest a low-energy regime (E < 3 keV) spatial anisotropy and spatial isotropy at higher energies (E > 3 keV).

  16. Structure and x-ray density of electrochemically deposited rhenium films

    International Nuclear Information System (INIS)

    Petrovich, V.A.; Fedenkov, A.L.; Shepurev, S.Yu.

    1988-01-01

    The electrodeposition of rhenium was carried out at a constant cathode-current density and room temperature. The backing was grade KEF-0.02 single-crystal silicon. The absorption coefficient μ of the film was determined for the K α radiation of the copper line. The investigation enabled us to conclude that electrochemically deposited rhenium films can be used as a material for the masking coatings of x-ray patterns, since the absorption coefficients of the x-ray radiation of the resultant films are superior to the similar parameters of traditionally employed materials, and surpass these materials in terms of corrosion resistance and simplicity of production

  17. Minimizing hospital losses in x-ray films using design of experiments

    International Nuclear Information System (INIS)

    Aljohani, M.S.; Moreb, A.A.; Naser Al Qasabi; Bandar Sobahi

    2004-01-01

    Exposure of patients to excessive radiation increases an unnecessary risk of cancer. An X-ray film is considered a reject and is to be repeated if the contrast between the image (picture) of the organ and the films background is low. Applying a two stages approach of Design of Experiments (DOE), this paper considers the factors affecting the contrast of the X-ray film, sorts out the most influential factors and identifies the optimum settings for each factor. Furthermore, the contribution of each factor on the optimal contrast is statistically identified. (Author)

  18. The origin of stress in sputter-deposited tungsten films for x-ray masks

    International Nuclear Information System (INIS)

    Itoh, M.; Hori, M.; Nadahara, S.

    1991-01-01

    The mechanism for the cause of stress in a sputter-deposited tungsten (W) film has been clarified. The tensile stress of the film was calculated using the interatomic forces acting on the grain boundary. The average distance of the grain boundary gaps was determined from the measured film density assuming the film had homogeneous size rectangular grains. The calculated and measured stress values were in good agreement in the high working gas pressure region. The difference between these values in the low working gas pressure region has been able to be explained by the compressive stress due to the peening effect of Ar. The low stress in the high pressure region was obtained by large opened grain boundaries which produced low film density. A low film density causes a low x-ray stopping power. The film deposited in the low pressure region is suitable as an x-ray absorber because of its high film density

  19. An Audit Of Rejected Repeated X-ray Films As A Quality Assurance ...

    African Journals Online (AJOL)

    To find out the causes, number, percentage and sizes of rejected radiographic filmswith a view of adopting measures that will reduce the rate and number of rejected films. Radiology Department of a University Teaching Hospital. Over a two-year period (1 April 2002 to 31 March 2004), the total number of x-ray films utilized ...

  20. Effect of dental metal in 10 MV X-ray beam therapy

    International Nuclear Information System (INIS)

    Mimura, Seiichi; Mikami, Yasutaka; Inamura, Keiji; Tahara, Seiji; Nagaya, Isao; Egusa, Tomomi; Nakagiri, Yoshitada; Sugita, Katsuhiko.

    1991-01-01

    We have often encountered patients with dental metal when employing the 10 MV X-ray beam therapy for head and neck tumors, and felt it important to investigate the effect of dental metal in relation to dose distribution. The absorbed dose rose abruptly in the vicinity of the metal reaching an interface value equal to 150% of the dose within the acrylic phantom. These results showed that an overdose occurred about 5 mm from the metal. We also learned that the overdose can be avoided by using a 5-mm thick tissue equivalent material. Six patients with dental metal were treated after first covering their metal with a 5-mm thick mouthpiece. No radiation stomatitis caused by the metal was observed in any of these cases. (author)

  1. Application of X-rays to dental age estimation in medico-legal practice

    Directory of Open Access Journals (Sweden)

    Dorota Lorkiewicz-Muszyńska

    2015-05-01

    Full Text Available Aim of the study: The paper addresses the use of dental age assessment methods based on radiographs in medico-legal practice. Different cases of practical application of the methods are presented including identification of human remains, dental age assessment in a living person and one archaeological case. Material and methods : The study material consisted of cases involving dental age assessment performed in the Department of Forensic Medicine, Poznan University of Medical Sciences in Poznan. Depending on the preliminary assessment of age, the Liversidge or the Kvaal et al. methods were applied. Dental age was estimated on the basis of available pantomograms. In the case of the living person, it was a radiograph supplied for expert evaluation. In the other cases, dental computed tomography was performed. Results : Dental age was successfully estimated in all of the cases. Various methods based on the analysis of X-ray images were applied. Dental age was shown to be correlated with skeletal age. Conclusions : The methods based on radiographs were demonstrated to be useful, and the results they yield are fully correlated with results of anthropological analyses.

  2. Discussion of ALTERNATIVE systems for industrial radiography using X-ray films

    International Nuclear Information System (INIS)

    Vaessen B.; Perdieus, P.; Proegler, H.

    1995-01-01

    Industrial radiography using X-ray films is an established method of NDE. In the last few years, ''novel developments'' have been put on the market as ''alternatives'' to conventional radiography, as e.g. fluorescent screen/film systems, cost-saving films, wide-latitude films, and storage phosphor films. AGFA as a market leader in the sector of X-ray films for industrial radiography has been testing these alternatives, taking into account image quality, sensitivity, handling in terms of portability, reliability, and the essential functions for NDE: (1) Detection of X-radiation; (2) conversion to optical image; (3) evaluation and validation; (4) documentation and archivation. The advantages and drawbacks, the information transfer capabilities, and the performance from the applications point of view are discussed primarily for fluorescent screen/film systems and storage phophor systems. (orig./MM) [de

  3. X-ray diffractometry of 10 nm thick YBa2Cu3O7-x films

    International Nuclear Information System (INIS)

    Drozdov, Yu.N.; Moldavskaya, L.D.; Parafin, A.E.

    1998-01-01

    We report on some specific features of the X-ray diffraction spectra for ultrathin c-axis-oriented YBCO films. The films were prepared by laser deposition on LaAlO 3 substrates. A DRON-4 powder diffractometer was used to analyze a structure and to measure thickness of the films. We find that this conventional technique can detect the YBCO films as thin as 5 nm. The X-ray interference fringes in the vicinity of the (005) YBCO reflections for the films from 10 to 20 nm thick were clearly visible. The oscillation period of the fringes depends on the thickness of the film and the intensity modulation yields some structural information. The I(-1)/I(+1) fringes intensity ratio was found to be sensitive to the type of atomic layer at the top and bottom of YBCO film [ru

  4. Correlating properties and microstructure of YBCO thin films by magnetic X-ray microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ruoss, Stephen; Stahl, Claudia; Weigand, Markus; Schuetz, Gisela [Max-Planck-Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart (Germany); Zahn, Patrick; Bayer, Jonas [Max-Planck-Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart (Germany); Research Institute for Innovative Surfaces, FINO, Aalen University, Beethovenstrasse 1, 73430 Aalen (Germany); Albrecht, Joachim [Research Institute for Innovative Surfaces, FINO, Aalen University, Beethovenstrasse 1, 73430 Aalen (Germany)

    2016-07-01

    The magnetic flux distribution in high-temperature superconductors namely YBCO has been observed using a novel high-resolution technique based on the X-ray magnetic circular dichroism (XMCD). Therefore, a CoFeB layer is deposited on the superconductor which exhibits a strong XMCD-effect. X-ray absorption measurements with circular polarized radiation allows the analysis of the magnetic flux distribution in the superconductor via the soft-magnetic sensor layer [3,4]. In the total electron yield (TEY) mode of the scanning X-ray microscope (SXM) the surface structure and the magnetic domains can be imaged at the same time. Having obtained such high resolution images, the correlation of magnetic flux penetration and defect structure of YBCO thin films can be analyzed. The measurements have been performed at the scanning X-ray microscope MAXYMUS at Bessy II, HZB Berlin.

  5. Measurement of thickness of thin films by the X-ray diffraction method

    International Nuclear Information System (INIS)

    Srinivasan, C.; Balasingh, C.; Singh, A.K.

    1979-07-01

    X-ray diffraction method can be used to measure the thickness of thin films (coatings). The principle and the experimental details of the x-ray diffraction methods are described. The intensities of the diffracted beams are derived assuming a random orientation of the crystallites in the diffracting medium. Consequently, the expressions are not valid when the sample has preferred orientation. To check the performance of the method, thicknesses of nickel deposits on mild steel plates were determined by the x-ray diffraction method and the results compared with those obtained by the weighing method and metallographic examination. The weighing method which gives an accuracy of +- 0.1 micron is taken as the standard. The x-ray diffraction methods and the metallographic examinations give values within +- 1 micron of the value obtained by the weighing method. (author)

  6. X-ray specular reflection and fluorescence study of nano-films

    International Nuclear Information System (INIS)

    Zheludeva, S.; Novikova, N.

    2001-01-01

    The techniques that combine the advantages of high-resolution structure sensitive x-ray methods with spectroscopic selectivity of data obtained are shown to be extremely promising for characterization of organic and inorganic nano films and nano structures. Fluorescence yield angular dependences exited by complicated evanescent wave / x-ray standing wave pattern at total reflection and glancing incidence can be used to detect structure position of different ions in organic systems and alien interfacial layers in inorganic multilayers;, to get information about interdiffusion at the interfaces of Langmuir- Blodgett (L-B) films and artificial inorganic - x-ray mirrors; to study ion permeation through L-B nano structures - models of biomembrans; to obtain nano - film thickness and density; to get precisely the parameters of small d-space multilayer mirrors, ets

  7. X-ray absorption fine structure (XAFS) studies of cobalt silicide thin films

    International Nuclear Information System (INIS)

    Naftel, S.J.; Coulthard, I.; Hu, Y.; Sham, T.K.; Zinke-Allmang, M.

    1998-01-01

    Cobalt silicide thin films, prepared on Si(100) wafers, have been studied by X-ray absorption near edge structures (XANES) at the Si K-, L 2,3 - and Co K-edges utilizing both total electron (TEY) and fluorescence yield (FLY) detection as well as extended X-ray absorption fine structure (EXAFS) at the Co K-edge. Samples made using DC sputter deposition on clean Si surfaces and MBE were studied along with a bulk CoSi 2 sample. XANES and EXAFS provide information about the electronic structure and morphology of the films. It was found that the films studied have essentially the same structure as bulk CoSi 2 . Both the spectroscopy and materials characterization aspects of XAFS (X-ray absorption fine structures) are discussed

  8. Development and evaluation of gallium nitride-based thin films for x-ray dosimetry

    International Nuclear Information System (INIS)

    Hofstetter, Markus; Thalhammer, Stefan; Howgate, John; Sharp, Ian D; Stutzmann, Martin

    2011-01-01

    X-ray radiation plays an important role in medical procedures ranging from diagnostics to therapeutics. Due to the harm such ionizing radiation can cause, it has become common practice to closely monitor the dosages received by patients. To this end, precise online dosimeters have been developed with the dual objectives of monitoring radiation in the region of interest and improving therapeutic methods. In this work, we evaluate GaN thin film high electron mobility heterostructures with sub-mm 2 detection areas as x-ray radiation detectors. Devices were tested using 40-300 kV Bremsstrahlung x-ray sources. We find that the photoconductive device response exhibits a large gain, is almost independent of the angle of irradiation, and is constant to within 2% of the signal throughout this medical diagnostic x-ray range, indicating that these sensors do not require recalibration for geometry or energy. Furthermore, the devices show a high sensitivity to x-ray intensity and can measure in the air kerma rate (free-in-air) range of 1 μGy s -1 to 10 mGy s -1 with a signal stability of ±1% and a linear total dose response over time. Medical conditions were simulated by measurements of device responses to irradiation through human torso phantoms. Direct x-ray imaging is demonstrated using the index finger and wrist sections of a human phantom. The results presented here indicate that GaN-based thin film devices exhibit a wide range of properties, which make them promising candidates for dosimetry applications. In addition, with potential detection volumes smaller than 10 -6 cm 3 , they are well suited for high-resolution x-ray imaging. Moreover, with additional engineering steps, these devices can be adapted to potentially provide both in vivo biosensing and x-ray dosimetry.

  9. Hygiene implications associated with x-ray exposures to dental patients

    International Nuclear Information System (INIS)

    McKlveen, J.W.

    1980-01-01

    An elastic mask worn by patients, then a skeleton encased in plastic, was instrumented with LiF thermoluminescent dosimeters to quantify radiation exposures delivered from full-face diagnostic dental x-rays. Locations of interest included skin surface, eyes, upper and lower teeth and thyroid. Exposures in the 100 mR range were common and a maximum of over 6000 mR was measured in the teeth region during a full-face examination with a periapical unit. In general, exposures received from periapical equipment were several times those obtained from panoramic devices

  10. Radiation exposure of the UK population from medical and dental x-ray examinations

    International Nuclear Information System (INIS)

    Hart, D.; Wall, B.F.

    2002-03-01

    Knowledge of recent trends in the radiation doses from x-ray examinations and their distribution for the UK population provides useful guidance on where best to concentrate efforts on patient dose reduction in order to optimise the protection of the population in a cost-effective manner. In this report, the results of a recent survey of the frequency of medical and dental x-ray examinations in the UK and contemporary data on the radiation doses typically received by patients, are used to assess trends in the extent and the pattern of the population exposure. Individual patient doses, expressed in terms of the effective dose, range from a few microsieverts for simple radiographic examinations of the teeth, limbs or chest to tens of millisieverts for prolonged fluoroscopic procedures or some computed tomography (CT) examinations. A total of about 41.5 million medical and dental x-ray examinations are now conducted each year in the UK (0.70 examination per head of population) resulting in an annual per caput effective dose of 330 μSv. This is not significantly different from the previous rough estimate of 350 μSv for 1991. However, over the last ten years CT has more than doubled its contribution and is now responsible for 40% of the total dose to the population from medical x-rays. In contrast, the contribution from conventional radiographic and fluoroscopic examinations has nearly halved to about 44%. Interventional and angiographic procedures together contribute the remaining 16%. The annual per caput dose of 330 μSv is low in comparison with other countries having similarly developed systems of health care. This is due to both a lower frequency of x-ray examinations per head of population and generally lower doses in the UK than in other developed countries. However, the much increased contributions of CT, angiography and interventional procedures to the UK population dose indicate an urgent need to develop radiation protection and optimisation activities for

  11. Problems with film processing in medical X-ray imaging in Lithuania

    International Nuclear Information System (INIS)

    Sniureviciute, M.; Adliene, D.

    2005-01-01

    Optimisation in X-ray imaging in order to reduce patient doses during diagnostic X-ray examinations is a complex process given the high level of image quality required. When quality systems are implemented as a basis for optimisation, attention should be paid to the qualifications of the staff and quality control of the equipment and of the X-ray imaging procedures, as well as to the methods used to evaluate the quality of these procedures. Until recently, quality control procedures at health care institutions in Lithuania were limited to the testing of X-ray units. Since film processing is one of the most important factors influencing patient doses and image quality during X-ray examinations, in 2003 the Kaunas department of the Radiation Protection Centre organised inspections of film processing laboratories in 11 health care institutions - hospitals and outpatient departments - in the Kaunas region. Problems of non-compliance with requirements identified during these inspections are discussed in this paper. Most of the health care institutions inspected already had quality assurance programmes. However, the implementation of these programmes was sometimes erratic because of the insufficient attention paid to the film developing processes. The worst situation was found in 4 institutions where the films were developed manually. Only 3 of the 11 departments inspected had sensitometers and densitometers for quality control of the processing. In many cases there was no control of chemicals, film sensitivity and density, or else control was irregular. In only a few departments were the effects of repeated controls investigated and discussed. Despite the current problems occurring in medical X-ray diagnostic departments in Lithuania, the situation is rapidly improving. New equipment is being installed, new devices for quality control are being used and, last but not least, the view of hospital administrators, radiologists and laboratory workers towards quality

  12. Development of a concept for radiation patients exposure assessment during dental X-ray examinations and statistical data acquisition for the determination of a diagnostic reference value

    International Nuclear Information System (INIS)

    Kueppers, C.; Sering, M.; Poppe, B.; Poplawski, A.; Looe, H.K.; Beyer, D.; Pfaffenberger, A.; Chofor, N.; Eenboom, F.

    2012-01-01

    The research project on the development a concept for radiation patients exposure assessment during dental X-ray examinations and statistical data acquisition for the determination of a diagnostic reference value includes the following issues: Fundamental facts: dental X-ray examination techniques, dose relevant factors and characteristics during X-ray examinations, radiation exposed organs during dental X-ray examinations, dose assessment based on phantoms. Materials and methodologies of the project: TLD measurements using the phantom, calculation of the effective dose during dental X-ray examinations, properties and settings of the reference facilities for the determination of radiation exposure, selection of dental offices, dosimetric measurements, data acquisition and statistical evaluation. Results of dosimetric examinations: results of dosimetric measurements at reference facilities, results of dosimetric measurements in dental offices. Discussion of the concept for the determination of the radiation exposure during dental X-ray examinations.

  13. Low-energy x-ray response of photographic films. Part I. Mathematical models

    International Nuclear Information System (INIS)

    Henke, B.L.; Kwok, S.L.; Uejio, J.Y.; Yamada, H.T.; Young, G.C.

    1984-01-01

    Relatively simple mathematical models are developed for optical density as a function of the x-ray intensity, its angle of incidence and photon energy in the 100 to 10,000 eV region for monolayer and emulsion types of photographic films. Semi-empirical relations have been applied to characterize a monolayer film, Kodak 101-07, and an emulsion type film, Kodak RAR 2497, which fit calibration data at nine photon energies well within typical experimental error

  14. Low-energy x-ray response of photographic films. I. Mathematical models

    International Nuclear Information System (INIS)

    Henke, B.L.; Kwok, S.L.; Uejio, J.Y.; Yamada, H.T.; Young, G.C.

    1984-01-01

    Relatively simple mathematical models are developed to determine the optical density as a function of the x-ray intensity, its angle of incidence, and its photon energy in the 100--10,000-eV region for monolayer and emulsion types of photographic films. Semiempirical relations are applied to characterize a monolayer film (Kodak 101-07) and an emilsion-type film (Kodak RAR 2497); these relations fit calibration data at nine photon energies well within typical experimental error

  15. The dose received by patients during dental X-ray examination and the technical condition of radiological equipment.

    Science.gov (United States)

    Bekas, Marcin; Pachocki, Krzysztof A

    2013-01-01

    Implementation of X-ray dental examination is associated with the patients exposure to ionizing radation. The size of the exposure depends on the type of medical procedure, the technical condition of the X-ray unit and selected exposure conditions. The aim of this study was to determine the dose received by patients during dental X-ray examination and the assessment of the technical condition of medical equipment, The study included a total number of 79 dental X-ray units located in the region of Mazovia. The test methods for the assessment of the technical condition of dental X-ray units and measurement of radiation dose received by patients were based on the procedures elaborated in the Department of Radiation Hygiene and Radiobiology in the National Institute of Public Health - National Institute of Hygiene (Warszawa, Poland) accredited for the certification of compliance with PN-EN 17025. The research found that 69.6% fully meets the criteria set out in the Polish legislation regarding the safe use of ionizing radiation in medicine, while 30.4% did not meet some of them. A tenfold difference in the size of the dose received by patients during dental X-ray examinations was discovered. For example, during a radiography of the canine teeth of a child, the recorded entrance surface dose (ESD) ranged from 72.8 to 2430 microGy with the average value of 689.1 microGy. Cases where the dose reference level defined in Polish legislation of 5 mGy was exceeded were also found. CONCKUSIONS: It is essential to constantly monitor the situation regarding the technical condition of X-ray units which affects the size of the population's exposure to ionizing radiation as well as raising dentists' awareness about the effects of X-rays on the human body.

  16. Effects of film/foil interactions on X-ray image quality - experimental studies

    International Nuclear Information System (INIS)

    Maurer, H.J.; Goos, F.

    1985-01-01

    When assessing the quality of X-ray images, the interaction between film and foil should never be left out of account. Except for the case of green-emitting foils which require green-emitting films, films and foils are normally regarded separately, so that many variations are possible. The authors review the interaction between film and foil under practical aspects. Studies published so far have concentrated either on the amplification factor of foils or an the object imaging characteristics of certain films. Systematic studies on the interaction between film and foil have never been carried out. (orig.) [de

  17. Soft x-ray transmission measurements on thin films used for XMM CCD-filters

    Science.gov (United States)

    Stephan, K.-H.; Reppin, C.; Maier, H. J.; Frischke, D.; Fuchs, D.; Müller, P.

    1997-02-01

    We have been developing optical filters for ESA's X-ray astronomy project XMM (X-ray Multi Mirror Mission). Specific CCDs will be used as detectors in the focal plane on board the observatory (1). Since these detectors are sensitive from the X-ray to the near infrared spectral range, X-ray observations require optical filters, which combine a high transparency for photon energies in the soft X-ray region and a high opacity for ultraviolet and visible radiation as well. With respect to the mission goal in orbit three types of flight model filters are designed having different spectral transmittance functions. We report on one of these types, a so-called "thick" filter, which has been realized within the EQM (Electrical Qualification Model)-phase of the project. The filter features a cut-off in the extreme ultraviolet spectral range and suppresses radiation below ˜10 eV photon energy by more than 8 orders of magnitude. It has an effective aperture of 73 mm without any support structure. A 0.35 μm thick polypropylene carrier foil is coated with metallic films of Al and Sn. We describe transmission measurements in the soft X-ray photon energy range to determine the thickness of the individual layers and present the optical performance data of the filter.

  18. Dose distribution in head and neck during dental x-ray procedures

    International Nuclear Information System (INIS)

    Mason, E.W.; Goepp, R.A.

    1978-01-01

    Previous studies, notably by Franklin (Angle Ortho., 43:53-64, 1973), have shown significant exposures during cephalometric dental procedures and ways in which these exposures can be reduced. Skin dose over thyroid tissue has been measured by Alcox (J. Am. Dent. Assoc., 88:568-579, 1974), and others. This study is an expansion of thyroid dose measurements by Block, Goepp, and Mason (Angle Ortho., 47:17-24, 1977). The internal dose distribution in the head and neck area due to cephalometric and panoramic dental x-ray procedures is shown along with the dependence of orbit and thyroid dose on patient positioning. Higher doses can be delivered to deep tissue by panoramic machines since tissue at the axis of rotation is exposed during the entire procedure. (author)

  19. Retention Characteristics of CBTi144 Thin Films Explained by Means of X-Ray Photoemission Spectroscopy

    Directory of Open Access Journals (Sweden)

    G. Biasotto

    2010-01-01

    Full Text Available CaBi4Ti4O15 (CBTi144 thin films were grown on Pt/Ti/SiO2/Si substrates using a soft chemical solution and spin-coating method. Structure and morphology of the films were characterized by the X-ray Diffraction (XRD, Fourier-transform infrared spectroscopy (FT-IR, Raman analysis, X-ray photoemission spectroscopy (XPS, and transmission electron microscopy (TEM. The films present a single phase of layered-structured perovskite with polar axis orient. The a/b-axis orientation of the ferroelectric film is considered to be associated with the preferred orientation of the Pt bottom electrode. XPS measurements were employed to understand the nature of defects on the retention behavior of CBTi144 films. We have observed that the main source of retention-free characteristic of the capacitors is the oxygen environment in the CBTi144 lattice.

  20. X-ray scattering evaluation of ultrastructural changes in human dental tissues with thermal treatment.

    Science.gov (United States)

    Sandholzer, Michael A; Sui, Tan; Korsunsky, Alexander M; Walmsley, Anthony Damien; Lumley, Philip J; Landini, Gabriel

    2014-05-01

    Micro- and ultrastructural analysis of burned skeletal remains is crucial for obtaining a reliable estimation of cremation temperature. Earlier studies mainly focused on heat-induced changes in bone tissue, while this study extends this research to human dental tissues using a novel quantitative analytical approach. Twelve tooth sections were burned at 400-900°C (30-min exposure, increments of 100°C). Subsequent combined small- and wide-angle X-ray scattering (SAXS/WAXS) experiments were performed at the Diamond Light Source synchrotron facility, where 28 scattering patterns were collected within each tooth section. In comparison with the control sample, an increase in mean crystal thickness was found in burned dentine (2.8-fold) and enamel (1.4-fold), however at a smaller rate than reported earlier for bone tissue (5-10.7-fold). The results provide a structural reference for traditional X-ray scattering methods and emphasize the need to investigate bone and dental tissues separately to obtain a reliable estimation of cremation temperature. © 2014 American Academy of Forensic Sciences.

  1. Moessbauer spectroscopy and X-ray diffraction study of 304 L stainless steel thin films

    International Nuclear Information System (INIS)

    Boubeker, B.; Eymery, J.P.; Goudeau, P.; Sayouty, E.H.

    1994-01-01

    304 L stainless steel films (SS) were elaborated using an ion-beam sputtering technique. The target material was a sheet of commercial grade 304 L SS. The starting material was first analysed by both conversion electron Moessbauer spectroscopy (CEMS) and X-ray diffraction. The nonmagnetic state and f.c.c. structure of this material were confirmed. The films were deposited on various substrates with thicknesses in the 175-800 nm range. The films are found to have both b.c.c. structure and ferromagnetic character. X-ray diffraction technique was also used in order to determine the residual stresses developed during the deposition process. The second stage of the work is devoted to the evolution of the film structure as a function of annealing treatments. So isochronal and isothermal kinetics at temperatures higher than 913 K have allowed to follow the alpha --> gamma phase transformation using X-ray diffraction and CEMS technique.The X-ray diffractograms reveal the existence of both b.c.c. and f.c.c. phases. Similar results can be deduced from Moessbauer spectra due to the single line coming from the non-magnetic phase and the sextet coming from the ferromagnetic phase. In addition the CEMS spectra reveal that the ferromagnetic component is split into two parts which indicates the existence of two iron sites. 1 fig., 4 refs.(author)

  2. Thin-film X-ray filters on microstructured substrates and their thermophysical properties

    Science.gov (United States)

    Mitrofanov, A. V.

    2018-02-01

    It is shown that structured substrates having micron- or submicron-sized through holes and coated with an ultrathin organic film can be used for the fabrication of thin-film X-ray filters via direct growth of functional layers on a substrate by sputter deposition, without additional complex processing steps. An optimised process is considered for the fabrication of X-ray filters on support structures in the form of electroplated fine nickel grids and on track-etched polymer membranes with micron- and submicrondiameter through pores. 'Optimisation' is here taken to mean matching the sputter deposition conditions with the properties of substrates so as to avoid overheating. The filters in question are intended for both imaging and single-channel detectors operating in the soft X-ray and vacuum UV spectral regions, at wavelengths from 10 to 60 nm. Thermal calculations are presented for the heating of ultrathin layers of organic films and thin-film support substrates during the sputter deposition of aluminium or other functional materials. The paper discusses approaches for cooling thinfilm composites during the sputter deposition process and the service of the filters in experiments and gives a brief overview of the works that utilised filters produced by the described technique on microstructured substrates, including orbital solar X-ray research in the framework of the CORONAS programme and laboratory laser plasma experiments.

  3. Residual stress estimation of ceramic thin films by X-ray diffraction and indentation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Atar, Erdem; Sarioglu, Cevat; Demirler, Ugur; Sabri Kayali, E.; Cimenoglu, Huseyin

    2003-05-15

    The residual stresses in ceramic thin films obtained by the indentation method have been found to be three times higher than those of the X-ray diffraction method. This discrepancy can be eliminated by setting the geometrical factor for the Vickers pyramid indenter to 1 in the relevant equation of the indentation method.

  4. Residual stress estimation of ceramic thin films by X-ray diffraction and indentation techniques

    International Nuclear Information System (INIS)

    Atar, Erdem; Sarioglu, Cevat; Demirler, Ugur; Sabri Kayali, E.; Cimenoglu, Huseyin

    2003-01-01

    The residual stresses in ceramic thin films obtained by the indentation method have been found to be three times higher than those of the X-ray diffraction method. This discrepancy can be eliminated by setting the geometrical factor for the Vickers pyramid indenter to 1 in the relevant equation of the indentation method

  5. Microscopic analysis on showers recorded as single core on X-ray films

    International Nuclear Information System (INIS)

    Amato, N.M.; Arata, N.; Maldonado, R.H.C.

    1983-01-01

    Cosmic-ray particles recorded as single dark spots on X-ray films with use of the emulsion chamber data of Brazil-Japan Collaboration are studied. Some results of microscopic analysis of such single-core-like showers on nuclear emulsion plates are reported. (Author) [pt

  6. X-ray and neutron scattering from amorphous diamondlike carbon and hydrocarbon films

    International Nuclear Information System (INIS)

    Findeisen, E.

    1994-10-01

    In this report amorphous, diamondlike, carbon and hydrocarbon films are investigated by two different methods, namely, X-ray scattering and a combination of X-ray and neutron reflectivity. As specular reflectivity probes the scattering length density profile of a sample perpendicular to its surface, the combination of X-ray and neutron reflectivity reveals the nuclei density of both carbon and hydrogen separately. This allows to calculate the concentration of hydrogen in the films, which varies in the presented experiments between 0 and 36 atomic %. This method is a new and nondestructive technique to determine the concentration of hydrogen within an error of about ±1 at. % in samples with sharp interfaces. It is well suited for thin diamondlike carbon films. X-ray scattering is used to obtain structural information on the atomic scale, especially the average carbon-carbon distance and the average coordination number of the carbon atoms. As grazing incidence diffraction experiments were not successful, free-standing films are used for the scattering experiments with synchrotron light. However, the scattered intensity for large scattering vectors is, in spite of the intense primary beam, very weak, and therefore the accuracy of the obtained structural parameter is not sufficient to prove the diamondlike properties also on the atomic scale. (au) (10 tabs., 76 ills., 102 refs.)

  7. Thin-film thickness measurement using x-ray peak ratioing in the scanning electron microscope

    International Nuclear Information System (INIS)

    Elliott, N.E.; Anderson, W.E.; Archuleta, T.A.; Stupin, D.M.

    1981-01-01

    The procedure used to measure laser target film thickness using a scanning electron microscope is summarized. This method is generally applicable to any coating on any substrate as long as the electron energy is sufficient to penetrate the coating and the substrate produces an x-ray signal which can pass back through the coating and be detected

  8. In-line X-ray lensless imaging with lithium fluoride film detectors

    International Nuclear Information System (INIS)

    Bonfigli, F.; Cecilia, A.; Bateni, S. Heidari; Nichelatti, E.; Pelliccia, D.; Somma, F.; Vagovic, P.; Vincenti, M.A.; Baumbach, T.; Montereali, R.M.

    2013-01-01

    In this work, we present preliminary in-line X-ray lensless projection imaging results at a synchrotron facility by using novel solid-state detectors based on non-destructive readout of photoluminescent colour centres in lithium fluoride thin films. The peculiarities of LiF radiation detectors are high spatial resolution on a large field of view, wide dynamic range, versatility and simplicity of use. These properties offered the opportunity to test a broadband X-ray synchrotron source for lensless projection imaging experiments at the TopoTomo beamline of the ANKA synchrotron facility by using a white beam spectrum (3–40 keV). Edge-enhancement effects were observed for the first time on a test object; they are discussed and compared with simulations, on the basis of the colour centre photoluminescence linear response found in the investigated irradiation conditions. -- Highlights: ► We performed broadband X-ray imaging at synchrotron by novel LiF imaging detectors. ► X-ray phase contrast experiments on LiF crystals and thin films were performed. ► Photoluminescent high-quality X-images on a LiF film only 1 μm thick were obtained. ► Edge-enhancement effects were detected and compared with simulations. ► A linearity of colour centre fluorescence response of LiF film was found

  9. Wavelength Dispersive X-ray Fluorescence Spectrometry for the Analysis of Organic Polymer Film

    International Nuclear Information System (INIS)

    Choi, Yong Suk; Park, Yong Joon; Kim, Jong Yun

    2008-01-01

    Recently, many studies have been focused on the thin films because there are numerous industrial processes relevant to thin films such as fuel cells, sensors, lubricants, coatings, and so on. Physical and chemical properties of solid surface have been modified by ultra-thin coatings such as Langmuir-Blodgett (LB) method with a variety of types of organic functional materials for the specific purposes in many applications. In addition, the layer-by-layer technique using polyelectrolyte films are now of interest as biosensors, electrochromic and electroluminescent devices, etc. In general, several methods such as X-ray or neutron reflectivity, and quartz crystal microbalance (QCM) have been utilized for the thin film analysis. These optical techniques can measure the film thicknesses up to hundreds of nanometers while X-ray photoelectron spectroscopy is widely used to study a few nanometers thick films. Other methods such as X-ray Photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atom force microscopy (AFM) have also been used in the film analysis in spite of some disadvantages for each method. X-ray fluorescence (XRF) has long been used as a rapid and simple analytical tool for the analysis of elemental composition of materials. XRF technique is suitable for on-line or in-line real-time monitoring because it is a non-destructive and rapid analysis with good precision and good accuracy at low cost. The aim of this work is to develop a new analytical technique for the quantitative analysis of polymer film on metal substrate. In the present study, Compton peak profile was investigated under different experimental conditions by using wavelength-dispersive XRF (WD-XRF). Compared to energy-dispersive XRF (ED-XRF), WD-XRF is more adequate in an accurate quantitative analysis of thin organic film

  10. Quality control of X-ray films with blue spectral sensitivity: comparative study

    International Nuclear Information System (INIS)

    Carrasco, F.; Ruiz Cruces, R.; Sendra, F.; Diez de los rios, A.

    1994-01-01

    In this work, seven X-ray films with blue-ultraviolet spectral sensitivity have been studied by means of light sensitometry, x-ray sensitometry and spatial resolution test. Three screens of different composition and speed were use. Only the films HPX44 and RG showed a high base plus for (>0,30), the remaining films maintained their values between 0,21 and 0,26. When blue light sensitometry was substituted by green light sensitometry, base plus fog practically did not show variations and gradient and speed changed less than 4% and 10% respectively. Speed and Gradient must be calculated from the relation between exposition and optical density, avoiding parameters referred to type optical density of a given step of the wedge. Two films with high speed (RG and HPX 44), four films with medium speed (Curix RP2, NewRX, Cronex 4 and X-Omat S) and one film with low speed but high resolution (Cronex 7) have been found. The obtained results present useful comparative data to select and adequate film according to the characteristic of the x-ray examination and the available screens. (Author)

  11. X-ray diffraction characterization of epitaxial CVD diamond films with natural and isotopically modified compositions

    Energy Technology Data Exchange (ETDEWEB)

    Prokhorov, I. A., E-mail: igor.prokhorov@mail.ru [Russian Academy of Sciences, Space Materials Science Laboratory, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics”, Kaluga Branch (Russian Federation); Voloshin, A. E. [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics” (Russian Federation); Ralchenko, V. G.; Bolshakov, A. P. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation); Romanov, D. A. [Bauman Moscow State Technical University, Kaluga Branch (Russian Federation); Khomich, A. A. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation); Sozontov, E. A. [National Research Centre “Kurchatov Institute” (Russian Federation)

    2016-11-15

    Comparative investigations of homoepitaxial diamond films with natural and modified isotopic compositions, grown by chemical vapor deposition (CVD) on type-Ib diamond substrates, are carried out using double-crystal X-ray diffractometry and topography. The lattice mismatch between the substrate and film is precisely measured. A decrease in the lattice constant on the order of (Δa/a){sub relax} ∼ (1.1–1.2) × 10{sup –4} is recorded in isotopically modified {sup 13}C (99.96%) films. The critical thicknesses of pseudomorphic diamond films is calculated. A significant increase in the dislocation density due to the elastic stress relaxation is revealed by X-ray topography.

  12. Lead iodide films as X-ray sensors tested in the mammography energy region

    International Nuclear Information System (INIS)

    Condeles, J.F.; Ghilardi Netto, T.; Mulato, M.

    2007-01-01

    We present an alternative method for the deposition of thin films of lead iodide (PbI 2 ), which is a promising semiconductor candidate for applications in medical digital radiography. The spray pyrolysis technique enables the fabrication of thick films with a deposition rate of about 3.3 As -1 . We investigate the influence of the main deposition parameters on the final properties of the films. They were substrate temperature from 150 up to 270 o C and nozzle-spray distance to substrate from 13.0 to 16.5 cm. The films were mainly investigated using X-ray diffraction (XRD), Atomic Force Microscopy (AFM), and Photoluminescence (PL) spectroscopy. Also, electrical characterizations were made in the dark as a function of temperature, and with the samples submitted to X-ray exposures in the energy range of mammography diagnosis

  13. Hard X-ray photoemission spectroscopy of transition-metal oxide thin films and interfaces

    International Nuclear Information System (INIS)

    Wadati, H.; Fujimori, A.

    2013-01-01

    Highlights: •Photoemission spectroscopy is a powerful technique to study the electronic structures of transition-metal oxides. •Hard X-ray photoemission spectroscopy (HXPES) is a new type of photoemission spectroscopy which can probe bulk states. •HXPES is very suitable for studying oxide thin films such as the composition dependence and the film thickness dependence. -- Abstract: Photoemission spectroscopy is a powerful experimental technique to study the electronic structures of solids, especially of transition-metal oxides. Recently, hard X-ray photoemission spectroscopy (HXPES) has emerged as a more relevant experimental technique to obtain clear information about bulk states. Here, we describe how HXPES can be conveniently applied to study the interesting subjects on oxide thin films such as the composition dependence and the film thickness dependence of the electronic structures and the interfacial electronic structure of multilayers

  14. Synchrotron-radiation-based X-ray micro-computed tomography reveals dental bur debris under dental composite restorations.

    Science.gov (United States)

    Hedayat, Assem; Nagy, Nicole; Packota, Garnet; Monteith, Judy; Allen, Darcy; Wysokinski, Tomasz; Zhu, Ning

    2016-05-01

    Dental burs are used extensively in dentistry to mechanically prepare tooth structures for restorations (fillings), yet little has been reported on the bur debris left behind in the teeth, and whether it poses potential health risks to patients. Here it is aimed to image dental bur debris under dental fillings, and allude to the potential health hazards that can be caused by this debris when left in direct contact with the biological surroundings, specifically when the debris is made of a non-biocompatible material. Non-destructive micro-computed tomography using the BioMedical Imaging & Therapy facility 05ID-2 beamline at the Canadian Light Source was pursued at 50 keV and at a pixel size of 4 µm to image dental bur fragments under a composite resin dental filling. The bur's cutting edges that produced the fragment were also chemically analyzed. The technique revealed dental bur fragments of different sizes in different locations on the floor of the prepared surface of the teeth and under the filling, which places them in direct contact with the dentinal tubules and the dentinal fluid circulating within them. Dispersive X-ray spectroscopy elemental analysis of the dental bur edges revealed that the fragments are made of tungsten carbide-cobalt, which is bio-incompatible.

  15. Magnetism in heterogeneous thin film systems: Resonant X-ray scattering studies

    International Nuclear Information System (INIS)

    Kortright, J.B.; Jiang, J.S.; Bader, S.D.; Hellwig, O.; Marguiles, D.T.; Fullerton, E.E.

    2002-01-01

    Magnetic and chemical heterogeneity are common in a broad range of magnetic thin film systems. Emerging resonant soft x-ray scattering techniques are well suited to resolve such heterogeneity at relevant length scales. Resonant x-ray magneto-optical Kerr effect measurements laterally average over heterogeneity but can provide depth resolution in different ways, as illustrated in measurements resolving reversible and irreversible changes in different layers of exchange-spring heterostructures. Resonant small-angle scattering measures in-plane heterogeneity and can resolve magnetic and chemical scattering sources in different ways, as illustrated in measurements of granular alloy recording media

  16. Imaging Local Polarization in Ferroelectric Thin Films by Coherent X-Ray Bragg Projection Ptychography

    Science.gov (United States)

    Hruszkewycz, S. O.; Highland, M. J.; Holt, M. V.; Kim, Dongjin; Folkman, C. M.; Thompson, Carol; Tripathi, A.; Stephenson, G. B.; Hong, Seungbum; Fuoss, P. H.

    2013-04-01

    We used x-ray Bragg projection ptychography (BPP) to map spatial variations of ferroelectric polarization in thin film PbTiO3, which exhibited a striped nanoscale domain pattern on a high-miscut (001) SrTiO3 substrate. By converting the reconstructed BPP phase image to picometer-scale ionic displacements in the polar unit cell, a quantitative polarization map was made that was consistent with other characterization. The spatial resolution of 5.7 nm demonstrated here establishes BPP as an important tool for nanoscale ferroelectric domain imaging, especially in complex environments accessible with hard x rays.

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  18. Synchrotron x-ray methods in studies of thin organic film structure

    International Nuclear Information System (INIS)

    Gentle, I.

    2002-01-01

    Full text: In recent years, the study of the structures of organic films as thin as a single monolayer has been revolutionized by methods that take advantage of the characteristics of synchrotron radiation. In particular, the methods of grazing incidence X-ray diffraction (GIXD) and X-ray reflectivity have led to a number of valuable insights into structural aspects of thin films at molecular resolution. Our group has been studying films formed at the air/water interface as insoluble monolayers and subsequently transferred to solid substrates using either the vertical (Langmuir-Blodgett) or horizontal (Langmuir-Schaeffer) methods. The main aim of these experiments is to exert control over film structure in the direction parallel to the substrate surface. This is highly desirable in order to design devices that exploit the optical and electrooptical properties of functional materials, but is difficult to do. By varying the chemical structure of the film materials and controlling deposition conditions a degree of control is possible, but only using synchrotron methods can it be easily verified. We have also developed a novel method of rapidly collecting data from GIXD measurements by the application of area detection (imaging plates), which has made possible measurements of dynamic processes such as in-situ annealing. Such measurements are not possible using traditional scanning methods. One area of current interest is films composed of porphyrins as functional materials, either alone or as mixed films with fatty acids. We have been investigating ways of assembling porphyrins in such a way as to overcome the tendency to aggregate, and to produce patterning and ordered structures in the plane of the interface. Examples will be given of how film composition and deposition method affects the final structure, and of how X-ray methods can be used to elucidate both the structures and the mechanisms. Copyright (2002) Australian X-ray Analytical Association Inc

  19. The use of a CCD imaging system for X-ray film intensity measurement

    International Nuclear Information System (INIS)

    Grigg, M.W.; Barnea, Z.

    1994-01-01

    The use of a simple CCD-based imaging system for digitizing and x-ray film image is demonstrated. A method of extending the region of linear response of the film based upon an analytic representation of the observed response to a series of increasing exposures is described. The validity of the procedure is illustrated through an example of the absolute intensity measurement of a reflection of cadmium sulphide. 3 refs., 7 figs

  20. Experimental elucidation: microscopic mechanism of resonant X-ray scattering in manganite films

    CERN Document Server

    Ohsumi, H; Kiyama, T

    2003-01-01

    Resonant X-ray scattering experiments have been performed on perovskite manganite La sub 0 sub . sub 5 Sr sub 0 sub . sub 5 MnO sub 3 thin films, which are grown on three distinct perovskite with a coherent epitaxial strain and have a forced ferro-type orbital ordering of Mn 3d orbitals. Using an interference technique, we have successfully observed the resonant X-ray scattering signal from the system having the ferro-type orbital ordering and also revealed the energy scheme of Mn 4p bands. For the forced ferro-type orbital ordering system, the present results evidence that the resonant X-ray scattering signal originates from the band structure effect due to the Jahn-Teller distortion of a MnO sub 6 octahedron, and not from the Coulomb interaction between 3d and 4p electrons. (author)

  1. Quality control of diagnostic x-ray equipment and film processing

    International Nuclear Information System (INIS)

    1993-01-01

    According to the section 40 of the Radiation Act (592/92), the licensee is required in Finland to make the arrangements to control the function of the radiation equipment and related facilities used for medical procedures. The guide explains how quality control can be organized for diagnostic x-ray equipment. It also gives recommendations for constancy tests for conventional x-ray radiographic and fluoroscopic equipment and for film processing. The recommendations are based on the publications and statements of the International Committee for Radiation Protection (ICRP) and standardization organizations. The intention is that the operators of x-ray equipment or the maintenance personnel are able to perform the quality control tests presented in the guide

  2. Roles of Thin Film Stress in Making Extremely Lightweight X-Ray Optics

    Science.gov (United States)

    Zhang, William W.

    2010-01-01

    X-ray optics typically must be coated with one of the noble metals, gold, platinum, or iridium, to enhance their photon collection area. In general, iridium is preferred to the other two because it generates the highest X-ray reflectivity in the I to 10 keV band. Unfortunately, iridium films typically have also the highest stress that can severely degrade the optical figure of the mirror substrate, resulting in a poorer image quality. In this paper we will report our work in understanding this stress and our method to counterbalance it. In particular we will also report on potential ways of using this stress to improve the substrate's optical figure, turning a bug into a desirable feature. This work is done in the context of developing an enabling technology for the International X-ray Observatory which is a collaborative mission of NASA, ESA, and JAXA, and expected to be launched into an L2 orbit in 2021.

  3. [Quality assurance from the viewpoint of the x-ray film industry].

    Science.gov (United States)

    von Volkmann, T

    1992-08-01

    The parameters of a film-screen-combination are listed in the directive to section 16 of the german X-ray Regulation. These parameters are determined by methods described in DIN standards and published by the manufacturer. Comparable but less precise parameters are determined in the Acceptance Test. For physical reasons it is not possible to determine the speed of an X-ray film or the intensification factor of a screen separately. The films, screens and processing chemicals delivered by the members of the manufacturer association ZVEI are kept below a deviation (expressed as relative contribution to the system speed S) of +/- 10% for the majority of products, the upper limit is +/- 15%. Poor storage and transport conditions may adversely affect the quality of X-ray films. A special labeling of the film box shall serve to guarantee safe distribution channels. The processing conditions are adjusted at the Acceptance Test according to the manufacturers recommendations. The Constancy Test of film processing serves to maintain these correct conditions. Methods deviating from the DIN-method are of limited (Bayerische method) or no value (Stuttgart method).

  4. Advances in thin film diffraction instrumentation by X-ray optics

    International Nuclear Information System (INIS)

    Haase, A.

    1996-01-01

    The structural characterisation of thin films requires a parallel X-ray beam of high intensity. Parallel beam geometry is commonly used in high resolution and single crystal experiments, but also in the field of X-ray diffraction for polycrystalline material (e.g. in phase, texture and stress analysis). For grazing incidence diffraction (GID), the use of small slits on the primary side and of long soller slits with a flat monochromator on the secondary side is standard. New optical elements have been introduced with polychromatic or monochromatic radiation. By means of different applications the results are compared with those of classical beam optics. X-ray fiber optics utilize total external reflection of X-rays on smooth surfaces. Effects of monochromatization are presented. In many fields of application, fiber optics may replace conventional collimators. The use of primary and secondary channel cut crystals can also produce a high parallel monochromatic X-ray beam. A parabolically bent graded multilayer produces a monochromatic parallel beam of high intensity. Compared with classical Bragg-Brentano (focussing) geometry, excellent results have been obtained, especially for samples with an irregular shape. In combination with a channel cut monochromator there is a substantial gain in intensity leading to an increase of the dynamic intensity range of rocking curves

  5. Advances in thin film diffraction instrumentation by X-ray optics

    Energy Technology Data Exchange (ETDEWEB)

    Haase, A [Rich. Seifert and Co., Analytical X-ray Systems, Ahrensburg (Germany)

    1996-09-01

    The structural characterisation of thin films requires a parallel X-ray beam of high intensity. Parallel beam geometry is commonly used in high resolution and single crystal experiments, but also in the field of X-ray diffraction for polycrystalline material (e.g. in phase, texture and stress analysis). For grazing incidence diffraction (GID), the use of small slits on the primary side and of long soller slits with a flat monochromator on the secondary side is standard. New optical elements have been introduced with polychromatic or monochromatic radiation. By means of different applications the results are compared with those of classical beam optics. X-ray fiber optics utilize total external reflection of X-rays on smooth surfaces. Effects of monochromatization are presented. In many fields of application, fiber optics may replace conventional collimators. The use of primary and secondary channel cut crystals can also produce a high parallel monochromatic X-ray beam. A parabolically bent graded multilayer produces a monochromatic parallel beam of high intensity. Compared with classical Bragg-Brentano (focussing) geometry, excellent results have been obtained, especially for samples with an irregular shape. In combination with a channel cut monochromator there is a substantial gain in intensity leading to an increase of the dynamic intensity range of rocking curves.

  6. Guides for intraoral x-rays

    International Nuclear Information System (INIS)

    Ogunsunlade, O.A.

    1988-01-01

    An h-shaped exterior guide for use in combination with a SNAP-A-RAY film holder for accurately aligning a beam from an X-ray cone with an X-ray film during the process of taking intraoral periapical dental X-rays of the maxillary and mandibular teeth is described comprising: a first guide arm laterally and detachably connectable through a housing means; a traverse arm extending from the midpoint of the first guide arm and parallel to the X-ray film; and a second guide arm extending perpendicularly from an end of the traverse arm toward a plane of the X-ray film and in parallel relation up to an end point of the first guide arm

  7. X-ray diffraction and X-ray absorption of strained CoO and MnO thin films

    NARCIS (Netherlands)

    Csiszár, Szilárd Istvan; Tjeng, L.H

    2005-01-01

    The aim of this project was to study the influence of epitaxial strain on the electronic and magnetic structure of transition metal oxide layers. In the first part of the thesis the discovery of characteristic diffuse X-ray scattering patterns is reported. They are caused by the misfit dislocations,

  8. Drywall plates evaluation as protection barriers in dental X-rays and mammography facilities; Evaluacion de placas de drywall como barreras de proteccion en instalaciones de rayos X dental y mamografia

    Energy Technology Data Exchange (ETDEWEB)

    Guevara R, V. Y.; Romero C, N. [Empresa QC DOSE S. A. C., Av. Tomas Marsano 1915, Surquillo, Lima 34 (Peru); Berrocal T, M., E-mail: vguevara@qcdose.com [Universidad Nacional Mayor de San Marcos, C. German Amezaga 375, Edif. Jorge Basadre, Ciudad Universitaria, Lima 1 (Peru)

    2014-08-15

    In the dental X-rays and mammography facilities, usually lead shielded walls as protective barriers are used. Lead is a good attenuator for X-rays, but has toxic properties and its cost is high. Mammography equipment s emit low-energy photons in the range of 25 keV to 35 keV, on current computers; the primary radiation beam is intercepted by the image receptor. Peri apical dental equipment s emit photons in the range of 50 to 90 keV, their filtration is fixed. These devices emit a collimated beam whose diameter is slightly larger than the diagonal dimension of a standard film of dental X-rays. When a dental x-ray is performed, the radiation beam is partially attenuated by the patient. Drywall is a material consisting of plasterboard between two cardboard layers, being its components gypsum and cellulose generally. It is used in construction for execution of interior walls, ceilings and wall coverings, could also serve as a replacement for lead as well as other materials. In this paper three drywall prototypes (Giplac), formed with 02, 04 and 06 drywall layers (13, 16 and 20 cm of thickness respectively) were tested as barriers against primary and secondary X-ray radiation that come from dental and mammography equipment s. The results show that the drywall prototype, 02 layers, efficiently attenuates the secondary radiation beam produced by conventional mammography equipment. And the prototype 04 and 06 layers, efficiently attenuates the primary radiation beam produced by peri apical dental equipment. (author)

  9. Sputter deposition of PZT piezoelectric films on thin glass substrates for adjustable x-ray optics.

    Science.gov (United States)

    Wilke, Rudeger H T; Johnson-Wilke, Raegan L; Cotroneo, Vincenzo; Davis, William N; Reid, Paul B; Schwartz, Daniel A; Trolier-McKinstry, Susan

    2013-05-10

    Piezoelectric PbZr(0.52)Ti(0.48)O(3) (PZT) thin films deposited on thin glass substrates have been proposed for adjustable optics in future x-ray telescopes. The light weight of these x-ray optics enables large collecting areas, while the capability to correct mirror figure errors with the PZT thin film will allow much higher imaging resolution than possible with conventional lightweight optics. However, the low strain temperature and flexible nature of the thin glass complicate the use of chemical-solution deposition due to warping of the substrate at typical crystallization temperatures for the PZT. RF magnetron sputtering enabled preparation of PZT films with thicknesses up to 3 μm on Schott D263 glass substrates with much less deformation. X-ray diffraction analysis indicated that the films crystallized with the perovskite phase and showed no indication of secondary phases. Films with 1 cm(2) electrodes exhibited relative permittivity values near 1100 and loss tangents below 0.05. In addition, the remanent polarization was 26 μC/cm(2) with coercive fields of 33 kV/cm. The transverse piezoelectric coefficient was as high as -6.1±0.6 C/m(2). To assess influence functions for the x-ray optics application, the piezoelectrically induced deflection of individual cells was measured and compared with finite-element-analysis calculations. The good agreement between the results suggests that actuation of PZT thin films can control mirror figure errors to a precision of about 5 nm, allowing sub-arcsecond imaging.

  10. Development of a dosimetric system for dental X-ray equipment quality control

    International Nuclear Information System (INIS)

    Melo, Francisco Almeida de

    2002-08-01

    An electronic instrument with digital readout was designed and constructed to provide fast, simple and non-invasive measurements of X-ray dental equipment parameters. This instrument is capable of evaluating the entrance dose, exposure time, tube voltage (kVp) and beam filtration. It consists of a set of five photodiodes connected each one in the photocurrent mode to the input of a designed integrating electrometer. Three of the detectors are fixed under aluminium filters with different thicknesses, one is fixed under a 0.3 mm copper filter and the other has no filtration. The readings of the three detectors under aluminium filters and of the bare detector permit the determination of the half-value layer, which is used to calculate the beam filtration. The ratio between the readings of the detector below the copper filter and the one without filtration is used to determine the tube voltage. The signal produced by the detector without filter is used to evaluate the patient entrance dose, and to active an electronic timer for measuring the real exposure time. The tests and calibration of the instrument in different voltages in the 59 - 70kVp range, showed that its response is both stable and reproducible to within 1%. The instrument response was compared to the one from a commercial non-invasive X-ray test equipment (Gammex RMI Multifunction kVp meter). The results showed that the response of the developed instrument is in good agreement with the RMI meter which is the standard equipment for such measurements. These results indicate that the dosimetric system is suitable for use in Dental Quality Assurance Programs. (author)

  11. X-ray-induced thinning of 3He and 3He/4He mixture films

    International Nuclear Information System (INIS)

    Penanen, Konstantin; Fukuto, Masafumi; Silvera, Isaac F.; Pershan, Peter

    2000-01-01

    Films of isotopic mixtures of helium have been studied using x-ray specular reflectivity techniques. In contrast with superfluid 4 He films, x-ray exposure causes a reduction in the thickness of 4 He films above the superfluid transition as well as films of pure 3 He and 3 He/ 4 He mixtures. One proposed model that could account for this effect is a charging model, in which thinning is caused by electrostatic pressure of free charges that accumulate on the helium surface. Unfortunately, this model is not fully consistent with all of the experimental observations. A localized heating model, in which indirect heating of the film causes it to thin would explain the data if there were dissipative film flow in the 3 He/ 4 He mixtures at temperatures where the bulk is superfluid. We argue that various published experimental results suggest such an effect. In this model, film thinning data for dilute 3 He/ 4 He films indicates dissipation that is linear in 3 He content of the film over two orders of magnitude

  12. A method of simultaneous no-screen X-ray film taking with direct twofold magnification of hands and feet

    International Nuclear Information System (INIS)

    Zajgner, J.; Szymanska-Prach, H.

    1978-01-01

    The authors propose an original method of X-ray examination of hands and feet which makes possible simultaneous radiography without screen and direct twofold magnified film taking. The method is not connected with the necessity of exposing the patient to an additional dose of X-rays. It has been tried in 20 patients with suspected rheumatoid arthritis. It requires an X-ray tube with 0.3 x 0.3 mm microfocus. (author)

  13. New intraoral x-ray fluorographic imaging for dentistry

    International Nuclear Information System (INIS)

    Higashi, T.; Osada, T.; Aoyama, W.; Iguchi, M.; Suzuki, S.; Kanno, M.; Moriya, K.; Yoshimura, M.; Tusuda, M.

    1983-01-01

    A new dental x-ray fluorographic unit has been developed. This unit is composed of small intraoral x-ray tube, a compact x-ray image intensifier, and a high-resolution TV system. The purposes for developing this equipment were to (1) directly observe the tooth during endodontic procedures and (2) reduce x-ray exposure to the patient and the dentist. The radiation exposure can be reduced to about 1/600 the exposure used with conventional dental film. In clinical trials, a satisfactory fluorographic dental image for endodontic treatment was obtained with this new device

  14. Development of NaI(Tl) scintillating films for imaging soft x-rays

    International Nuclear Information System (INIS)

    Shepherd, J.A.

    1993-01-01

    Thin film NaI(Tl) scintillators, of areas of up to 130 cm 2 , have been fabricated and characterized for use on soft x-ray imaging photomultiplier tubes. Relevant parameters of photon-counting imaging detectors are defined and used to predict the performance of several materials, including CsI(Na), CsI(Tl), CaF 2 (Eu), Lu 2 (SiO 4 )O:Ce, and NaI(Tl), as thin film scintillators on fiber optic substrates. Also, x-ray imaging methodologies are compared. The NaI(Tl) films were vapor-deposited onto quartz and fiber optic substrates using a powder flash deposition technique. When compared to single crystal NaI(Tl), the films were found to have equally high light yield but lower energy resolution. Light yield optimization was studied in detail including the effects of substrate temperature, activator concentration in the evaporant, and boat temperature. Spatial resolution as well as parallax errors are discussed and measured for film thicknesses up to 61 μm. A technique is described that can substantially increase the light collection of high index films on fiber optic disks. The light collection was improved by 20% by coating the disk with potassium silicate before the NaI(Tl) deposition. Large area films, up to 130 cm 2 , had a spatial uniformity of response within ±1.5% for count rate and ±3.5% for light yield, and their spatial resolution exceeded 16.6 lp mm -1 when deposited onto fiber optic substrates. The 8-keV x-ray detection efficiency of the microchannel plate imaging photomultiplier tube coupled to a NaI(Tl) film scintillator is predicted to be 88%. Other uses for the films are also described

  15. Nondestructive characterization of surface chemical wear films via X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Hershberger, J.; Ajayi, O.O.; Fenske, G.R

    2004-01-15

    This work describes and demonstrates a suite of techniques for the non-destructive examination of surface films formed from oil additives. X-Ray diffraction, reflectivity and fluorescence have been used in grazing-incidence geometry to provide information on the thickness, roughness, density, structure and composition of the layers that compose reaction films. The lubricating oils were not rinsed off the surfaces of the samples before analysis. Films were formed from neat polyalphaolefin (PAO) oil and PAO with chloroform, dimethyl disulfide, or zinc or molybdenum dialkyl dithiophosphate additive. A thick layer of crystalline FeO formed during wear lubricated by neat PAO.

  16. Crossover And MTF Characteristics Of A Tabular-Grain X-Ray Film

    Science.gov (United States)

    Huff, K. E.; Wagner, P. W.

    1984-08-01

    An orthochromatic x-ray film made with tabular silver halide grains has a significantly higher MTF when exposed with green-emitting intensifying screens than do conventional films with similar sensitometric properties. The primary reason for the improved MTF is a decrease in the amount of crossover exposure, i.e., exposure by light that has crossed the support one or more times. Two well-established sensitometric procedures for measuring crossover have been compared. One produces results accurate enough for calculations of MTF relationships. Calculated MTF relationships for tabulargrain and conventional films are compared with measured values.

  17. X-ray film interferometer as an instrument for semiconductor heterostructure investigation

    CERN Document Server

    Vasilenko, A P; Nikitenko, S G; Fedorov, A A; Sokolov, L V; Nikiforov, A I; Trukhanov, E M

    2001-01-01

    Translation Moire pictures were first observed in interference topographs obtained using Synchrotron radiation. A film interferometer was prepared on the base of the GeSi heterosystem. Another film interferometer, which presents the heterosystem of epitaxial Si/ porous Si/ substrate Si, permitted us to observe a decrease in the bending of the film atomic planes at annealing of the heterosystem. This bend smoothing was calculated with the sensitivity better than 1 A with the use of X-ray interference topographs. Contrast peculiarities in Moire pictures are discussed for nondiffracting layers and crystal quantum wells.

  18. Probing molecular orientations in thin films by x-ray photoelectron spectroscopy

    Science.gov (United States)

    Li, Y.; Li, P.; Lu, Z.-H.

    2018-03-01

    A great number of functional organic molecules in active thin-film layers of optoelectronic devices have highly asymmetric structures, such as plate-like, rod-like, etc. This makes molecular orientation an important aspect in thin-films as it can significantly affect both the optical and electrical performance of optoelectronic devices. With a combination of in-situ ultra violet photoelectron spectroscopy (UPS) and x-ray photoelectron spectroscopy (XPS) investigations for organic molecules having a broad range of structural properties, we discovered a rigid connection of core levels and frontier highest occupied molecular orbital levels at organic interfaces. This finding opens up opportunities of using X-ray photoemission spectroscopy as an alternative tool to UPS for providing an easy and unambiguous data interpretation in probing molecular orientations.

  19. Probing molecular orientations in thin films by x-ray photoelectron spectroscopy

    Directory of Open Access Journals (Sweden)

    Y. Li

    2018-03-01

    Full Text Available A great number of functional organic molecules in active thin-film layers of optoelectronic devices have highly asymmetric structures, such as plate-like, rod-like, etc. This makes molecular orientation an important aspect in thin-films as it can significantly affect both the optical and electrical performance of optoelectronic devices. With a combination of in-situ ultra violet photoelectron spectroscopy (UPS and x-ray photoelectron spectroscopy (XPS investigations for organic molecules having a broad range of structural properties, we discovered a rigid connection of core levels and frontier highest occupied molecular orbital levels at organic interfaces. This finding opens up opportunities of using X-ray photoemission spectroscopy as an alternative tool to UPS for providing an easy and unambiguous data interpretation in probing molecular orientations.

  20. Calibration of screen-type X-ray films for electron beams

    International Nuclear Information System (INIS)

    Kobayashi, T.; Sato, Y.; Yoshida, K.; Tateyama, N.; Komori, Y.; Nakabayashi, T.; Oyamada, M.; Nishimura, J.

    2002-01-01

    In order to extract the maximum performance of the screen-type X-ray film for the detection of cascade showers in emulsion chambers, we examined the effect of the thickness of the phosphor screen by irradiation with 200 MeV electron beams. The observed data is in agreement with our analytical prediction of the radiative transfer of photons in a phosphor screen. If we use a combination of the specially prepared screen, HR16B, with a phosphor layer of 400 μm and a green-sensitive X-ray film, HA30, the detection threshold energy of cascade showers can be considerably lowered down to 140 GeV. (author)

  1. Calibration of screen-type X-ray films for electron beams

    CERN Document Server

    Kobayashi, T; Yoshida, K; Tateyama, N; Komori, Y; Nakabayashi, T; Oyamada, M; Nishimura, J

    2002-01-01

    In order to extract the maximum performance of the screen-type X-ray film for the detection of cascade showers in emulsion chambers, we examined the effect of the thickness of the phosphor screen by irradiation with 200 MeV electron beams. The observed data is in agreement with our analytical prediction of the radiative transfer of photons in a phosphor screen. If we use a combination of the specially prepared screen, HR16B, with a phosphor layer of 400 mu m and a green-sensitive X-ray film, HA30, the detection threshold energy of cascade showers can be considerably lowered down to 140 GeV. (author)

  2. Dose reduction by x-ray beam filtration in screen-film radiography

    International Nuclear Information System (INIS)

    Koedooder, C.

    1986-01-01

    This thesis describes experimental and theoretical aspects of dose reduction by x-ray beam filtration in screen-film radiography. The thesis deals mainly with dose reduction under the constraint of constant image quality; an analytical approach is chosen. Therefore, part of the thesis deals with the development of an algorithm to calculate patient dose and exposure for different filter materials and different tube load conditions, under the constraint of constant contrast and constant optical density. (Auth.)

  3. Thin films and buried interfaces characterization with X-ray standing waves

    Energy Technology Data Exchange (ETDEWEB)

    Lagomarsino, S [CNR, Rome (Italy). Istituto Elettronica Stato Solido

    1996-09-01

    The X-ray standing wave techniques is a powerful, non destructive method to study interfaces at the atomic level. Its basic features are described here together with the peculiarities of its applications to epitaxial films and buried interfaces. As examples of applications, experiments carried out on Si/silicide interfaces, on GaAs/InAs/GaAs buried interfaces and on Si/Ge superlattices are shown.

  4. Design and construction of a computerized optical densitometer for X-ray films

    International Nuclear Information System (INIS)

    Vicuna V, H.G.; Picon C, C.; Zaharia B, M.

    1998-01-01

    In Radiotherapy Departments, where it is disposed of radiation units, these require of a control quality of their parameters as: dose in depth, real size, symmetry and levelling of the radiation field. In order to fulfil above it was designed and built a totally automated system for scanning and analysing the X-ray films or plates, which serve to have the parameter information to be measured. (Author)

  5. X-ray quantum optics with Moessbauer nuclei in thin-film cavities

    Energy Technology Data Exchange (ETDEWEB)

    Heeg, Kilian Peter

    2014-12-09

    In this thesis thin-film cavities with embedded Moessbauer nuclei probed by near-resonant X-ray light are studied from a quantum optical perspective. A theoretical framework is developed and compact expressions for the observables are derived for the linear excitation regime, which is encountered in current experiments. Even advanced cavity layouts can be modeled in excellent agreement with the results of previous experiments and semi-classical approaches. In the absence of magnetic hyperfine splitting, the spectral response of the system is found to be formed by tunable Fano profiles. An experimental implementation of this line shape control allows to extract spectroscopic signatures with high precision and to reconstruct the phase of the nuclear transition in good agreement with the theoretical predictions. The alignment of medium magnetization and polarization control of the X-rays enable to engineer advanced quantum optical level schemes, in which vacuum induced coherence effects are predicted and successfully demonstrated in an experiment. Furthermore, it is shown that group velocity control for x-ray pulses can be achieved in the cavity. A scheme for its observation is proposed and then employed to experimentally confirm sub-luminal X-ray propagation. Finally, non-linear effects, which could become accessible with future light sources, are explored and a non-linear line shape control mechanism is discussed.

  6. MRI of atlantoaxial subluxation; Correlating with plain X-ray films and CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Saikawa, Yuko; Nishi, Naoko; Saitoh, Yoko; Akimura, Rumiko; Sasaki, Taisuke; Yodono, Hiraku; Takekawa, Shoichi; Harata, Seikou; Sannohe, Akio (Hirosaki Univ., Aomori (Japan). School of Medicine)

    1991-04-01

    Twenty-three patients with atlantoaxial subluxation (14 with rheumatoid arthritis, one each with rheumatoid arthritis and Arnold-Chiari malformation, os odontoideum, Klippel-Feil syndrome, trauma, and 5 with unknown causes) were evaluated with MRI. We used 0.5 T MRI unit (RESONA; Yokogawa Medical Systems, Japan) and 1.5 T MRI unit (SMT 150; Shimazu, Japan) with head or flexible coils. We compared the usefulness of MRI with those of plain X-ray films and CT regarding several points. MRI provided better image of the soft tissue mass around the odontoid process, compression of cord or subarachnoid space than plain X-ray films and CT. Atlanto-odontoid distance on MRI is nearer to that on plain X-ray films than CT. MRI is useful in analyzing the anatomic details such as transverse ligament, alar ligament, tectorial membrane and thickened synovium. Both MRI and CT provided detailed bony changes. High correlation was observed between MRI grading of cord compression and the degree of myelopathy. (author).

  7. Development and exploitation of the slit method for the characterization of x-ray screen-film combinations

    International Nuclear Information System (INIS)

    Hoeschen, D.

    1987-01-01

    For the determination of the modulation transfer function (MTF) of screen-film combinations which are used in medical x-ray diagnostics a measuring method has been developed: the screen-film combination is exposed to x-rays behind a thin slit and the modulation transfer function is calculated from the resulting rather broad slit images on the film. After solving many technical and photographic problems, the slit method provides high precision in the MTF determination. The only objection against this method is the necessary high dose variation which has to be provided by the x-ray machine

  8. In-situ x-ray absorption study of copper films in ground water solutions

    International Nuclear Information System (INIS)

    Kvashnina, K.O.; Butorin, S.M.; Modin, A.; Soroka, I.; Marcellini, M.; Nordgren, J.; Guo, J.-H.; Werme, L.

    2007-01-01

    This study illustrates how the damage from copper corrosion can be reduced by modifying the chemistry of the copper surface environment. The surface modification of oxidized copper films induced by chemical reaction with Cl - and HCO 3 - in aqueous solutions was monitored by in situ X-ray absorption spectroscopy. The results show that corrosion of copper can be significantly reduced by adding even a small amount of sodium bicarbonate. The studied copper films corroded quickly in chloride solutions, whereas the same solution containing 1.1 mM HCO 3 - prevented or slowed down the corrosion processes

  9. Structure of ordered polyelectrolyte films from atomic-force microscopy and X-ray reflectivity data

    International Nuclear Information System (INIS)

    Belyaev, V.V.; Tolstikhina, A.L.; Stepina, N.D.; Kayushina, R.L.

    1998-01-01

    The possible application of atomic-force microscopy and X-ray reflectometry methods to structural studies of polyelectrolyte films obtained due to alternating adsorption of oppositely charged polyanion [sodium polysterenesulfonate (PSS)] and polycation [poly(allylamine) hydrochloride (PAA)] layers on solid substrates has been considered. The atomic-force microscopy study has revealed the characteristic features of the surface topography of samples consisting of different numbers of polyelectrolyte layers deposited from solutions characterized by different ionic strength values. It is shown that the shape of the reflectivity curves obtained from thin polyelectrolyte films depends on their surface structure

  10. Analysis of Ti/Mo film by X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Mou Fangming; Tu Bing; Yao Bing; Liu Jinhua; Long Xinggui

    2002-01-01

    Chemical elements and their electronic binding energy on surface of Ti film and bulk are analyzed by X-ray photoelectron spectroscopy (XPS) and Ar + etching. The results show that the surface of specimens is contaminated by carbon and oxygen. Mo on surface of Ti film is from substrate. The XPS spectra of Ti 2p of the etched specimens are fitted on. The results show that Ti chemical states on surface of Ti film are TiO 2 with a content of approaching to 100% and a little Ti. Some TiO 2 will be reduced to low chemical states with the increasing of etching time. The chemical states of Mo on surface of Ti film are MoO 3 and Mo. The content of Mo increases as etching time increasing. Chemical state of carbon on the surface of film is graphite and carbide with binding energy of 288.2-288.9 eV

  11. Grazing incidence X-ray absorption characterization of amorphous Zn-Sn-O thin film

    Science.gov (United States)

    Moffitt, S. L.; Ma, Q.; Buchholz, D. B.; Chang, R. P. H.; Bedzyk, M. J.; Mason, T. O.

    2016-05-01

    We report a surface structure study of an amorphous Zn-Sn-O (a-ZTO) transparent conducting film using the grazing incidence X-ray absorption spectroscopy technique. By setting the measuring angles far below the critical angle at which the total external reflection occurs, the details of the surface structure of a film or bulk can be successfully accessed. The results show that unlike in the film where Zn is severely under coordinated (N < 4), it is fully coordinated (N = 4) near the surface while the coordination number around Sn is slightly smaller near the surface than in the film. Despite a 30% Zn doping, the local structure in the film is rutile-like.

  12. In situ X-ray diffraction studies on the piezoelectric response of PZT thin films

    Energy Technology Data Exchange (ETDEWEB)

    Davydok, A., E-mail: davydok@mpie.de [Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397 Marseille (France); Max-Planck-Institut für Eisenforschung, Department Structure and Nano-/Micromechanics of Materials, D-40237 Düsseldorf (Germany); Cornelius, T.W. [Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397 Marseille (France); Mocuta, C. [SOLEIL Synchrotron, DiffAbs beamline, L' Orme des Merisiers, Saint-Aubin - BP 48, 91192 Gif-sur-Yvette Cedex (France); Lima, E.C. [Universidade Federal do Tocantins, 77500-000 Porto Nacional, TO (Brazil); Araujo, E.B. [Departamento de Fisica e Quimica, Universidade Estadual Paulista, Av. Brasil, 56 Centro, 15385-000 Ilha Solteira, SP (Brazil); Thomas, O. [Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397 Marseille (France)

    2016-03-31

    Piezoelectric properties of randomly oriented self-polarized PbZr{sub 0.50}Ti{sub 0.50}O{sub 3} (PZT) thin films were investigated using in situ synchrotron X-ray diffraction. Possibilities for investigating the piezoelectric effect using micro-sized hard X-ray beams are demonstrated and perspectives for future dynamical measurements on PZT samples with variety of compositions and thicknesses are given. Studies performed on the crystalline [100, 110] directions evidenced piezoelectric anisotropy. The piezoelectric coefficient d{sub 33} was calculated in terms of the lab reference frame (d{sub perp}) and found to be two times larger along the [100] direction than along the [110] direction. The absolute values for the d{sub perp} amount to 120 and 230 pm/V being in good agreement with experimental and theoretical values found in literature for bulk PZT ceramics. - Highlights: • We performed in situ synchrotron X-ray diffraction studies on (PZT) thin films. • We discuss anisotropy of piezo effect in different crystallographic directions. • Perpendicular component Piezo coefficient of thin PZT layer is defined.

  13. Application of X-ray fluorescence (WDXRF): thickness and chemical composition determination of thin films

    International Nuclear Information System (INIS)

    Scapin, Valdirene de Oliveira.

    2004-01-01

    In this work a procedure is described for thickness and quantitative chemical composition of thin films by wavelength dispersion X-ray fluorescence (WDXRF) using Fundamental Parameters method. This method was validated according to quality assurance standard and applied sample Al, Cr, TiO2, Ni, ZrO2 (single thickness) and Ni/Cr (double thickness) on glass; Ni on steel and metallic zinc and TiO2 on metallic iron (single thickness), all the sample were prepared for physical deposition of vapor (PVD). The thickness had been compared with Absorption (FRX-A) and Rutherford Backscattering Spectrometry (RBS) methods; the result showed good efficiency of the fundamental parameters method. Sample structural characteristics analyzed by X ray diffraction (XRD) showed any influence in the thickness determinations. (author)

  14. Determination of diffusion profiles in thin film couples by means of X-ray-diffraction

    International Nuclear Information System (INIS)

    Wagendristel, A.

    1975-01-01

    An X-ray method for the determination of concentration profiles in thin film diffusion couples is presented. This method is based on the theory of Fourier analysis of X-ray diffraction profiles which is generalized to polycrystalline samples showing non-uniform lattice parameter. A Fourier synthesis of the concentration spectrum is possible when the influences of the particle size and the strain in the sample as well as the instrumental function are eliminated from the measured diffraction profile. This can be done by means of reference profiles obtained from layers of the diffusion components. Absorption of the radiation in the sample is negligible when diffusion couples of symmetrical sandwich structure are used. The method is tested experimentally in the system Au-Cu. (orig.) [de

  15. In situ X-ray synchrotron study of organic semiconductor ultra-thin films growth

    International Nuclear Information System (INIS)

    Moulin, J.-F.; Dinelli, F.; Massi, M.; Albonetti, C.; Kshirsagar, R.; Biscarini, F.

    2006-01-01

    In this work we present an X-ray diffraction study of the early stages of growth of an organic semiconductor (sexithiophene, T 6 ) thin film prepared by high vacuum sublimation. Specular reflectometry and grazing incidence X-ray diffraction were used to monitor the formation of T 6 films on silicon oxide. Our results show that T 6 grows as a crystalline layer from the beginning of the evaporation. The reflectometry analysis suggests that, in the range of rates and temperatures studied, the growth is never layer by layer but rather 3D in nature. In-plane GIXD has allowed us to observe for the first time a thin film phase of T 6 formed of molecules standing normal to the substrate and arranged in a compressed unit cell with respect to the bulk, i.e. the unit cell parameters b and c are relatively smaller. We have followed the dynamics of formation of this new phase and identified the threshold of appearance of the bulk phase, which occurs above ∼5-6 monolayers. These results are relevant to the problem of organic thin film transistors, for which we have previously demonstrated experimentally that only the first two monolayers of T 6 films are involved in the electrical transport. The layers above the second one do not effectively contribute to charge mobility, either because they are more 'disordered' or because of a screening of the gate field

  16. A study on developpement of guideline on writing technical document for electrical medical devices: Dental x-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Youl; Kim, Jae Ryang; Lee, Jun Ho; Park, Chang Won [Division of Medical Device Research, National Institute of Food and Drug Safety Evaluation, Mnistry of Food and Drug Safety (Korea, Republic of)

    2016-12-15

    Due to recent population aging, the number of check-up for senior citizens has increased steadily. According to this trend, the market size of dental X-ray equipment and the number of approval and review for these devices have simultaneously increased. The technical document of medical device is required for approval and review for medical device, and medical device companies needs to have work comprehension and expertise, as the document needs to include the overall contents such as performances, test criteria, etc.. Yet, since most of domestic manufacturers or importers of medical devices are small businesses, it is difficult for them to recruit professional manpower for approval of medical devices, and submission of inaccurate technical documents has increased. These problems lead to delay of the approval process and to difficulties in quick entering into the market. Especially, the Ministry of Food and Drug safety (MFDS) standards of a dental extra-oral X-ray equipment, a dental intra-oral X-ray equipment, an arm-type computed tomography, and a portable X-ray system have been recently enacted or not. this guideline of dental X-ray equipment adjusting revised standards was developed to help relative companies and reviewers. For this study, first, the methods to write technical document have been reviewed with revised international and domestic regulations and system. Second, the domestic and foreign market status of each item has been surveyed and analyzed. Third, the contents of technical documents already approved by MFDS have been analyzed to select the correct example, test items, criteria, and methods. Finally, the guideline has been developed based on international and domestic regulation, through close review of a consultative body composed of academic, industrial, research institute and government experts.

  17. A study on developpement of guideline on writing technical document for electrical medical devices: Dental x-ray equipment

    International Nuclear Information System (INIS)

    Lee, Seung Youl; Kim, Jae Ryang; Lee, Jun Ho; Park, Chang Won

    2016-01-01

    Due to recent population aging, the number of check-up for senior citizens has increased steadily. According to this trend, the market size of dental X-ray equipment and the number of approval and review for these devices have simultaneously increased. The technical document of medical device is required for approval and review for medical device, and medical device companies needs to have work comprehension and expertise, as the document needs to include the overall contents such as performances, test criteria, etc.. Yet, since most of domestic manufacturers or importers of medical devices are small businesses, it is difficult for them to recruit professional manpower for approval of medical devices, and submission of inaccurate technical documents has increased. These problems lead to delay of the approval process and to difficulties in quick entering into the market. Especially, the Ministry of Food and Drug safety (MFDS) standards of a dental extra-oral X-ray equipment, a dental intra-oral X-ray equipment, an arm-type computed tomography, and a portable X-ray system have been recently enacted or not. this guideline of dental X-ray equipment adjusting revised standards was developed to help relative companies and reviewers. For this study, first, the methods to write technical document have been reviewed with revised international and domestic regulations and system. Second, the domestic and foreign market status of each item has been surveyed and analyzed. Third, the contents of technical documents already approved by MFDS have been analyzed to select the correct example, test items, criteria, and methods. Finally, the guideline has been developed based on international and domestic regulation, through close review of a consultative body composed of academic, industrial, research institute and government experts

  18. Boron Doped diamond films as electron donors in photovoltaics: An X-ray absorption and hard X-ray photoemission study

    Energy Technology Data Exchange (ETDEWEB)

    Kapilashrami, M.; Zegkinoglou, I. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics, University of Wisconsin Madison, Madison, Wisconsin 53706 (United States); Conti, G.; Nemšák, S.; Conlon, C. S.; Fadley, C. S. [Department of Physics, University of California, Davis, California 95616 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Törndahl, T.; Fjällström, V. [Ångström Solar Center, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Lischner, J. [Department of Physics, University of California, Berkeley, California 94720 (United States); Louie, Steven G. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics, University of California, Berkeley, California 94720 (United States); Hamers, R. J.; Zhang, L. [Department of Chemistry, University of Wisconsin Madison, Madison, Wisconsin 53706 (United States); Guo, J.-H. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Himpsel, F. J., E-mail: fhimpsel@wisc.edu [Department of Physics, University of Wisconsin Madison, Madison, Wisconsin 53706 (United States)

    2014-10-14

    Highly boron-doped diamond films are investigated for their potential as transparent electron donors in solar cells. Specifically, the valence band offset between a diamond film (as electron donor) and Cu(In,Ga)Se₂ (CIGS) as light absorber is determined by a combination of soft X-ray absorption spectroscopy and hard X-ray photoelectron spectroscopy, which is more depth-penetrating than standard soft X-ray photoelectron spectroscopy. In addition, a theoretical analysis of the valence band is performed, based on GW quasiparticle band calculations. The valence band offset is found to be small: VBO=VBM{sub CIGS} – VBM{sub diamond}=0.3 eV±0.1 eV at the CIGS/Diamond interface and 0.0 eV±0.1 eV from CIGS to bulk diamond. These results provide a promising starting point for optimizing the band offset by choosing absorber materials with a slightly lower valence band maximum.

  19. Boron Doped diamond films as electron donors in photovoltaics: An X-ray absorption and hard X-ray photoemission study

    International Nuclear Information System (INIS)

    Kapilashrami, M.; Zegkinoglou, I.; Conti, G.; Nemšák, S.; Conlon, C. S.; Fadley, C. S.; Törndahl, T.; Fjällström, V.; Lischner, J.; Louie, Steven G.; Hamers, R. J.; Zhang, L.; Guo, J.-H.; Himpsel, F. J.

    2014-01-01

    Highly boron-doped diamond films are investigated for their potential as transparent electron donors in solar cells. Specifically, the valence band offset between a diamond film (as electron donor) and Cu(In,Ga)Se 2 (CIGS) as light absorber is determined by a combination of soft X-ray absorption spectroscopy and hard X-ray photoelectron spectroscopy, which is more depth-penetrating than standard soft X-ray photoelectron spectroscopy. In addition, a theoretical analysis of the valence band is performed, based on GW quasiparticle band calculations. The valence band offset is found to be small: VBO = VBM CIGS – VBM diamond  = 0.3 eV ± 0.1 eV at the CIGS/Diamond interface and 0.0 eV ± 0.1 eV from CIGS to bulk diamond. These results provide a promising starting point for optimizing the band offset by choosing absorber materials with a slightly lower valence band maximum.

  20. Clinical usefulness of dental X-ray computed tomography for postoperative assessment of secondary alveolar bone grafting

    International Nuclear Information System (INIS)

    Noguchi, Kazuhide; Hamada, Yoshiki; Kondoh, Toshirou; Ishii, Hiroaki; Sonoyama, Tomoo; Kawarada, Takashi; Seto, Kanichi

    2003-01-01

    In this study, the clinical usefulness of dental X-ray computed tomography (CT) for postoperative assessment of secondary alveolar bone grafting was investigated. Nineteen bone-grafted alveolar clefts in 15 patients with cleft lip and palate were studied. All bone bridges were examined by dental three-dimensional (3D)-CT (PSR 9000: Asahi Roentgen, Kyoto, Japan). The postoperative 3D morphology of the bone bridges was easily recognized. Dental 3D-CT images were suggested to be useful for assessment before installation of dental implants in bone bridges. In addition, the status of bone surrounding the installed dental implants and the periodontal space of teeth adjacent to the cleft could be clearly evaluated. In conclusion, dental 3D-CT provides clinically valuable information for the postoperative assessment of secondary alveolar bone grafting. (author)

  1. Sizes of X-ray radiation coherent domains in thin SmS films and their visualization

    Science.gov (United States)

    Sharenkova, N. V.; Kaminskii, V. V.; Petrov, S. N.

    2011-09-01

    The size of X-ray radiation coherent domains (250 ± 20 Å) is determined in a thin polycrystalline SmS film using X-ray diffraction patterns (θ-2θ scanning, DRON-2 diffractometer, Cu K α radiation) and the Selyakov-Scherrer formula with allowance for the effect of microstrains. An image of this film is taken with a transmission electron microscope, and regions with a characteristic size of 240 Å are clearly visible in it. It is concluded that X-ray radiation coherent domains are visualized.

  2. Synchrotron X-ray studies of epitaxial ferroelectric thin films and nanostructures

    Science.gov (United States)

    Klug, Jeffrey A.

    The study of ferroelectric thin films is a field of considerable scientific and technological interest. In this dissertation synchrotron x-ray techniques were applied to examine the effects of lateral confinement and epitaxial strain in ferroelectric thin films and nanostructures. Three materials systems were investigated: laterally confined epitaxial BiFeO3 nanostructures on SrTiO3 (001), ultra-thin commensurate SrTiO 3 films on Si (001), and coherently strained films of BaTiO3 on DyScO3 (110). Epitaxial films of BiFeO3 were deposited by radio frequency magnetron sputtering on SrRuO3 coated SrTiO 3 (001) substrates. Laterally confined nanostructures were fabricated using focused ion-beam processing and subsequently characterized with focused beam x-ray nanodiffraction measurements with unprecedented spatial resolution. Results from a series of rectangular nanostructures with lateral dimensions between 500 nm and 1 mum and a comparably-sized region of the unpatterned BiFeO3 film revealed qualitatively similar distributions of local strain and lattice rotation with a 2-3 times larger magnitude of variation observed in those of the nanostructures compared to the unpatterned film. This indicates that lateral confinement leads to enhanced variation in the local strain and lattice rotation fields in epitaxial BiFeO3 nanostructures. A commensurate 2 nm thick film of SrTiO3 on Si was characterized by the x-ray standing wave (XSW) technique to determine the Sr and Ti cation positions in the strained unit cell in order to verify strain-induced ferroelectricity in SrTiO3/Si. A Si (004) XSW measurement at 10°C indicated that the average Ti displacement from the midpoint between Sr planes was consistent in magnitude to that predicted by a density functional theory (DFT) calculated ferroelectric structure. The Ti displacement determined from a 35°C measurement better matched a DFT-predicted nonpolar structure. The thin film extension of the XSW technique was employed to

  3. X-ray photoelectron spectroscopy study of excimer laser treated alumina films

    Science.gov (United States)

    Georgiev, D. G.; Kolev, K.; Laude, L. D.; Mednikarov, B.; Starbov, N.

    1998-01-01

    Amorphous alumina layers are deposited on a single crystal Si substrate by a e-gun evaporation technique. These films are then thermally annealed in oxygen to be crystallized and, further, irradiated with an excimer laser beam. At each stage of the film preparation, an x-ray photoelectron spectroscopy analysis is performed at the film surface and in depth, upon ion beam grinding. Results give evidence for the formation of an aluminosilicate upon thermal annealing of the film in oxygen. At the surface itself, this compound is observed to decompose upon excimer laser irradiation at energy densities exceeding 1.75 J/cm2, giving rise to free Si atoms and SiO2, however with complete disappearance of Al atoms. Model photochemical reactions are proposed to explain such transformations.

  4. Dental X-ray exposure and Alzheimer's disease: a hypothetical etiological association.

    Science.gov (United States)

    Rodgers, Caroline C

    2011-07-01

    Despite the fact that Alzheimer's disease was identified more than 100 years ago, its cause remains elusive. Although the chance of developing Alzheimer's disease increases with age, it is not a natural consequence of aging. This article proposes that dental X-rays can damage microglia telomeres - the structures at the end of chromosomes that determine how many times cells divide before they die - causing them to age prematurely. Degenerated microglia lose their neuroprotective properties, resulting in the formation of neurofibrillary tau tangles and consequently, the neuronal death that causes Alzheimer's dementia. The hypothesis that Alzheimer's is caused specifically by microglia telomere damage would explain the delay of one decade or longer between the presence of Alzheimer's brain pathology and symptoms; telomere damage would not cause any change in microglial function, it would just reset the countdown clock so that senescence and apoptosis occurred earlier than they would have without the environmental insult. Once microglia telomere damage causes premature aging and death, the adjacent neurons are deprived of the physical support, maintenance and nourishment they require to survive. This sequence of events would explain why therapies and vaccines that eliminate amyloid plaques have been unsuccessful in stopping dementia. Regardless of whether clearing plaques is beneficial or harmful - which remains a subject of debate - it does not address the failing microglia population. If microglia telomere damage is causing Alzheimer's disease, self-donated bone marrow or dental pulp stem cell transplants could give rise to new microglia populations that would maintain neuronal health while the original resident microglia population died. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Determining surface coverage of ultra-thin gold films from X-ray reflectivity measurements

    International Nuclear Information System (INIS)

    Kossoy, A.; Simakov, D.; Olafsson, S.; Leosson, K.

    2013-01-01

    The paper describes usage of X-ray reflectivity for characterization of surface coverage (i.e. film continuity) of ultra-thin gold films which are widely studied for optical, plasmonic and electronic applications. The demonstrated method is very sensitive and can be applied for layers below 1 nm. It has several advantages over other techniques which are often employed in characterization of ultra-thin metal films, such as optical absorption, Atomic Force Microscopy, Transmission Electron Microscopy or Scanning Electron Microscopy. In contrast to those techniques our method does not require specialized sample preparation and measurement process is insensitive to electrostatic charge and/or presence of surface absorbed water. We validate our results with image processing of Scanning Electron Microscopy images. To ensure precise quantitative analysis of the images we developed a generic local thresholding algorithm which allowed us to treat series of images with various values of surface coverage with similar image processing parameters. - Highlights: • Surface coverage/continuity of ultra-thin Au films (up to 7 nm) was determined. • Results from X-ray reflectivity were verified by scanning electron microscopy. • We developed local thresholding algorithm to treat non-homogeneous image contrast

  6. Comparison of light and x-ray sensitometric responses of double-emulsion films for different processing conditions

    International Nuclear Information System (INIS)

    Blendl, Christian; Buhr, Egbert

    2001-01-01

    The effects of different film processing conditions on light and x-ray sensitometric responses were compared for a variety of double-emulsion x-ray films. The processing conditions were altered by changes of the developer temperature. Three different exposure variants were applied: x-ray sensitometry using two stepped neutral density attenuators between film and screens, simultaneous double-sided light sensitometry, and single-sided light sensitometry. 13 different types of double-emulsion x-ray films were investigated, among them three asymmetric films. In the special case of exposing the asymmetric films with the single-sided light sensitometer, a method was investigated where each side of the film is exposed at different locations and the sum effect is analyzed. From each sensitometric curve shape two parameters, the logarithmic speed (log S) and the average gradient (G), were evaluated. The results of this study can be summarized as follows: (1) Single-sided and double-sided light sensitometers revealed almost equal changes of log S when the processing conditions are altered. Thus, single-sided light sensitometers can serve as a substitute for double-sided light sensitometers provided that suited exposure methods are used and appropriate sensitometric parameters are evaluated. (2) Light sensitometry quantitatively indicated changes of the film processing that affect the x-ray speed. Hence, light sensitometry is a useful method to monitor changes in film processing

  7. Nanostructure and bonding of zirconium diboride thin films studied by X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, David M., E-mail: david.stewart@maine.edu; Meulenberg, Robert W.; Lad, Robert J., E-mail: rjlad@maine.edu

    2015-12-01

    Zirconium diboride (ZrB{sub 2}) is an important ceramic due to its extremely high melting temperature of 3245 °C and metallic electrical conductivity, properties that make it an ideal candidate thin film electrode material for high temperature electronics. In this report, thin films of varying B:Zr ratio ranging from 3–0.67 have been grown by e-beam evaporation from elemental sources. X-ray absorption spectra at the Zr K-edge were measured before and after annealing in ultra-high vacuum for 9 h at 1000 °C. Films with compositions near ZrB{sub 2} stoichiometry show X-ray absorption fine structure that can be well modeled by crystalline ZrB{sub 2} with a small portion of a coexisting tetragonal zirconia (t-ZrO{sub 2}) phase. Films far from stoichiometry show substantial disorder beyond the nearest-neighbor distances, and after vacuum annealing exhibit high levels of oxidation. Contributions to the X-ray absorption fine structure from a pure Zr phase are very small compared to ZrB{sub 2} and t-ZrO{sub 2} phases. The fact that nearly stoichiometric (3 < B:Zr < 1.6) as-deposited amorphous films form the same crystalline ZrB{sub 2} nanostructure after annealing is particularly encouraging for high temperature thin film electronics applications, because it would allow the production of highly stable electrodes with e-beam evaporation without the need of any high temperature heating during film growth. - Highlights: • Zr–B thin films of different compositions were grown at low substrate temperatures. • EXAFS analysis indicates a ZrB{sub 2} crystal structure after vacuum annealing. • The coexistence of crystalline and amorphous Zr–B phases is also observed. • Films with excess Zr readily form t-ZrO{sub 2} during deposition, which coexists with ZrB{sub 2}. • Low temperature synthesis routes are important for technological applications.

  8. Study on the management of the Boohung X-Dol 90 developer and fixing solution for automatic X-ray film processor

    International Nuclear Information System (INIS)

    Hyan, Yong Sil; Kim, Heung Tae; Kwon, Dal Gwan; Choi, Myung Joon; Cheung, Hwan

    1986-01-01

    Recently, Demands of Automatic X-ray film Processors are increasing more and more at University Hospitals and general Hospitals and Private clinics, but various troubles because of incorrect control were found out. Authors have researched to find out the function and Activity of Automatic X-ray film processor for 2 weeks Kodak RPX-OMAT Processor and Sakura GX3000 Processor and Doosan parka 2000 Processor and results obtained were as follows: 1. Automatic X-ray film processor have an advantage to conduct the rapid treatment of X-ray film processing but incorrect handling of developing and fixing agents were brought about a great change in Contrast and Optical density of X-ray film pictures. 2. About 300 X-ray film could be finished by same developing and fixing solution without exchanging any other solutions in each Automatic X-ray film processor

  9. [Value of chest x-ray films in the diagnosis of congenital heart defects in infants].

    Science.gov (United States)

    Koczyński, A

    1982-01-01

    The respiratory distress and suspicion of the heart defects in newborns and infants is indicated by x-ray chest examinations. The right interpretation of the x-ray pictures is very important but it must be followed by other diagnostic procedures. In every child it is possible to take the linear measurements of the great vessels and arteries in parahilar lung areas as well as the heart and chest in two dimensions from x-ray plain films. The measurements let to establish the indices: cardio-thoracic (ICP), vasculo-cardiac (IVC) and sagittal one (IS), which play important role in radiological evaluation of the chest. It results from the investigated material, that the evaluation of the pulmonary vascular pattern and the indices particularly facilitate the diagnosis of heart deformities coexisting with higher blood flow in pulmonary circulation. Nevertheless the measurements and the indices play the relative role in establishing of the final opinion about the chest and should be considered together with clinical and cardiological data.

  10. Use of fluorescent-metal intensifying screens with RT-type films for X-ray radiography using pulse devices

    International Nuclear Information System (INIS)

    Morgovskij, L.Ya.; Khakim'yanov, R.R.

    1985-01-01

    A study was made on characteristics of combination of fluorescent-metal Kyokko SMP-308 (Japan) and RCF (Agfa-Gevert) screens with domestic X-ray RT-1, RT-2, RT-5 films. Pulse X-ray MIRA-3D and NORA devices at 200 kV voltage amplitude in X-ray tube were used as radiation source. Testing was conducted for steel samples of 5-40 mm thickness. Comparative exposures for various film combinations with fluorescent-metal screens, fluorescent VP-2 screens and lead foils of 27 μm thickness were determined at that. It is shown that fluorescent-metal screens can be successfully applied with domestic X-ray technical films. They enable to decrease exposure by one order with insignificant deterioration of sensitivity. It is important for testing of pipeline welds

  11. Development of a digital panoramic X-ray imaging system of adaptive image layers for dental applications

    International Nuclear Information System (INIS)

    Choi, S.I.; Park, Y.O.; Cho, H.S.; Oh, J.E.; Cho, H.M.; Hong, D.K.; Lee, M.S.; Yang, Y.J.; Je, U.K.; Kim, D.S.; Lee, H.K.

    2011-01-01

    As a continuation of our digital radiographic sensor R and D, we have developed a prototyped digital panoramic X-ray imaging system for dental applications. The imaging system consists of a slit-collimated X-ray generator with a 0.4 mm focal spot size and a 3.5 mm Al filtration, a linear-array typed CMOS imager with a 48x48 μm 2 pixel size and a 128 (in the scan direction)x3072 (in the vertical direction) pixel format, a series of microstep motors for the precise motion control of the imaging system, and the designed sequences for the motion control and pixel readout required to make a specific plane of interest (POI) to be focused. With the several test phantoms we designed, we obtained useful digital panoramic X-ray images by moving the X-ray generator and the CMOS imager along a continuously sliding rotational center. In this study, we demonstrated that the prototype system can be applicable to any shaped POI or multi-POIs simultaneously to be focused, provided that adequate sequences for motion control and pixel readout are designed. We expect that the imaging system will be useful for our ongoing applications of dental panoramic radiography and nondestructive testing.

  12. About some practical aspects of X-ray diffraction : From powder to thin film

    Energy Technology Data Exchange (ETDEWEB)

    Valvoda, V [Charles Univ. Prague (Czech Republic). Faculty of Mathematics and Physics

    1996-09-01

    Structure of thin films can be amorphous, polycrystalline or epitaxial, and the films can be prepared as a single layer films, multilayers or as graded films. A complete structure analysis of thin films by means of X-ray diffraction (XRD) usually needs more than one diffraction geometry to be used. Their principles, advantages and disadvantages will be shortly described, especially with respect to their different sampling depth and different response to orientation of diffracting crystallographic planes. Main differences in structure of thin films with respect to powder samples are given by a singular direction of their growth, by their adhesion to a substrate and often also by a simultaneous bombardment by atomic species during the growth. It means that a thermodynamically unstable atomic structures can be found too. These special features of growth of thin polycrystalline films are reflected in often found strong preferred orientation of grains and in residual stresses conserved in the films. The methods of structure analysis of thin films by XRD will be compared with other techniques which can supply structure images on different scales.

  13. The calibration of photographic and spectroscopic films: 1: A microscopic analysis of IIaO films. 2: The effects of agitation and soaking on IIaO films. 3: The effects of electric field on IIaO films. 4: The effects of X-ray radiation on IIaO films

    Science.gov (United States)

    Hammond, E. C., Jr.; Peters, K.; Boone, K.

    1978-01-01

    The grain structure of the emulsion using both reflected and transmission light was examined along with the effects of soaking. The effect of a static charge by a Tesla-coil, and the effects of airport equipment, and dental X-rays on the film were also analyzed.

  14. Thoracic spine x-ray

    Science.gov (United States)

    Vertebral radiography; X-ray - spine; Thoracic x-ray; Spine x-ray; Thoracic spine films; Back films ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  15. Element selective X-ray magnetic circular and linear dichroisms in ferrimagnetic yttrium iron garnet films

    Energy Technology Data Exchange (ETDEWEB)

    Rogalev, A. [European Synchrotron Radiation Facility (ESRF), B.P. 220, F-38043 Grenoble Cedex (France); Goulon, J. [European Synchrotron Radiation Facility (ESRF), B.P. 220, F-38043 Grenoble Cedex (France)], E-mail: goulon@esrf.fr; Wilhelm, F. [European Synchrotron Radiation Facility (ESRF), B.P. 220, F-38043 Grenoble Cedex (France); Brouder, Ch. [Institut de Mineralogie et de Physique des Milieux Condenses, UMR-CNRS 7590, Universite Paris VI-VII, 4 place Jussieu, F-75252 Paris Cedex 05 (France); Yaresko, A. [Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart (Germany); Ben Youssef, J.; Indenbom, M.V. [Laboratoire de Magnetisme de Bretagne, CNRS FRE 2697, UFR Sciences et Techniques, F-29328 Brest Cedex (France)

    2009-12-15

    X-ray magnetic circular dichroism (XMCD) was used to probe the existence of induced magnetic moments in yttrium iron garnet (YIG) films in which yttrium is partly substituted with lanthanum, lutetium or bismuth. Spin polarization of the 4d states of yttrium and of the 5d states of lanthanum or lutetium was clearly demonstrated. Angular momentum resolved d-DOS of yttrium and lanthanun was shown to be split by the crystal field, the two resolved substructures having opposite magnetic polarization. The existence of a weak orbital moment involving the 6p states of bismuth was definitely established with the detection of a small XMCD signal at the Bi M{sub 1}-edge. Difference spectra also enhanced the visibility of subtle changes in the Fe K-edge XMCD spectra of YIG and {l_brace}Y, Bi{r_brace}IG films. Weak natural X-ray linear dichroism signatures were systematically observed with all iron garnet films and with a bulk YIG single crystal cut parallel to the (1 1 1) plane: this proved that, at room temperature, the crystal cannot satisfy all requirements of perfect cubic symmetry (space group: Ia3-bar d), crystal distortions preserving at best trigonal symmetry (R3-bar or R3m). For the first time, a very weak X-ray magnetic linear dichroism (XMLD) was also measured in the iron K-edge pre-peak of YIG and revealed the presence of a tiny electric quadrupole moment in the ground-state charge distribution of iron atoms. Band-structure calculations carried out with fully relativistic LMTO-LSDA methods support our interpretation that ferrimagnetically coupled spins at the iron sites induce a spin polarization of the yttrium d-DOS and reproduce the observed crystal field splitting of the XMCD signal.

  16. Element selective X-ray magnetic circular and linear dichroisms in ferrimagnetic yttrium iron garnet films

    International Nuclear Information System (INIS)

    Rogalev, A.; Goulon, J.; Wilhelm, F.; Brouder, Ch.; Yaresko, A.; Ben Youssef, J.; Indenbom, M.V.

    2009-01-01

    X-ray magnetic circular dichroism (XMCD) was used to probe the existence of induced magnetic moments in yttrium iron garnet (YIG) films in which yttrium is partly substituted with lanthanum, lutetium or bismuth. Spin polarization of the 4d states of yttrium and of the 5d states of lanthanum or lutetium was clearly demonstrated. Angular momentum resolved d-DOS of yttrium and lanthanun was shown to be split by the crystal field, the two resolved substructures having opposite magnetic polarization. The existence of a weak orbital moment involving the 6p states of bismuth was definitely established with the detection of a small XMCD signal at the Bi M 1 -edge. Difference spectra also enhanced the visibility of subtle changes in the Fe K-edge XMCD spectra of YIG and {Y, Bi}IG films. Weak natural X-ray linear dichroism signatures were systematically observed with all iron garnet films and with a bulk YIG single crystal cut parallel to the (1 1 1) plane: this proved that, at room temperature, the crystal cannot satisfy all requirements of perfect cubic symmetry (space group: Ia3-bar d), crystal distortions preserving at best trigonal symmetry (R3-bar or R3m). For the first time, a very weak X-ray magnetic linear dichroism (XMLD) was also measured in the iron K-edge pre-peak of YIG and revealed the presence of a tiny electric quadrupole moment in the ground-state charge distribution of iron atoms. Band-structure calculations carried out with fully relativistic LMTO-LSDA methods support our interpretation that ferrimagnetically coupled spins at the iron sites induce a spin polarization of the yttrium d-DOS and reproduce the observed crystal field splitting of the XMCD signal.

  17. Mechanical design of thin-film diamond crystal mounting apparatus for coherence preservation hard x-ray optics

    International Nuclear Information System (INIS)

    Shu, Deming; Shvyd’ko, Yuri V.; Stoupin, Stanislav; Kim, Kwang-Je

    2016-01-01

    A new thin-film diamond crystal mounting apparatus has been designed at the Advanced Photon Source (APS) for coherence preservation hard x-ray optics with optimized thermal contact and minimized crystal strain. This novel mechanical design can be applied to new development in the field of: x-ray optics cavities for hard x-ray free-electron laser oscillators (XFELOs), self-seeding monochromators for hard x-ray free-electron laser (XFEL) with high average thermal loading, high heat load diamond crystal monochromators and beam-sharing/beam-split-and-delay devices for XFEL facilities and future upgraded high-brightness coherent x-ray source in the MBA lattice configuration at the APS.

  18. Mechanical design of thin-film diamond crystal mounting apparatus for coherence preservation hard x-ray optics

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Deming, E-mail: shu@aps.anl.gov; Shvyd’ko, Yuri V.; Stoupin, Stanislav; Kim, Kwang-Je [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, U.S.A (United States)

    2016-07-27

    A new thin-film diamond crystal mounting apparatus has been designed at the Advanced Photon Source (APS) for coherence preservation hard x-ray optics with optimized thermal contact and minimized crystal strain. This novel mechanical design can be applied to new development in the field of: x-ray optics cavities for hard x-ray free-electron laser oscillators (XFELOs), self-seeding monochromators for hard x-ray free-electron laser (XFEL) with high average thermal loading, high heat load diamond crystal monochromators and beam-sharing/beam-split-and-delay devices for XFEL facilities and future upgraded high-brightness coherent x-ray source in the MBA lattice configuration at the APS.

  19. Comparative investigations of high resolution scanning systems for digitising X-ray films

    International Nuclear Information System (INIS)

    Wessel, H.; Rose, P.

    1992-01-01

    The visual or computer-aided evaluation of digitised X-ray films in non-destructive material testing requires highly sensitive scanning systems. They must be able to resolve differences in blackening and convert them into digital data without loss, if possible. Only in this way is the detection of the finest cracks in weld seams or contraction in areas of great sudden changes in blackening of cast parts guaranteed. In the context of this work, measurements were carried out which describe the reproduction properties of different scanning systems. After a short explanation of the different scanning systems, the results of the measurements are shown and evaluated. (orig.) [de

  20. Characterization of thermally evaporated lead iodide films aimed for the detection of X-rays

    International Nuclear Information System (INIS)

    Caldeira Filho, A.M.; Mulato, M.

    2011-01-01

    Some semiconductor materials such as lead iodide (PbI 2 ) have applications in the detection of ionizing radiation at room temperature using the direct detection method. In this work we investigate lead iodide films deposited by thermal evaporation. The morphology, structure, and electric properties were investigated as a function of deposition height, i.e. the distance between evaporation-boat and substrates. The results show a morphology of vertical leaves and X-ray diffraction shows just one preferential orientation along the direction 110. Energy dispersive spectroscopy reveals that the films are not stoichiometric, with excess iodine atoms. Electrical resistivity of about 10 8 Ω cm was measured. This is smaller than for the bulk due to structural defects. The values of activation energy for electric transport increase from 0.52 up to 1.1 eV with decreasing deposition height, what indicates that the best film is the one deposited at the shortest distance. Exposure under X-ray mammographic energy shows a linear behavior up to 500 mR. No variation in sensibility was observed between 22 and 30 kVp.

  1. Setup for in situ X-ray diffraction studies of thin film growth by magnetron sputtering

    CERN Document Server

    Ellmer, K; Weiss, V; Rossner, H

    2001-01-01

    A novel method is described for the in situ-investigation of nucleation and growth of thin films during magnetron sputtering. Energy dispersive X-ray diffraction with synchrotron light is used for the structural analysis during film growth. An in situ-magnetron sputtering chamber was constructed and installed at a synchrotron radiation beam line with a bending magnet. The white synchrotron light (1-70 keV) passes the sputtering chamber through Kapton windows and hits one of the substrates on a four-fold sample holder. The diffracted beam, observed under a fixed diffraction angle between 3 deg. and 10 deg., is energy analyzed by a high purity Ge-detector. The in situ-EDXRD setup is demonstrated for the growth of tin-doped indium oxide (ITO) films prepared by reactive magnetron sputtering from a metallic target.

  2. Improved analytical formulas for x-ray and neutron reflection from surface films

    International Nuclear Information System (INIS)

    Zhou, X.; Chen, S.; Felcher, G.P.

    1992-01-01

    A general and exact expression for x-ray and neutron reflectance and transmittance is given in terms of an integral of the real-space scattering-length-density profile fluctuation of the film, with respect to an arbitrary constant reference density level, over the wave function inside the film. Various special cases and approximations are then derived from this exact form by suitable approximations of the wave function. In particular, two practical approximate formulas are derived which are improvement over the corresponding distorted-wave Born approximations. One is for an arbitrary film deposited on a known substrate and the other for a free liquid surface. Numerical results are used to illustrate the accuracy of these formulas

  3. Quantitative orientational characterization if low - density polyethylene blow films by x-ray and birefringence

    International Nuclear Information System (INIS)

    Taheri Qazvini, N.; Mohammadi, N.; Ghaffarian, R.; Assempour, H.; Haghighatkish, M.

    2002-01-01

    The effect of two important parameters of film blowing processes, i.e., take-up ration and blow-up ratio, on the overall orientation of low-density blown films have been investigated using birefringence measurements. Furthermore, by combining x-ray diffraction pole figure analysis and birefringence, the White and Spruiell biaxial orientation functions have been determined for aforementioned sample. Within the range of processing condition studied, increasing take-up ratio, increases orientation in both machine and transverse direction. Upon increasing blow-up ratio, orientation in the transverse direction increases and the overall orientation state approaches to equal biaxial one. Characterization of the crystalline regions by pole figure analysis reveals that a and b crystallographic axes preferentially orientate in the film plane and the direction normal to it, respectively. The amorphous regions do not have any preferential orientation

  4. The quality of X-ray film processing. Report of a sensitometric field study

    International Nuclear Information System (INIS)

    Stargardt, A.; Buehler, G.

    1985-01-01

    One hundred and eighty of about 800 X-ray film processors used in the GDR were checked sensitometrically. Sensitometric control strips, pre-exposed at a certain level, were mailed, processed and re-mailed; fog, the density of a medium-density step and a density difference were then determined. Reference data were obtained by processing exactly according to the recommendations of the film manufacturer; the mean of fog measurements equals the reference value. Seven per cent of processors produced fog which was unacceptable. The mean of the medium density measurements was 10% below the reference value. Five per cent of all processors operated at unacceptably high, and 16% at unacceptably low, density. Since failures in processing are commonly compensated for by changing radiation doses, consequences for radiation exposure are obvious. Analysis of data on operating parameters supplied by the users identified the disproportion between developer replenisher rate and film load as the main reason for this unsatisfactory situation. (author)

  5. Structural anisotropy in amorphous SnO2 film probed by X-ray absorption spectroscopy

    Science.gov (United States)

    Zhu, Q.; Ma, Q.; Buchholz, D. B.; Chang, R. P. H.; Bedzyk, M. J.; Mason, T. O.

    2013-07-01

    Polarization-dependent X-ray absorption measurements reveal the existence of structural anisotropy in amorphous (a-) SnO2 film. The anisotropy is readily seen for the second neighbor interaction whose magnitude differs along three measured directions. The differences can be well accounted for by 10%-20% variation in the Debye-Waller factor. Instead of a single Gaussian distribution found in crystalline SnO2, the Sn-O bond distribution is bimodal in a-SnO2 whose separation shows a weak angular dependence. The oxygen vacancies, existing in the a-SnO2 film in the order of 1021 cm-3, distribute preferentially along the film surface direction.

  6. A device for checking the speeds and quality of X-ray films and efficiency of film processors

    International Nuclear Information System (INIS)

    Crooks, H.E.

    1980-01-01

    In order to carry out quality assurance tests of X-ray films, screens and processors, a standard exposure source of utmost reliability is desirable. The performance of apparatus containing yellow-green light emitting radioactive tritium activated phosphor, known as Betalight, is described. Over a period of 2 1/2 years, variations in film speeds up to +- 20% from nominally the same types of film have been observed. Additionally, substandard developer has been easily identified with the use of this device. The device is cheap and easy to manufacture, accurate and simple to use. (U.K.)

  7. Ordering phenomena in FeCo-films and Fe/Cr-multilayers: an X-ray and neutron scattering study

    Energy Technology Data Exchange (ETDEWEB)

    Nickel, B.

    2001-07-01

    The following topics are covered: critical phenomena in thin films, critical adsorption, finite size scaling, FeCo Ising model, kinematical scattering theory for thin films, FeCo thin films, growth and characterisation of single crystal FeCo thin films, X-ray study of ordering in FeCo films, antiferromagnetic coupling in Fe/Cr multilayers, neutron scattering on Fe/Cr multilayers (WL)

  8. High resolution hard X-ray photoemission using synchrotron radiation as an essential tool for characterization of thin solid films

    International Nuclear Information System (INIS)

    Kim, J.J.; Ikenaga, E.; Kobata, M.; Takeuchi, A.; Awaji, M.; Makino, H.; Chen, P.P.; Yamamoto, A.; Matsuoka, T.; Miwa, D.; Nishino, Y.; Yamamoto, T.; Yao, T.; Kobayashi, K.

    2006-01-01

    Recently, we have shown that hard X-ray photoemission spectroscopy using undulator X-rays at SPring-8 is quite feasible with both high resolution and high throughput. Here we report an application of hard X-ray photoemission spectroscopy to the characterization of electronic and chemical states of thin solid films, for which conventional PES is not applicable. As a typical example, we focus on the problem of the scatter in the reported band-gap values for InN. We show that oxygen incorporation into the InN film strongly modifies the valence and plays a crucial role in the band gap problem. The present results demonstrate the powerful applicability of high resolution photoemission spectroscopy with hard X-rays from a synchrotron source

  9. X-ray beam monitor made by thin-film CVD single-crystal diamond.

    Science.gov (United States)

    Marinelli, Marco; Milani, E; Prestopino, G; Verona, C; Verona-Rinati, G; Angelone, M; Pillon, M; Kachkanov, V; Tartoni, N; Benetti, M; Cannatà, D; Di Pietrantonio, F

    2012-11-01

    A novel beam position monitor, operated at zero bias voltage, based on high-quality chemical-vapor-deposition single-crystal Schottky diamond for use under intense synchrotron X-ray beams was fabricated and tested. The total thickness of the diamond thin-film beam monitor is about 60 µm. The diamond beam monitor was inserted in the B16 beamline of the Diamond Light Source synchrotron in Harwell (UK). The device was characterized under monochromatic high-flux X-ray beams from 6 to 20 keV and a micro-focused 10 keV beam with a spot size of approximately 2 µm × 3 µm square. Time response, linearity and position sensitivity were investigated. Device response uniformity was measured by a raster scan of the diamond surface with the micro-focused beam. Transmissivity and spectral responsivity versus beam energy were also measured, showing excellent performance of the new thin-film single-crystal diamond beam monitor.

  10. Capability of X-ray diffraction for the study of microstructure of metastable thin films

    Directory of Open Access Journals (Sweden)

    David Rafaja

    2014-11-01

    Full Text Available Metastable phases are often used to design materials with outstanding properties, which cannot be achieved with thermodynamically stable compounds. In many cases, the metastable phases are employed as precursors for controlled formation of nanocomposites. This contribution shows how the microstructure of crystalline metastable phases and the formation of nanocomposites can be concluded from X-ray diffraction experiments by taking advantage of the high sensitivity of X-ray diffraction to macroscopic and microscopic lattice deformations and to the dependence of the lattice deformations on the crystallographic direction. The lattice deformations were determined from the positions and from the widths of the diffraction lines, the dependence of the lattice deformations on the crystallographic direction from the anisotropy of the line shift and the line broadening. As an example of the metastable system, the supersaturated solid solution of titanium nitride and aluminium nitride was investigated, which was prepared in the form of thin films by using cathodic arc evaporation of titanium and aluminium in a nitrogen atmosphere. The microstructure of the (Ti,AlN samples under study was tailored by modifying the [Al]/[Ti] ratio in the thin films and the surface mobility of the deposited species.

  11. A search for strain gradients in gold thin films on substrates using x-ray diffraction

    International Nuclear Information System (INIS)

    Leung, O. S.; Munkholm, A.; Brennan, S.; Nix, W. D.

    2000-01-01

    The high strengths of gold thin films on silicon substrates have been studied with particular reference to the possible effect of strain gradients. Wafer curvature/thermal cycling measurements have been used to study the strengths of unpassivated, oxide-free gold films ranging in thickness from 0.1 to 2.5 μm. Films thinner than about 1 μm in thickness appear to be weakened by diffusional relaxation effects near the free surface and are not good candidates for the study of strain gradient plasticity. Our search for plastically induced strain gradients was thus limited to thicker films with correspondingly larger grain sizes. Three related x-ray diffraction techniques have been used to investigate the elastic strains in these films. The standard d hkl vs sin2 Ψ technique has been used to find the average strain through the thickness of the films. The results are consistent with wafer curvature measurements. We have also measured a number of d hkl 's as a function of penetration depth to construct depth-dependent d hkl vs sin2 Ψ plots. These data show that the residual elastic strain is essentially independent of depth in the film. Finally, a new technique for sample rotation has been used to measure the d hkl 's for a fixed set of grains in the film as a function of penetration depth. Again, no detectable gradient in strain has been observed. These results show that the high strengths of unpassivated gold films relative to the strength of bulk gold cannot be rationalized on the basis of strain gradients through the film thickness. However, a sharp gradient in strain close to the film substrate interface cannot be ruled out. (c) 2000 American Institute of Physics

  12. H and D curves of screen--film systems: factors affecting their dependence on x-ray energy

    International Nuclear Information System (INIS)

    Vyborny, C.J.

    1979-01-01

    The sensitometric properties of radiographic screen--film systems are investigated with regard to their dependence on x-ray energy. Sensitometric measurements and a heuristic model for density formation are used to show that variation in the relative amount of light emitted by front and back screens may be the most important factor influencing the change in system H and D curves with x-ray energy

  13. Particle Induced X-ray Emission (PIXE) Approach for the Quantification of Thin Al Films

    International Nuclear Information System (INIS)

    Younes, G; Zahraman, K; Nsouli, B; Soueidan, M; Ferro, G

    2008-01-01

    Particle Induced X-ray Emission (PIXE) has been used as a fast and non-destructive technique for sensitive characterization of ultra thin Al films deposited by evaporation onto Si substrate. In this work the PIXE technique was optimized, using proton beam at different energies and different angles of incidence, for the characterization of ultra thin Al films (few nanometers) deposited onto Si substrate. The PIXE results showed that a proton beam of 300 keV under tilting angle of 80 degree permits an accurate determination of Al with high sensitivity within few minutes of acquisition time and a LOD of less than 0.2 nm. The LOD versus energy and tilting angle will be presented and discussed. (author)

  14. Local Plasticity of Al Thin Films as Revealed by X-Ray Microdiffraction

    Science.gov (United States)

    Spolenak, R.; Brown, W. L.; Tamura, N.; MacDowell, A. A.; Celestre, R. S.; Padmore, H. A.; Valek, B.; Bravman, J. C.; Marieb, T.; Fujimoto, H.; Batterman, B. W.; Patel, J. R.

    2003-03-01

    Grain-to-grain interactions dominate the plasticity of Al thin films and establish effective length scales smaller than the grain size. We have measured large strain distributions and their changes under plastic strain in 1.5-μm-thick Al0.5%Cu films using a 0.8-μm-diameter white x-ray probe at the Advanced Light Source. Strain distributions arise not only from the distribution of grain sizes and orientation, but also from the differences in grain shape and from stress environment. Multiple active glide plane domains have been found within single grains. Large grains behave like multiple smaller grains even before a dislocation substructure can evolve.

  15. Some properties of six different types of dental x-ray unit

    NARCIS (Netherlands)

    Trouerbach, W.Th.; Aken, J. van

    1965-01-01

    Forty-four x-ray machines were tested for reliability of timer and for output. A distinction was made between different types of errors, and large differences between these categories of errors were found.

  16. Low Dose X-Ray Sources and High Quantum Efficiency Sensors: The Next Challenge in Dental Digital Imaging?

    Directory of Open Access Journals (Sweden)

    Arnav R. Mistry

    2014-01-01

    Full Text Available Objective(s. The major challenge encountered to decrease the milliamperes (mA level in X-ray imaging systems is the quantum noise phenomena. This investigation evaluated dose exposure and image resolution of a low dose X-ray imaging (LDXI prototype comprising a low mA X-ray source and a novel microlens-based sensor relative to current imaging technologies. Study Design. A LDXI in static (group 1 and dynamic (group 2 modes was compared to medical fluoroscopy (group 3, digital intraoral radiography (group 4, and CBCT scan (group 5 using a dental phantom. Results. The Mann-Whitney test showed no statistical significance (α=0.01 in dose exposure between groups 1 and 3 and 1 and 4 and timing exposure (seconds between groups 1 and 5 and 2 and 3. Image resolution test showed group 1 > group 4 > group 2 > group 3 > group 5. Conclusions. The LDXI proved the concept for obtaining a high definition image resolution for static and dynamic radiography at lower or similar dose exposure and smaller pixel size, respectively, when compared to current imaging technologies. Lower mA at the X-ray source and high QE at the detector level principles with microlens could be applied to current imaging technologies to considerably reduce dose exposure without compromising image resolution in the near future.

  17. Theory of X-ray microcomputed tomography in dental research: application for the caries research

    OpenAIRE

    Young-Seok Park; Kwang-Hak Bae; Juhea Chang; Won-Jun Shon

    2011-01-01

    Caries remains prevalent throughout modern society and is the main disease in the field of dentistry. Although studies of this disease have used diverse methodology, recently, X-ray microtomography has gained popularity as a non-destructive, 3-dimensional (3D) analytical technique, and has several advantages over the conventional methods. According to X-ray source, it is classified as monochromatic or polychromatic with the latter being more widely used due to the high cost of the monochromat...

  18. Film-based X-ray tomography combined with digital image processing: investigation of an ancient pattern-welded sword

    International Nuclear Information System (INIS)

    Lindegaard-Andersen, A.; Vedel, T.; Jeppesen, L.; Gottlieb, B.

    1988-01-01

    Film-based X-ray tomography and digital image processing have been used to investigate an inhomogeneous object of non-circular cross-section. The feasibility of using digital image processing to compensate for the poor contrast resolution inherent in film-based tomography has been demonstrated. (author)

  19. Exposure to ionizing radiation during dental X-rays is not associated with risk of developing meningioma: a meta-analysis based on seven case-control studies.

    Science.gov (United States)

    Xu, Ping; Luo, Hong; Huang, Guang-Lei; Yin, Xin-Hai; Luo, Si-Yang; Song, Ju-Kun

    2015-01-01

    Many observational studies have found that exposure to dental X-rays is associated with the risk of development of meningioma. However, these findings are inconsistent. We conducted a meta-analysis to assess the relationship between exposure to dental X-rays and the risk of development of meningioma. The PubMed and EMBASE databases were searched to identify eligible studies. Summary odds ratio (OR) estimates and 95% confidence intervals (95% CIs) were used to compute the risk of meningioma development according to heterogeneity. Subgroup and sensitivity analyses were performed to further explore the potential heterogeneity. Finally, publication bias was assessed. Seven case-control studies involving 6,174 patients and 19,459 controls were included in the meta-analysis. Neither exposure to dental X-rays nor performance of full-mouth panorex X-rays was associated with an increased risk of development of meningioma (overall: OR, 0.97; 95% CI, 0.70-1.32; dental X-rays: OR, 1.05; 95% CI, 0.89-1.25; panorex X-rays: OR, 1.01; 95% CI, 0.76-1.34). However, exposure to bitewing X-rays was associated with a slightly increased risk of development of meningioma (OR, 1.73; 95% CI, 1.28-2.34). Similar results were obtained in the subgroup and sensitivity analyses. Little evidence of publication bias was observed. Based on the currently limited data, there is no association between exposure to dental X-rays and the risk of development of meningioma. However, these results should be cautiously interpreted because of the heterogeneity among studies. Additional large, high-quality clinical trials are needed to evaluate the association between exposure to dental X-rays and the risk of development of meningioma.

  20. Exposure to ionizing radiation during dental X-rays is not associated with risk of developing meningioma: a meta-analysis based on seven case-control studies.

    Directory of Open Access Journals (Sweden)

    Ping Xu

    Full Text Available Many observational studies have found that exposure to dental X-rays is associated with the risk of development of meningioma. However, these findings are inconsistent. We conducted a meta-analysis to assess the relationship between exposure to dental X-rays and the risk of development of meningioma.The PubMed and EMBASE databases were searched to identify eligible studies. Summary odds ratio (OR estimates and 95% confidence intervals (95% CIs were used to compute the risk of meningioma development according to heterogeneity. Subgroup and sensitivity analyses were performed to further explore the potential heterogeneity. Finally, publication bias was assessed.Seven case-control studies involving 6,174 patients and 19,459 controls were included in the meta-analysis. Neither exposure to dental X-rays nor performance of full-mouth panorex X-rays was associated with an increased risk of development of meningioma (overall: OR, 0.97; 95% CI, 0.70-1.32; dental X-rays: OR, 1.05; 95% CI, 0.89-1.25; panorex X-rays: OR, 1.01; 95% CI, 0.76-1.34. However, exposure to bitewing X-rays was associated with a slightly increased risk of development of meningioma (OR, 1.73; 95% CI, 1.28-2.34. Similar results were obtained in the subgroup and sensitivity analyses. Little evidence of publication bias was observed.Based on the currently limited data, there is no association between exposure to dental X-rays and the risk of development of meningioma. However, these results should be cautiously interpreted because of the heterogeneity among studies. Additional large, high-quality clinical trials are needed to evaluate the association between exposure to dental X-rays and the risk of development of meningioma.

  1. Comparative review of computed tomography of the spinal column and conventional x-ray films

    Energy Technology Data Exchange (ETDEWEB)

    Shin, H.; Yamaura, A.; Horie, T.; Makino, H. (Chiba Univ. (Japan). School of Medicine)

    1982-04-01

    Computerized tomography (CT) of the cervical spinal column was carried out in 39 patients using a GE.CT/T or Toshiba TCT60A scanner. There were 22 cervical disk lesions, 4 spinal neoplasms, 5 narrow spinal canals with or without ossification of the posterior longitudinal ligament, 2 syringomyelias, 5 traumas, and one Arnold-Chiari malformation. In all the patients, tomography was done after conventional spinal X-ray studies. The correlation between the CT findings and conventional X-ray films revealed the excellent capability of the CT. The measurement of the midline sagittal diameter of the spinal canal in the patient with the narrowest canal in this series showed 7.4 mm when done by CT and 9.6 mm when done by the conventional plain film at the C/sub 5/ level. To ascertain the precise sagittal diameter of the cord itself, CT myelography is indispensable after the intrathecal injection of metrizamide A; metrizamide CT myelogram is useful in determining the nature of the disease, the risk of and best approach to surgery, and the evaluation after a surgical procedure. Although the range of motion of cervical joints and intervertebral foramen are visible with the conventional films, the size of the spinal tumors, the degree of bony change, and the tumor extension to the paraspinal connective tissue can be precisely demonstrated only by CT. A CT study of the spine is a simple procedure and is less likely to produce complication, even with a metrizamide CT myelogram, though there are certain limitations in the examination.

  2. Structure analysis of InN film using extended X-ray absorption fine structure method

    Energy Technology Data Exchange (ETDEWEB)

    Miyajima, T.; Kobayashi, T.; Hirata, S. [Core Technology Development Center, Core Technology and Network Company, Sony Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa 243-0014 (Japan); Kudo, Y.; Liu, K.L. [Technology Solutions Center, Sony Corporation, 4-16-1 Okata, Atsugi, Kanagawa 243-0021 (Japan); Uruga, T.; Honma, T. [Japan Synchrotron Radiation Research Institute, Mikazuki-cho, Hyogo 679-5198 (Japan); Saito, Y.; Hori, M.; Nanishi, Y. [Department of Photonics, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577 (Japan)

    2002-12-01

    We investigated the local atomic structure around In atoms of MBE-grown InN which has a direct bandgap energy of 0.8 eV, using extended X-ray absorption fine structure (EXAFS) oscillation of In K-edge. The signals from the first-nearest neighbor atoms (N) and second-nearest atoms (In) from In atoms were clearly observed and the atomic bond length of In-N and In-In was estimated to be d{sub In-N}=0.215 nm and d{sub In-In}=0.353 nm, respectively. The In-N bond length of d{sub In-In}=0.353 nm was closed to the a-axis lattice constant of a=0.3536 nm, which was determined using X-ray diffraction measurements. The obtained local atomic structure agreed with the calculated ideal structure. We conclude, therefore, that the InN film with a bandgap energy of 0.8 eV has a high structural symmetry in the range of a few A around In atoms. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  3. Structure analysis of InN film using extended X-ray absorption fine structure method

    International Nuclear Information System (INIS)

    Miyajima, T.; Kobayashi, T.; Hirata, S.; Kudo, Y.; Liu, K.L.; Uruga, T.; Honma, T.; Saito, Y.; Hori, M.; Nanishi, Y.

    2002-01-01

    We investigated the local atomic structure around In atoms of MBE-grown InN which has a direct bandgap energy of 0.8 eV, using extended X-ray absorption fine structure (EXAFS) oscillation of In K-edge. The signals from the first-nearest neighbor atoms (N) and second-nearest atoms (In) from In atoms were clearly observed and the atomic bond length of In-N and In-In was estimated to be d In-N =0.215 nm and d In-In =0.353 nm, respectively. The In-N bond length of d In-In =0.353 nm was closed to the a-axis lattice constant of a=0.3536 nm, which was determined using X-ray diffraction measurements. The obtained local atomic structure agreed with the calculated ideal structure. We conclude, therefore, that the InN film with a bandgap energy of 0.8 eV has a high structural symmetry in the range of a few A around In atoms. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  4. X-ray photoelectron spectroscopic study of catalyst based zinc oxide thin films

    International Nuclear Information System (INIS)

    Shinde, S.S.; Rajpure, K.Y.

    2011-01-01

    Research highlights: → The two step approach for quantitative XPS analysis of ZnO films has been reported. → Surface composition and chemical states of F and In/ZnO catalysts have been studied. → The chemical shifts and Auger parameter have been investigated. - Abstract: X-ray photoelectron spectroscopy (XPS) is a powerful tool for surface and interface analysis, providing an elemental composition of surfaces and the local chemical environment of adsorbed species. The surface composition and chemical states of the F/ZnO and In/ZnO catalysts deposited using spray technique have been studied by high resolution and high sensitivity X-ray photoelectron spectroscopy. A hybrid multiline method is proposed for quantitative XPS analysis that combines the first principles approach with the experimental determination of overall response function. The chemical shifts of XPS core lines for Zn (2P 3/2 , F 1s and In 3d) and Auger parameter for zinc (β Zn = 2012.6, 2011.48 eV for F/ZnO and In/ZnO, respectively) have been calculated. The results have been used to determine the bond iconicity (0.55).

  5. Evaluation of the effects of high energy X-ray radiation in materials used in dental restorations

    International Nuclear Information System (INIS)

    Maio, Mireia Florencio; Santos, Adimir dos; Fernandes, Marco Antonio Rodrigues

    2011-01-01

    This work studied the behavior of the physical features and chemical composition of materials used in dental restorations (titanium, amalgam, composite resin and glass ionomer cement) which were submitted to x-ray radiation of 6.0 Mega-Volt (MV) of energy produced in a linear accelerator that is used in radiotherapy of head and neck tumors 1 2. The samples were analyzed using a x-ray fluorescence technique by comparing the chemical composition before and after irradiation. In order to check the residual radiation in the samples, measurements of the sample dosimetry were performed with Geiger-Mueller radiation detectors and an ionization chamber. The samples were also analyzed by gamma-ray spectrometry using a hyper-pure Germanium (HPGe) detector. From these tests, we aimed to verify small changes in the composition of the test bodies due to the radiation. (author)

  6. Evaluation of the effects of high energy X-ray radiation in materials used in dental restorations

    Energy Technology Data Exchange (ETDEWEB)

    Maio, Mireia Florencio; Santos, Adimir dos, E-mail: mfmaio@ipen.br, E-mail: asantos@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Fernandes, Marco Antonio Rodrigues, E-mail: marfernandes@fmb.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Departamento de Radioterapia

    2011-07-01

    This work studied the behavior of the physical features and chemical composition of materials used in dental restorations (titanium, amalgam, composite resin and glass ionomer cement) which were submitted to x-ray radiation of 6.0 Mega-Volt (MV) of energy produced in a linear accelerator that is used in radiotherapy of head and neck tumors 1 2. The samples were analyzed using a x-ray fluorescence technique by comparing the chemical composition before and after irradiation. In order to check the residual radiation in the samples, measurements of the sample dosimetry were performed with Geiger-Mueller radiation detectors and an ionization chamber. The samples were also analyzed by gamma-ray spectrometry using a hyper-pure Germanium (HPGe) detector. From these tests, we aimed to verify small changes in the composition of the test bodies due to the radiation. (author)

  7. X-ray absorption study of silicon carbide thin film deposited by pulsed laser deposition

    International Nuclear Information System (INIS)

    Monaco, G.; Suman, M.; Garoli, D.; Pelizzo, M.G.; Nicolosi, P.

    2011-01-01

    Silicon carbide (SiC) is an important material for several applications ranging from electronics to Extreme UltraViolet (EUV) space optics. Crystalline cubic SiC (3C-SiC) has a wide band gap (near 2.4 eV) and it is a promising material to be used in high frequency and high energetic electronic devices. We have deposited, by means of pulsed laser deposition (PLD), different SiC films on sapphire and silicon substrates both at mild (650 o C) and at room temperature. The resulted films have different structures such as: highly oriented polycrystalline, polycrystalline and amorphous which have been studied by means of X-ray absorption spectroscopy (XAS) near the Si L 2,3 edge and the C K edge using PES (photoemission spectroscopy) for the analysis of the valence bands structure and film composition. The samples obtained by PLD have shown different spectra among the grown films, some of them showing typical 3C-SiC absorption structure, but also the presence of some Si-Si and graphitic bonds.

  8. Ultrathin Pt films on Ni(111): Structure determined by surface x-ray diffraction

    International Nuclear Information System (INIS)

    Robach, O.; Isern, H.; Quiros, C.; Ferrer, S.; Steadman, P.; Peters, K. F.

    2003-01-01

    The growth of platinum on a nickel (111) single crystal under ultrahigh vacuum conditions was studied using surface x-ray diffraction on the ID03 beamline of the ESRF. Film thickness ranged from one to eight monoatomic layers (ML). Specular reflectivity was used to determine the growth mode and vertical lattice parameter of the Pt film. A two-dimensional (2D) growth up to 1 ML followed by more 3D growth was found. A small expansion of the Pt vertical lattice parameter was found. The Pt in-plane lattice parameter was measured. Its relaxation was found to be very slow, with a residual contraction of 2.3% in an 8-ML-thick film (with respect to bulk Pt). A Ni crystal truncation rod measured before and after growing 1 ML of Pt revealed the presence of a small amount of pseudomorphic Pt, adsorbed on both fcc and hcp sites. The stacking of the (111) Pt planes was investigated by measuring stacking-sensitive Pt diffraction rods. A strong tendency to stacking reversal was found at room temperature, with an amount of 'reversed' Pt about ten times higher than the amount of Pt with the same stacking as the Ni. An eight-layer Ni film on Pt(111) was also studied for comparison

  9. X-Ray fluorescence of microquantities of hafnium in zirconium by precipitation as thin film

    International Nuclear Information System (INIS)

    Vigoda de Leyt, Dora; Caridi, A.F.; Deibe, Jorge

    1988-01-01

    The importance of Zr and Hf in the nuclear industry represents and increasing need for the development of reliable chemical methods to determine Hf traces in Zr matrix. A precipitation method in amoniacal medium was developed. A thin film is obtained where matrix effects are absent or minimized. Hf in the range of 5-70.10 -9 Kg in a 5.10 -6 Kg Zr matrix was studied. Fluorescence Hf Lα and Hf Lβ X-rays are excited by a W-anode tube 17 kV-25mA and 50kV-25mA. Radiation scattered by the tube was used as internal standard. Bartlett criterion was used for the regression analysis. Determination limit was fixed in 5±4. 10 -9 Kg Hf at a 95 % probability. (Author) [es

  10. On the problem of knee joint articular space in the X-ray film

    International Nuclear Information System (INIS)

    Saure, D.; Emminger, A.; Freyschmidt, J.

    1980-01-01

    Measurements of the width of the intraarticular space were performed in X-ray films of 64 human knee joints (32 patients), taken laterally, and in standing position after 24 hours of rest in bed or after exposure to load for one hour. In more than half of the knee joints, the width of the intraarticular space increased after load. However, the distance between the articular surfaces rarely changed in the same patient in the same sense in the right and left knee joint, respectively medially and laterally. Hence, this method of indirect measurement of the cartilaginous layer is unsuitable, and the question raised in literature regarding the cartilaginous changes under load can be explained as being due to influx of fluid or as an expression of the viso-elastic properties of the articular cartilage. (orig.) 891 MG/orig. 892 MB [de

  11. X-ray fluorescence system for thin film composition analysis during deposition

    International Nuclear Information System (INIS)

    Formica, Sarah P.; Lee, Susanne M.

    2005-01-01

    A fast-response-time X-ray fluorescence (XRF) system was designed with a monolithic polycapillary focusing optic for in situ composition profiling during materials deposition. The polycapillary optic produced 10 5 times more intensity at the sample than a pinhole, allowing the detector placement to be outside most deposition chambers. The resultant XRF signals were so strong that measurement times were comparable to monolayer growth times. XRF line scans from Ge 1-x Sn x thin films were used to map Sn concentration versus surface position with a 10 μm resolution. The extrapolated instrumental detection limit using a 20 W Cu source was 10 12 atoms (ng). XRF from a 100-nm ion-implanted Ge 0.72 Sn 0.28 sample demonstrated the system's ability to monitor initial growth stages during deposition

  12. X-ray magnetic absorption in Fe-Tb amorphous thin films

    CERN Document Server

    Kim, Chan Wook; Watanabe, Yasuhiro

    1999-01-01

    In order to investigate the magnetic structure of Fe-Tb amorphous thin films, we have performed magnetic circular dichroism (MCD) measurements by using the circularly polarized X-ray at the Fe K- and the Tb L2,3-edges in Fe sub 8 sub 8 Tb sub 1 sub 2 , Fe sub 8 sub 0 Tb sub 2 sub 0 , and Fe sub 6 sub 2 Tb sub 3 sub 8. In all samples, the spin-dependent absorption effects, DELTA mu t, were observed. Also, elementary information was obtained on the spin polarizations of the p- and the d-projected electrons lying in the unoccupied states near the Fermi levels in the samples.

  13. The behaviour of the pulmonary vessels on X-ray films of children with asthma bronchiale

    International Nuclear Information System (INIS)

    Hegenbarth, R.; Toeroek, M.; Medizinische Hochschule Hannover

    1986-01-01

    On X-ray films of 51 children with asthma bronchiale the authors determined the vascular diameter of the right ascending pulmonary artery, the right vein of the upper lobe, and the peripheral vessels in the upper and lower pulmonary fields at an exactly defined distance from the hilus point, and compared these data with those of a control group of 143 healthy children. During the asthma attack the width of the right descending pulmonary artery and of the vein of the upper lobe corresponded to the values of the control group, whereas the vascular diameters in the upper and lower fields were clearly narrowed. Moreover, in most of the asthmatic children the authors found arc-shaped vessels and irregularly occluded vessels in the periphery of the lungs. (orig.) [de

  14. In-Situ Synchrotron X-ray Study of the Phase and Texture Evolution of Ceria and Superconductor Films Deposited by Chemical Solution Method

    DEFF Research Database (Denmark)

    Yue, Zhao; Grivel, Jean-Claude; He, Dong

    2012-01-01

    In situ synchrotron x-ray diffraction is used to study the phase and texture formation of ceria based films and superconductor films deposited by the chemical solution method on technical substrates. Combined analysis using in situ synchrotron x-ray diffraction, thermogravimetry/differential ther......In situ synchrotron x-ray diffraction is used to study the phase and texture formation of ceria based films and superconductor films deposited by the chemical solution method on technical substrates. Combined analysis using in situ synchrotron x-ray diffraction, thermogravimetry...

  15. Film replacement by digital x-ray detectors - the correct procedure and equipment

    International Nuclear Information System (INIS)

    Ewert, U.; Zscherpel, U.; Bavendiek, K.

    2004-01-01

    New digital detectors were developed for medical applications, which have the potential to substitute the X-ray film and revolutionise the radiological technique. Digital Detector Arrays (DDA: Flat Panel Detectors, Line Detectors) and Imaging Plates (Computed Radiography) allow a fast detection of radiographic images in a shorter time and with higher dynamic than film applications. Companies report about a reduction of exposure time down to 5 - 25% in comparison to NDT film exposures. This provides together with the reduction of consumables economical (and also ecological) benefits and short amortisation periods. But this does not always provide the same image quality as NDT film. The requirements of the European and USA standards for film radiography are analysed to derive correct requirements for the digital image quality and procedures for prediction and measurement of image quality. Basically the USA standards seem to be more tolerant for these new innovative technologies. New standard proposals use signal/noise ratio and unsharpness as dominant parameters for image quality. Specialised measurement procedures are described. The properties of the new detectors can be controlled by electronics and exposure conditions. New names appear in literature like 'direct radiography' and 'film replacement techniques'. The basic advantage of the new digital techniques is the possibility to use numeric procedures for image interpretation. Industrial radiology can be optimised for crack detection as well as for analysis of flaw depth and shape measurement. Automated flaw detection, measurement of part dimensions and detection of completeness are used for serial part inspection devices. Parallel to the development of DDA's, an extraordinary increase of Computed Tomography (CT) applications can be observed. (author)

  16. Dose and absorption spectra response of EBT2 Gafchromic film to high energy X-rays

    International Nuclear Information System (INIS)

    Butson, M.J.; Cheung, T.; Yu, P.K.N.; Alnawaf, H.

    2009-01-01

    Full text: With new advancements in radiochromic film designs and sensitivity to suit different niche applications, EBT2 is the latest offering for the megavoltage radiotherapy market. New construction specifications including different physical construction and the use of a yellow coloured dye has provided the next generation radiochromic film for therapy applications. The film utilises the same active chemical for radiation measurement as its predecessor, EBT Gafchromic. Measurements have been performed using photo spectrometers to analyse the absorption spectra properties of this new EBT2 Gafchromic, radiochromic film. Results have shown that whilst the physical coloration or absorption spectra of the film, which turns yellow to green as compared to EBT film, (clear to blue) is significantly different due to the added yellow dye, the net change in absorption spectra properties for EBT2 are similar to the original EBT film. Absorption peaks are still located at 636 n m and 585 n m positions. A net optical density change of 0.590 ± 0.020 (2SD) for a 1 Gy radiation absorbed dose using 6 MV x-rays when measured at the 636 n m absorption peak was found. This is compared to 0.602 ± 0.025 (2SD) for the original EBT film (2005 Batch) and 0.557 ± 0.027 (2009 Batch) at the same absorption peak. The yellow dye and the new coating material produce a significantly different visible absorption spectra results for the EBT2 film compared to EBT at wavelengths especially below approximately 550 n m. At wavelengths above 550 n m differences in absolute OD are seen however, when dose analysis is performed at wavelengths above 550 n m using net optical density changes, no significant variations are seen. If comparing results of the late production EBT to new production EBT2 film, net optical density variations of approximately 10 % to 15 % are seen. As all new film batches should be calibrated for sensitivity upon arrival this should not be of concern.

  17. Update of diagnostic medical and dental x-ray exposures in Romania

    Energy Technology Data Exchange (ETDEWEB)

    Sorop, Ioana; Mossang, Daniela; Dadulescu, Elena [Radiation Hygiene Laboratory of Public Health Authority Dolj, 2, Constantin Lecca Street, Craiova (Romania); Iacob, Mihai Radu [University ' Alexandru Ioan Cuza' , 11, Carol I Street, 700506, Iasi (Romania); Iacob, Olga [Institute of Public Health, 14, Victor Babes Street, 700465 Iasi (Romania)], E-mail: danamossang@sanpubdj.ro

    2008-12-15

    This national study, the third in the last 15 years, updates the magnitude of medical radiation exposure from conventional x-ray examinations, in order to optimise the radiological protection to the population in a cost-effective manner. Effective doses from diagnostic radiology were estimated for adult and paediatric patients undergoing the 20 most important types of x-ray examination. Data were collected from 179 x-ray departments, selected by their annual workload, throughout the country. Estimates were made using two dosimetric quantities: entrance surface dose, derived from the absorbed dose in air measured by simulation of radiographic examinations, and dose-area product, measured during fluoroscopic examinations performed on adult and paediatric patients. Conversion coefficients to effective dose of the UK National Radiological Protection Board (NRPB) have been used in all calculations. The effective dose per patient from all medical x-ray examinations was 0.74 mSv and the resulting annual collective effective dose was 6930 man Sv, with annual effective dose per caput of 0.33 mSv. The current size of population exposure from diagnostic radiology is lower than the previous one by 40%, but could be about 30% higher by taking into account the estimated contribution from computed tomography (CT) procedures.

  18. Characterization of titanium silicide thin films by X-ray diffraction techniques

    International Nuclear Information System (INIS)

    Morimoto, N.J.

    1987-01-01

    This thesis deals with characterization techniques of thin films by means of X-ray diffraction. This includes phase identification and residual stress, microstress and crystallite size calculations. The techniques developed were applied on the study of the titanium silicide formation obtained by means of Rapidy Thermal Processing (RTP) pf Ti films deposited on silicon substratum. The different phases were studied in relation with processing temperature and time in one and two anneling steps. The low resistivity TiSi 2 phase was observed for temperature of 700 0 C and higher. The experimental results indicate that the residual stress of TiSi 2 films doesn't vary significantly with the annealing conditions. On the other hand, the microstress is reduced with annealing time at 800 0 C, while the crystallite size is almost not affected. For the microstress and the crystallite size determination technique, two methods were implemented and compared. The Riella's method appeared to be very efficient, while the Gangulle's method seemed to be inadequate, because the results oscillate too much [pt

  19. Degradation of poly(vinyl chloride) films by X-rays radiation

    International Nuclear Information System (INIS)

    Sbampato, M.E.; Kawano, Y.

    1984-01-01

    The degradation of pure poly(vinyl chloride) (PVC) films has been studied by X-rays radiation in vacuum. The films are transparent and become yellow with the exposure of radiation and this colour is enhanced with the time of irradiation. The infrared, ultraviolet and visible spectra changed in the irradiated material. The IR spectra show changes in itensities and band shifting, particularly in the region of C-Cl stretching vibrations indicating the occurrence of dehydrochlorination and a change in the conformation of the degraded PVC. The ultraviolet and visible spectra of irradiated films show a strong absorption band at 240 nm and many shoulders which are associated to dyenes, carbonyl and polyenes with few double bonds formed. The shoulder numbers increase in the spectra of samples kept for three months. This effect indicates that with irradiation, HCl is evolved resulting in the formation of polyenyl radicals, which propagate after irradiation. At the same time, should occur the reaction of these radicals with the atmospheric oxygen with formation of C=0 bonds. (Author) [pt

  20. X-ray equipment for dental diagnostics with a dose-rate controller influencing the exposure voltage

    International Nuclear Information System (INIS)

    Franke, K.

    1980-01-01

    If a synoptic picture is taken of teeth or jaw the X-ray tube and the film carrier with the film and a radiation detector are moving around the patient's head. The detector signal is connected to the input of the actual value of the dose-rate controller containing a scanning and stop circuit with a storing time roughly corresponding to the exposure of three teeth. After the shot the actual value of the dose rate is adjusted to the desired value, thus a constant quality of the following pictures being achieved. (RW) [de

  1. Measurement of high energy x-ray beam penumbra with Gafchromic trade mark sign EBT radiochromic film

    International Nuclear Information System (INIS)

    Cheung Tsang; Butson, Martin J.; Yu, Peter K. N.

    2006-01-01

    High energy x-ray beam penumbra are measured using Gafchromic trade mark sign EBT film. Gafchromic trade mark sign EBT, due to its limited energy dependence and high spatial resolution provide a high level of accuracy for dose assessment in penumbral regions. The spatial resolution of film detector systems is normally limited by the scanning resolution of the densitometer. Penumbral widths (80%/20%) measured at D max were found to be 2.8, 3.0, 3.2, and 3.4 mm (±0.2 mm) using 5, 10, 20, and 30 cm square field sizes, respectively, for a 6 MV linear accelerator produced x-ray beam. This is compared to 3.2 mm±0.2 mm (Kodak EDR2) and 3.6 mm±0.2 mm (Kodak X-Omat V) at 10 cmx10 cm measured using radiographic film. Using a zero volume extrapolation technique for ionization chamber measurements, the 10 cmx10 cm field penumbra at D max was measured to be 3.1 mm, a close match to Gafchromic trade mark sign EBT results. Penumbral measurements can also be made at other depths, including the surface, as the film does not suffer significantly from dosimetric variations caused by changing x-ray energy spectra. Gafchromic trade mark sign EBT film provides an adequate measure of penumbral dose for high energy x-ray beams

  2. Influence of annealing on X-ray radiation sensing properties of TiO2 thin film

    Science.gov (United States)

    Sarma, M. P.; Kalita, J. M.; Wary, G.

    2018-03-01

    A recent study shows that the titanium dioxide (TiO2) thin film synthesised by a chemical bath deposition technique is a very useful material for the X-ray radiation sensor. In this work, we reported the influence of annealing on the X-ray radiation detection sensitivity of the TiO2 film. The films were annealed at 333 K, 363 K, 393 K, 473 K, and 573 K for 1 hour. Structural analyses showed that the microstrain and dislocation density decreased whereas the average crystallite size increased with annealing. The band gap of the films also decreased from 3.26 eV to 3.10 eV after annealing. The I-V characteristics record under the dark condition and under the X-ray irradiation showed that the conductivity increased with annealing. The influence of annealing on the detection sensitivity was negligible if the bias voltage applied across the films was low (within 0.2 V‒1.0 V). At higher bias voltage (>1.0 V), the contribution of electrons excited by X-ray became less significant which affected the detection sensitivity.

  3. Structural and X-Ray Photoelectron Spectroscopy Study of Al-Doped Zinc-Oxide Thin Films

    Directory of Open Access Journals (Sweden)

    Bong Ju Lee

    2015-01-01

    Full Text Available Al-doped zinc-oxide (AZO thin films were prepared by RF magnetron sputtering at different oxygen partial pressures and substrate temperatures. The charge-carrier concentrations in the films decreased from 1.69 × 1021 to 6.16 × 1017 cm−3 with increased gas flow rate from 7 to 21 sccm. The X-ray diffraction (XRD patterns show that the (002/(103 peak-intensity ratio decreased as the gas flow rate increased, which was related to the increase of AZO thin film disorder. X-ray photoelectron spectra (XPS of the O1s were decomposed into metal oxide component (peak A and the adsorbed molecular oxygen on thin films (peak B. The area ratio of XPS peaks (A/B was clearly related to the stoichiometry of AZO films; that is, the higher value of A/B showed the higher stoichiometric properties.

  4. X-ray Photon Correlation Spectroscopy Study on Dynamics of the Free Surface in Entangled Polystyrene Melt Films

    International Nuclear Information System (INIS)

    Koga, Tadanori; Li Chunhua; Endoh, Maya K; Narayanan, Suresh; Lurio, Laurence; Sinha, Sunil K

    2011-01-01

    The dynamics of polymer chains near the surface of a melt and within thin films remains a subject of inquiry along with the nature of the glass transition in these systems. Recent studies show that the properties of the free surface region are crucial in determining the anomalous glass transition temperature (T g ) reduction of polymer thin films. In this study, by embedding 'dilute' gold nanoparticles in polystyrene (PS) thin films as 'markers', we could successfully probe the diffusive Brownian motion which tracks the local viscosity both at the free surface and within the rest of the single PS thin film far above bulk T g . The technique used was X-ray photon correlation spectroscopy with resonance-enhanced X-rays that allows us to independently measure the motion in the regions of interest at the nanometer scale. We found the presence of the surface reduced viscosity layer in entangled PS thin films at T>>T g .

  5. Recent Developments in the X-Ray Reflectivity Analysis for Rough Surfaces and Interfaces of Multilayered Thin Film Materials

    Directory of Open Access Journals (Sweden)

    Yoshikazu Fujii

    2013-01-01

    Full Text Available X-ray reflectometry is a powerful tool for investigations on rough surface and interface structures of multilayered thin film materials. The X-ray reflectivity has been calculated based on the Parratt formalism, accounting for the effect of roughness by the theory of Nevot-Croce conventionally. However, in previous studies, the calculations of the X-ray reflectivity often show a strange effect where interference effects would increase at a rough surface. And estimated surface and interface roughnesses from the X-ray reflectivity measurements did not correspond to the TEM image observation results. The strange result had its origin in a used equation due to a serious mistake in which the Fresnel transmission coefficient in the reflectivity equation is increased at a rough interface because of a lack of consideration of diffuse scattering. In this review, a new accurate formalism that corrects this mistake is presented. The new accurate formalism derives an accurate analysis of the X-ray reflectivity from a multilayer surface of thin film materials, taking into account the effect of roughness-induced diffuse scattering. The calculated reflectivity by this accurate reflectivity equation should enable the structure of buried interfaces to be analyzed more accurately.

  6. Structural analysis of polymer thin films using GISAXS in the tender X-ray region: Concept and design of GISAXS experiments using the tender X-ray energy at BL-15A2 at the Photon Factory

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, H., E-mail: takagih@post.kek.jp; Igarashi, N.; Mori, T.; Saijo, S.; Nagatani, Y.; Shimizu, N. [Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Ohta, H. [Mitsubishi Electric System & Service Co., Ltd, Accelerator Engineering Center, 2-8- 8 Umezono, Tsukuba, Ibaraki 305-0045 (Japan); Yamamoto, K. [Graduate School of Engineering, Department of Materials Science & Technology, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan)

    2016-10-14

    If small angle X-ray scattering (SAXS) utilizing the soft X-ray region is available, advanced and unique experiments, which differ from traditional SAXS methods, can be realized. For example, grazing-incidence small angle X-ray scattering (GISAXS) using hard X-ray is a powerful tool for understanding the nanostructure in both vertical and lateral directions of thin films, while GISAXS utilizing the tender X-ray region (SX-GISAXS) enables depth-resolved analysis as well as a standard GISAXS analysis in thin films. Thus, at BL-15A2 at the Photon Factory, a dedicated diffractometer for SX-GISAXS (above 2.1 keV) was constructed. This diffractometer is composed of four vacuum chambers and can be converted into the vacuum state from the sample chamber in front of the detector surface. Diffractions are clearly observed until 12th peak when measuring collagen by SAXS with an X-ray energy of 2.40 keV and a camera length of 825 mm. Additionally, we conducted the model experiment using SX-GISAXS with an X-ray energy of 2.40 keV to confirm that a poly(methyl methacrylate)-poly(n-butyl acrylate) block copolymer thin film has a microphase-separated structure in the thin film, which is composed of lamellae aligned both parallel and perpendicular to the substrate surface. Similarly, in a polystyrene-poly(methyl methacrylate) block copolymer thin film, SX-GISAXS with 3.60 keV and 5.73 keV revealed that hexagonally packed cylinders are aligned parallel to the substrate surface. The incident angle dependence of the first order peak position of the q{sub z} direction obtained from experiments at various incident X-ray energies agrees very well with the theoretical one calculated from the distorted wave Born approximation.

  7. Structural analysis of polymer thin films using GISAXS in the tender X-ray region: Concept and design of GISAXS experiments using the tender X-ray energy at BL-15A2 at the Photon Factory

    International Nuclear Information System (INIS)

    Takagi, H.; Igarashi, N.; Mori, T.; Saijo, S.; Nagatani, Y.; Shimizu, N.; Ohta, H.; Yamamoto, K.

    2016-01-01

    If small angle X-ray scattering (SAXS) utilizing the soft X-ray region is available, advanced and unique experiments, which differ from traditional SAXS methods, can be realized. For example, grazing-incidence small angle X-ray scattering (GISAXS) using hard X-ray is a powerful tool for understanding the nanostructure in both vertical and lateral directions of thin films, while GISAXS utilizing the tender X-ray region (SX-GISAXS) enables depth-resolved analysis as well as a standard GISAXS analysis in thin films. Thus, at BL-15A2 at the Photon Factory, a dedicated diffractometer for SX-GISAXS (above 2.1 keV) was constructed. This diffractometer is composed of four vacuum chambers and can be converted into the vacuum state from the sample chamber in front of the detector surface. Diffractions are clearly observed until 12th peak when measuring collagen by SAXS with an X-ray energy of 2.40 keV and a camera length of 825 mm. Additionally, we conducted the model experiment using SX-GISAXS with an X-ray energy of 2.40 keV to confirm that a poly(methyl methacrylate)-poly(n-butyl acrylate) block copolymer thin film has a microphase-separated structure in the thin film, which is composed of lamellae aligned both parallel and perpendicular to the substrate surface. Similarly, in a polystyrene-poly(methyl methacrylate) block copolymer thin film, SX-GISAXS with 3.60 keV and 5.73 keV revealed that hexagonally packed cylinders are aligned parallel to the substrate surface. The incident angle dependence of the first order peak position of the q_z direction obtained from experiments at various incident X-ray energies agrees very well with the theoretical one calculated from the distorted wave Born approximation.

  8. On X-ray diffraction study of microstructure of ZnO thin nanocrystalline films with strong preferred grain orientation

    Czech Academy of Sciences Publication Activity Database

    Kužel, R.; Čížek, J.; Novotný, Michal

    44A, č. 1 (2013), s. 45-57 ISSN 1073-5623 R&D Projects: GA ČR(CZ) GAP108/11/0958 Institutional support: RVO:68378271 Keywords : zinc oxide thin film * X-ray diffraction * Mg0 * fused silica Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.730, year: 2013

  9. Quantitative X-ray spectral microanalysis of bioorganic films by means of a crystal-diffraction spectrometer

    International Nuclear Information System (INIS)

    Pogorelov, A.G.; Pogorelova, V.N.; Khrenova, E.V.; Gol'dshtejn, D.V.; Aksirov, A.M.; Kantor, G.M.

    2005-01-01

    The details of the quantitative X-ray spectral microanalysis performed with a wave dispersive spectrometer are described. Hydration of biological tissues, light element composition, low concentration of analyzed elements and their nonuniform distribution are the specific features of bioorganic film and tissue section. This paper is aimed to discuss the general approaches to both preparation technique and quantitative analysis principles [ru

  10. Correlation of conventional simulation x-ray films and CT images for HDR-brachytherapy catheters reconstruction

    International Nuclear Information System (INIS)

    Rajendran, M.; Reddy, K.D.; Reddy, R.M.; Reddy, J.M.; Reddy, B.V.N.; Kiran Kumar; Gopi, S.; Dharaniraj; Janardhanan

    2002-01-01

    In order to plan a brachytherapy implant, it is imperative that implant reconstruction is done accurately. The purpose of this paper is to evaluate whether implant reconstruction done with transverse CT images is comparable to reconstruction done with conventional x-ray films

  11. Hydrogen concentration and mass density of diamondlike carbon films obtained by x-ray and neutron reflectivity

    DEFF Research Database (Denmark)

    Findeisen, E.; Feidenhans'l, R.; Vigild, Martin Etchells

    1994-01-01

    Specular reflectivity of neutrons and x rays can be used to determine the scattering length density profile of a material perpendicular to its surface. We have applied these techniques to study amorphous, diamondlike, hydrocarbon films. By the combination of these two techniques we obtain not onl...

  12. Orientation of One-Dimensional Silicon Polymer Films Studied by X-Ray Absorption Spectroscopy

    Directory of Open Access Journals (Sweden)

    Md. Abdul Mannan

    2012-01-01

    Full Text Available Molecular orientations for thin films of one-dimensional silicon polymers grown by vacuum evaporation have been assigned by near-edge X-ray absorption fine structure (NEXAFS using linearly polarized synchrotron radiation. The polymer investigated was polydimethylsilane (PDMS which is the simplest stable silicon polymer, and one of the candidate materials for one-dimensional molecular wire. For PDMS films deposited on highly oriented pyrolytic graphite (HOPG, four resonance peaks have been identified in the Si K-edge NEXAFS spectra. Among these peaks, the intensities of the two peaks lower-energy at 1842.0 eV and 1843.2 eV were found to be strongly polarization dependent. The peaks are assigned to the resonance excitations from the Si 1s to σ∗ pyz and σ∗ px orbitals localized at the Si–C and Si–Si bonds, respectively. Quantitative evaluation of the polarization dependence of the NEXAFS spectra revealed that the molecules are self-assembled on HOPG surface, and the backbones of the PDMS are oriented nearly parallel to the surface. The observed orientation is opposite to the previously observed results for PDMS on the other surfaces such as oxide (indium tin oxide and metal (polycrystalline copper. The flat-lying feature of PDMS observed only on HOPG surface is attributed to the interaction between CH bonds in PDMS and π orbitals in HOPG surface.

  13. Parallel beam microradiography of dental hard tissue using synchrotron radiation and X-ray image magnification

    International Nuclear Information System (INIS)

    Takagi, S.; Chow, L.C.; Brown, W.E.; Dobbyn, R.C.; Kuriyama, M.

    1984-01-01

    A novel technique utilizing a highly parallel beam of monochromatic synchrotron radiation combined with X-ray image magnification has been used to obtain microradiographs of caries lesions in relatively thick tooth sections. Preliminary results reveal structural features not previously reported. This technique holds the promise of allowing one to follow the structural changes accompanying the formation, destruction and chemical repair of mineralized tissue in real time. (orig.)

  14. Evaluation of patient dose in imaging using a cone-beam CT dosimetry by X-ray films for radiotherapeutic dose

    International Nuclear Information System (INIS)

    Yoshida, Yuri; Morita, Yasuhiko; Honda, Eiichi; Tomotake, Yoritoki; Ichikawa, Tetsuo

    2008-01-01

    A limited cone-beam X-ray CT (3DX multi-image micro CT; 3DX-FPD) is widely used in dentistry because it provides a lower cost, smaller size, and higher spatial resolution than a CT for medicine. Our recent research suggested that the patient dose of 3DX-FPD was less than 7/10 of that of CT, and it was several to 10 times more than that of dental or panoramic radiography. The purpose of this study was to evaluate the spatial dose distribution from 3DX-FPD and to estimate the influence of dose by positioning of the region of interest. Dosimetry of the organs and the tissues was performed using an anthropomorphic Alderson Rando phantom and X-ray films for measurement of radiotherapeutic dose. Measurements of dose distribution were performed using a cylinder-type tank of water made of acrylic resin imitating the head and X-ray films. The results are summarized as follows: The dose was higher as the ratio of the air region included in the region of interest increased. The dose distribution was not homogeneous and the dose was highest in the skin region. The dose was higher for several seconds after the beginning of exposure. It was concluded that patient positioning, as well as exposure conditions including the size of the exposure field and tube current, could greatly influence the patient dose in 3DX-FPD. In addition, it is necessary to consider the influence of image quality for the treatment of dental implants. (author)

  15. Genetic damage in exfoliated cells from oral mucosa of individuals exposed to X-rays during panoramic dental radiographies.

    Science.gov (United States)

    Cerqueira, E M M; Gomes-Filho, I S; Trindade, S; Lopes, M A; Passos, J S; Machado-Santelli, G M

    2004-08-08

    The genotoxic effects of X-ray emitted during dental panoramic radiography were evaluated in exfoliated cells from oral epithelium through a differentiated protocol of the micronucleus test. Thirty-one healthy individuals agreed to participate in this study and were submitted to this procedure for diagnosis purpose after being requested by the dentist. All of them answered a questionnaire before the examination. Cells were obtained from both sides of the cheek by gentle scrapping with a cervical brush, immediately before the exposure and after 10 days. Cytological preparations were stained according to Feulgen-Rossenbeck reaction and analyzed under light and laser scanning confocal microscopies. Micronuclei, nuclear projections (buds and broken eggs) and degenerative nuclear alterations (condensed chromatin, karyolysis and karyorrhexis) were scored. The frequencies of micronuclei, karyolysis and pycnosis were similar before and after exposure (P > 0.90), whereas the condensation of the chromatin and the karyorrhexis increased significantly after exposure (P structures are associated to the normal epithelium differentiation. The results suggest that the X-ray exposure during panoramic dental radiography induces a cytotoxic effect by increasing apoptosis. We also believe that the score of other nuclear alterations in addition to the micronucleus improves the sensitivity of genotoxic effects detection.

  16. Development of flat panel X-ray detector utilizing a CdZnTe film as conversion layer

    International Nuclear Information System (INIS)

    Tokuda, Satoshi; Kishihara, Hiroyuki; Kaino, Masatomo; Sato, Toshiyuki

    2006-01-01

    A polycrystalline CdZnTe film formed by the CSS (closed-spaced sublimation) method is one of the most promising materials as a conversion layer of next-generation highly efficient flat-panel X-ray detectors. Therefore, we have developed a prototype of a new flat-panel X-ray detector (a sensing region of 3 inches by 3 inches) with the film and evaluated its commercial feasibility. This paper describes evaluation of the physical and imaging properties of the prototype and explains the features of the CdZnTe film and the construction, specifications, and fabrication procedures of the prototype. Also included in this paper are formation of a semiconductor thin film barrier layer by the CBD (chemical bath deposition) method and conjunction of a sensor substrate and a TFT array substrate with the bump electrodes formed by screen printing, both of which we have developed during the course of the development of the prototype. (author)

  17. Chemical state analysis of oxide thin films using a high resolution double crystal X-ray fluorescence spectrometer

    International Nuclear Information System (INIS)

    Masuda, Hirohisa; Morinaga, Kenji; Ohta, Yoshio.

    1995-01-01

    The chemical state analysis of r.f.-sputtered amorphous oxide thin films was determined by a high resolution X-ray fluorescence spectrometer with double crystals. The polymerization degree of silicate anions in the silicate film was as same as a target (α-Quartz). The oxygen coordination number of Al 3+ ions in the aluminate film was different from a target (α-Al 2 O 3 ), and it was a mixture of 4 and 6 in a spinel-like structure. In CaO-SiO 2 and CaO-Al 2 O 3 films, when the film thickness is thin at the beginning of sputtering, the composition of films are in the shortage of CaO. But when the film thickness become thicker, the composition of films become as same as the target. From the results above, the chemical state of films and their variations with film thickness can be clarified by using the apparatus. (author)

  18. Unit cell determination of epitaxial thin films based on reciprocal space vectors by high-resolution X-ray diffractometry

    OpenAIRE

    Yang, Ping; Liu, Huajun; Chen, Zuhuang; Chen, Lang; Wang, John

    2013-01-01

    A new approach, based on reciprocal space vectors (RSVs), is developed to determine Bravais lattice types and accurate lattice parameters of epitaxial thin films by high-resolution X-ray diffractometry (HR-XRD). The lattice parameters of single crystal substrates are employed as references to correct the systematic experimental errors of RSVs of thin films. The general procedure is summarized, involving correction of RSVs, derivation of raw unit cell, subsequent conversion to the Niggli unit ...

  19. Structural studies on Langmuir-Blodgett ultra-thin films on tin (IV) stearate using X-ray diffraction technique

    International Nuclear Information System (INIS)

    Mohamad Deraman; Muhamad Mat Salleh; Mohd Ali Sulaiman; Mohd Ali Sufi

    1991-01-01

    X-ray diffraction measurements were carried out on Langmuir-Blodgett (LB) ultra-thin films of tin (IV) stearate for different numbers of layers. The structural information such as interplanar spacing, unit cells spacing, molecular length and orientation of molecular chains were obtained from the diffraction data. This information is discussed and compared with that previously published for LB ultra-thin films of manganese stearate and cadmium stearate

  20. Thin-film-based scintillators for hard x-ray microimaging detectors: the ScinTAX Project

    Science.gov (United States)

    Rack, A.; Cecilia, A.; Douissard, P.-A.; Dupré, K.; Wesemann, V.; Baumbach, T.; Couchaud, M.; Rochet, X.; Riesemeier, H.; Radtke, M.; Martin, T.

    2014-09-01

    The project ScinTAX developed novel thin scintillating films for the application in high performance X-ray imaging and subsequent introduced new X-ray detectors to the market. To achieve this aim lutetium orthosilicate (LSO) scintillators doped with different activators were grown successfully by liquid phase epitaxy. The high density of LSO (7.4 g/cm3), the effective atomic number (65.2) and the high light yield make this scintillator highly applicable for indirect X-ray detection in which the ionizing radiation is converted into visible light and then registered by a digital detector. A modular indirect detection system has been developed to fully exploit the potential of this thin film scintillator for radiographic and tomographic imaging. The system is compatible for high-resolution imaging with moderate dose as well as adaptable to intense high-dose applications where radiation hard microimaging detectors are required. This proceedings article shall review the achieved performances and technical details on this high-resolution detector system which is now available. A selected example application demonstrates the great potential of the optimized detector system for hard X-ray microimaging, i.e. either to improve image contrast due to the availability of efficient thin crystal films or to reduce the dose to the sample.

  1. X-ray film digitization using a personal computer and hand-held scanner: a simple technique for storing images

    International Nuclear Information System (INIS)

    Munoz-Nunez, C. F.; Lloret-Alcaniz, A.

    1998-01-01

    To develop a simple, low-cost technique for the digitization of X-ray films for personal use. A 66-MHz 486 PC with 8 MB of RAM, a Logitech ScanMan 256 hand-held scanner and a standard negatoscope with the power source converted to direct current. Although the system was originally designed for the digitization of mammographies, it has also been used with computed tomography, magnetic resonance, digital angiography and ultrasonographic images, as well as plain X-rays. After a minimal training period, the system digitized X-ray films easily and rapidly. Although the scanning values vary depending on the type of image to be digitized, an input spatial resolution of 200 dpi and a contrast resolution of 256 levels of gray are generally adequate. Of the storage formats tested, JPEG presented the best quality/image size ratio. A simple, low-cost technique has been developed for the digitization of X-ray films. This technique enables the storage of images in a digital format, thus facilitating their presentation and transmission. (Author) 9 refs

  2. A flexible and accurate quantification algorithm for electron probe X-ray microanalysis based on thin-film element yields

    Science.gov (United States)

    Schalm, O.; Janssens, K.

    2003-04-01

    Quantitative analysis by means of electron probe X-ray microanalysis (EPXMA) of low Z materials such as silicate glasses can be hampered by the fact that ice or other contaminants build up on the Si(Li) detector beryllium window or (in the case of a windowless detector) on the Si(Li) crystal itself. These layers act as an additional absorber in front of the detector crystal, decreasing the detection efficiency at low energies (philosophy often employed in quantitative analysis of X-ray fluorescence (XRF) and proton-induced X-ray emission (PIXE) data. This approach is based on the (experimental) determination of thin-film element yields, rather than starting from infinitely thick and single element calibration standards. These thin-film sensitivity coefficients can also be interpolated to allow quantification of elements for which no suitable standards are available. The change in detector efficiency can be monitored by collecting an X-ray spectrum of one multi-element glass standard. This information is used to adapt the previously determined thin-film sensitivity coefficients to the actual detector efficiency conditions valid on the day that the experiments were carried out. The main advantage of this method is that spectra collected from the standards and from the unknown samples should not be acquired within a short period of time. This new approach is evaluated for glass and metal matrices and is compared with a standard ZAF method.

  3. Analysis of Order Formation in Block Copolymer Thin Films UsingResonant Soft X-Ray Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Virgili, Justin M.; Tao, Yuefei; Kortright, Jeffrey B.; Balsara,Nitash P.; Segalman, Rachel A.

    2006-11-27

    The lateral order of poly(styrene-block-isoprene) copolymer(PS-b-PI) thin films is characterized by the emerging technique ofresonant soft X-ray scattering (RSOXS) at the carbon K edge and comparedto ordering in bulk samples of the same materials measured usingconventional small-angle X-ray scattering. We show resonance using theoryand experiment that the loss of scattering intensity expected with adecrease in sample volume in the case of thin films can be overcome bytuning X-rays to the pi* resonance of PS or PI. Using RSOXS, we study themicrophase ordering of cylinder- and phere-forming PS-b-PI thin films andcompare these results to position space data obtained by atomic forcemicroscopy. Our ability to examine large sample areas (~;9000 mu m2) byRSOXS enables unambiguous identification of the lateral lattice structurein the thin films. In the case of the sphere-forming copolymer thin film,where the spheres are hexagonally arranged, the average sphere-to-spherespacing is between the bulk (body-centered cubic) nearest neighbor andbulk unit cell spacings. In the case of the cylinder-forming copolymerthin film, the cylinder-to-cylinder spacing is within experimental errorof that obtained in the bulk.

  4. Panoramic dental radiography with an intra-oral X-ray tube

    International Nuclear Information System (INIS)

    Hollender, L.

    1980-01-01

    Surveys of the complete dentition and jaws can be obtained in various ways. Panoramic radiography with an intra-oral X-ray tube results in a lower radiation exposure than other methods, and is less time-consuming. However, the symmetrical views generally employed result in relatively poor imaging of the molars. This disadvantage can be overcome by using lateral projections which also cause less discomfort for the patient and, particularly in combination with intensifying screens, a further reduction in radiation exposure. Some possible future trends are suggested. (Auth.)

  5. Study of Fe-Ni-Si-B alloy and films on its base by X-ray photospectroscopy method

    International Nuclear Information System (INIS)

    Kozlenko, V.G.; Parfenenok, M.A.; Pukhov, I.K.; Shaposhnikov, A.N.; Shirkov, A.V.

    1983-01-01

    By the method of X ray photoelectron spectroscopy the chemical composition of Fe-Ni-Si-B alloy and films on its base prepared by ion-plasma sputtering is investigated. The identity of chemical bonds in film samples and initial target is revealed, realized are in them mostly Fe-B, Ni-C, Si-Si interatomic bonds. It is shown that lono. films contact with atmosphere is the cause of difference of film composition in the near-surface region (up to 100 nm) from its main volume composition

  6. Image research on acetabular teardrop shadow by X-ray plain-film and CT

    International Nuclear Information System (INIS)

    Wang Xiaoxuan; Zhai Yuejie; Yu Hongguang; Yang Yijun; Zhang Daiwei; Chen Aili; Song Quanjun

    2001-01-01

    Objective: To evaluate the anatomical structure of bone in the formation of acetabular teardrop shadow. Methods: The acetabular teardrop shadow of the X-ray plain-film in 100 children and 300 adults, and of CT in 43 cases were analysed, measured and compared. Results: In children, teardrop shadow appeared 'U' in 80.00%, 14.00% in teardrop, 6.00% in line. In adult teardrop shadow appeared 'U' in 41.33%, 53.33% in teardrop, 5.34% in line. There were significant differences between children and adult in the frequency of 'U' and teardrop (x 2 = 43.34, P 2 = 45.62, P < 0.01). In children, inpeduncle of teardrop shadow was formed of middle 1/3 substantia-line of acetabular concavity inside of pelvis; outpeduncle was formed of middle 1/3 substantia-line of bottom of acetabular. In adult, inpeduncle was formed of middle 1/3 or back 1/3 substantia line of acetabular concavity inside of pelvis; outpeduncle was formed of middle 1/3 or back 1/3 substantia-line of bottom of acetabular. Conclusion: In children, acetabular teardrop shadow was mainly formed of middle 1/3 bone of acetabular concavity. In adult, middle 1/3 or back 1/3 bone of acetabular concavity contribute to the shadow. The ahead 1/3 bone of acetabular concavity is not involved

  7. INVESTIGATIONS THE EFFECT OF EOSIN B DYE ON X- RAY DIFFRACTION PATTERN OF SILVER NITRATE DOPED PVP FILMS

    Directory of Open Access Journals (Sweden)

    Mahasin F. Hadi Al-Kadhemy

    2017-07-01

    Full Text Available In this research, X-ray diffraction of the powder (PVP polymer, Eosin B dye, and silver nitrate and (EB/PVP, AgNO3/PVP, EB/AgNO3/PVP films have been studied. Casting method is used to prepare homogeneous films on plastic petri dishes. All parameters accounted for the X-ray diffraction; full width half maximum (FWHM, Miller indices (hkl, size of crystalline (D, Specific Surface Area (S and Dislocation Density (δ.The nature of the structural of materials and films will be investigated. The XRD pattern of PVP polymer was amorphous structure with two broader peaks and the Eosin B dye and silver nitrate have crystalline structure. While the mixture between these materials led to appearing some crystalline peaks into XRD pattern of PVP polymer.

  8. Quantitative analysis of phosphosilicate glass films on silicon wafers for calibration of x-ray fluorescence spectrometry standards

    International Nuclear Information System (INIS)

    Weissman, S.H.

    1983-01-01

    The phosphorus and silicon contents of phosphosilicate glass films deposited by chemical vapor deposition (CVD) on silicon wafers were determined. These films were prepared for use as x-ray fluorescence (XRF) spectrometry standards. The thin films were removed from the wafer by etching with dilute hydrofluoric acid, and the P and Si concentrations in solution were determined by inductively coupled plasma atomic emission spectroscopy (ICP). The calculated phosphorus concentration ranged from 2.2 to 12 wt %, with an uncertainty of 2.73 to 10.1 relative percent. Variation between the calculated weight loss (summation of P 2 O 5 and SiO 2 amounts as determined by ICP) and the measured weight loss (determined gravimetrically) averaged 4.9%. Results from the ICP method, Fourier transform-infrared spectroscopy (FT-IR), dispersive infrared spectroscopy, electron microprobe, and x-ray fluorescence spectroscopy for the same samples are compared

  9. X-ray Reciprocal Space Mapping of Graded Al x Ga1 - x N Films and Nanowires.

    Science.gov (United States)

    Stanchu, Hryhorii V; Kuchuk, Andrian V; Kladko, Vasyl P; Ware, Morgan E; Mazur, Yuriy I; Zytkiewicz, Zbigniew R; Belyaev, Alexander E; Salamo, Gregory J

    2016-12-01

    The depth distribution of strain and composition in graded Al x Ga1 - x N films and nanowires (NWs) are studied theoretically using the kinematical theory of X-ray diffraction. By calculating [Formula: see text] reciprocal space maps (RSMs), we demonstrate significant differences in the intensity distributions from graded Al x Ga1 - x N films and NWs. We attribute these differences to relaxation of the substrate-induced strain on the NWs free side walls. Finally, we demonstrate that the developed X-ray reciprocal space map model allows for reliable depth profiles of strain and Al composition determination in both Al x Ga1 - x N films and NWs.

  10. X-ray line profile analysis of BaTiO3 thin film prepared by sol-gel deposition

    Science.gov (United States)

    Ooi, Zeen Vee; Saif, Ala'eddin A.; Wahab, Yufridin; Jamal, Zul Azhar Zahid

    2017-04-01

    Barium titanate (BaTiO3) thin film was prepared using sol-gel method and spun-coated on SiO2/Si substrate. The phase and crystallinity of the synthesized film were identified using X-ray diffractometer (XRD), which scanned at the range of 20° to 60°. The phase and lattice parameters of the fabricated film were extracted from the recorded XRD patterns using lattice geometry equations. The crystallite size and lattice strain were determined using X-ray line profile analysis (XLPA) with various approaches. The Scherrer equation was applied to the perovskite peaks of the film to explore the size contribution on the peak broadening. Meanwhile, the Williamson-Hall and size-strain plot (SSP) methods were used to review two main independent contributions, i.e. crystallite sizes and lattice strain, on the X-ray line broadening. From the analysis, it is found that Scherrer method gives smallest crystallite size value by ignoring the strain-induced broadening effect. On the other hand, Williamson-Hall and SSP graphs revealed the existence of the lattice strain within the film, which contributes to the broadening in the Bragg peak. The results that analyzed via both techniques show a linear trend with all data points fitted. However, result obtained from SSP method gives better settlement due to the best fit of the data.

  11. Maintaining radiation exposures as low as reasonably achievable (ALARA) for dental personnel operating portable hand-held x-ray equipment.

    Science.gov (United States)

    McGiff, Thomas J; Danforth, Robert A; Herschaft, Edward E

    2012-08-01

    Clinical experience indicates that newly available portable hand-held x-ray units provide advantages compared to traditional fixed properly installed and operated x-ray units in dental radiography. However, concern that hand-held x-ray units produce higher operator doses than fixed x-ray units has caused regulatory agencies to mandate requirements for use of hand-held units that go beyond those recommended by the manufacturer and can discourage the use of this technology. To assess the need for additional requirements, a hand-held x-ray unit and a pair of manikins were used to measure the dose to a simulated operator under two conditions: exposures made according to the manufacturer's recommendations and exposures made according to manufacturer's recommendation except for the removal of the x-ray unit's protective backscatter shield. Dose to the simulated operator was determined using an array of personal dosimeters and a pair of pressurized ion chambers. The results indicate that the dose to an operator of this equipment will be less than 0.6 mSv y⁻¹ if the device is used according to the manufacturer's recommendations. This suggests that doses to properly trained operators of well-designed, hand-held dental x-ray units will be below 1.0 mSv y⁻¹ (2% of the annual occupational dose limit) even if additional no additional operational requirements are established by regulatory agencies. This level of annual dose is similar to those reported as typical dental personnel using fixed x-ray units and appears to satisfy the ALARA principal for this class of occupational exposures.

  12. X-ray photoelectron spectroscopy (XPS) investigation of the surface film on magnesium powders.

    Science.gov (United States)

    Burke, Paul J; Bayindir, Zeynel; Kipouros, Georges J

    2012-05-01

    Magnesium (Mg) and its alloys are attractive for use in automotive and aerospace applications because of their low density and good mechanical properties. However, difficulty in forming magnesium and the limited number of available commercial alloys limit their use. Powder metallurgy may be a suitable solution for forming near-net-shape parts. However, sintering pure magnesium presents difficulties due to surface film that forms on the magnesium powder particles. The present work investigates the composition of the surface film that forms on the surface of pure magnesium powders exposed to atmospheric conditions and on pure magnesium powders after compaction under uniaxial pressing at a pressure of 500 MPa and sintering under argon at 600 °C for 40 minutes. Initially, focused ion beam microscopy was utilized to determine the thickness of the surface layer of the magnesium powder and found it to be ~10 nm. The X-ray photoelectron analysis of the green magnesium sample prior to sintering confirmed the presence of MgO, MgCO(3)·3H(2)O, and Mg(OH)(2) in the surface layer of the powder with a core of pure magnesium. The outer portion of the surface layer was found to contain MgCO(3)·3H(2)O and Mg(OH)(2), while the inner portion of the layer is primarily MgO. After sintering, the MgCO(3)·3H(2)O was found to be almost completely absent, and the amount of Mg(OH)(2) was also decreased significantly. This is postulated to occur by decomposition of the compounds to MgO and gases during the high temperature of sintering. An increase in the MgO content after sintering supports this theory.

  13. Implementation of a radiation protection framework for medical and dental X-ray diagnostic services in Minas Gerais/Brazil

    International Nuclear Information System (INIS)

    Silva, Teogenes A. da; Pereira, Elton G.; Nogueira, Maria do S.; Ferreira, Hudson R.; Alonso, Thessa C.; Castro, Jose G.L. de; Andrade, Mauricio C.; Joana, Georgia S.; Oliveira, Mauricio de; Cezar, Adriana C. Z.

    2008-01-01

    The Brazilian Sanitary Vigilance Agency is the regulatory authority for radiation protection and quality control of all practices with X-rays for diagnostic purpose. In 1998, the technical regulation 'Guidelines for Radiation Protection in Medical and Dental Radiodiagnostic' was issued by the government that reflected the most updated policy recommended by the International Basic Safety Standards for Protection against Ionizing Radiation. To accomplish the objective of improving radiation protection conditions in the state of Minas Gerais, the Development Centre of Nuclear Technology (CDTN) and the Superintendence of Sanitary Vigilance (SVS) signed a formal cooperation agreement that included: an accreditation process for radiation protection professionals, a follow-up program of the services provided by those professionals, technical support from CDTN for audits carried out by SVS and training of SVS inspectors. Actions to improve and assure metrological reliability of the radiation measurements and special attention to mammography services were done. This paper provides details and results of the radiation protection framework for X-ray radiodiagnostic services in Minas Gerais; the success of the adopted model suggests that it can be used as a basic model to other regions. (author)

  14. X-ray photoelectron spectroscopy study of the growth kinetics of biomimetically grown hydroxyapatite thin-film coatings

    International Nuclear Information System (INIS)

    McLeod, K.; Kumar, S.; Dutta, N.K.; Smart, R.St.C.; Voelcker, N.H.; Anderson, G.I.

    2010-01-01

    Hydroxyapatite (HA) thin-film coatings grown biomimetically using simulated body fluid (SBF) are desirable for a range of applications such as improved fixation of fine- and complex-shaped orthopedic and dental implants, tissue engineering scaffolds and localized and sustained drug delivery. There is a dearth of knowledge on two key aspects of SBF-grown HA coatings: (i) the growth kinetics over short deposition periods, hours rather than weeks; and (ii) possible difference between the coatings deposited with and without periodic SBF replenishment. A study centred on these aspects is reported. X-ray photoelectron spectroscopy (XPS) has been used to study the growth kinetics of SBF-grown HA coatings for deposition periods ranging from 0.5 h to 21 days. The coatings were deposited with and without periodic replenishment of SBF. The XPS studies revealed that: (i) a continuous, stable HA coating fully covered the titanium substrate after a growth period of 13 h without SBF replenishment; (ii) thicker HA coatings about 1 μm in thickness resulted after a growth period of 21 days, both with and without SBF replenishment; and (iii) the Ca/P ratio at the surface of the HA coating was significantly lower than that in its bulk. No significant difference between HA grown with and without periodic replenishment of SBF was found. The coatings were determined to be carbonated, a characteristic desirable for improved implant fixation. The atomic force and scanning electron microscopies results suggested that heterogeneous nucleation and growth are the primary deposition mode for these coatings. Primary osteoblast cell studies demonstrated the biocompatibility of these coatings, i.e., osteoblast colony coverage of approximately 80%, similar to the control substrate (tissue culture polystyrene).

  15. X-ray photoelectron spectroscopy study of the growth kinetics of biomimetically grown hydroxyapatite thin-film coatings

    Energy Technology Data Exchange (ETDEWEB)

    McLeod, K. [Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095 (Australia); Kumar, S., E-mail: sunil.kumar@unisa.edu.au [Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095 (Australia); Dutta, N.K. [Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095 (Australia); Smart, R.St.C. [Applied Centre for Structural and Synchrotron Studies, University of South Australia, Mawson Lakes, SA 5095 (Australia); Voelcker, N.H. [School of Chemistry, Physics and Earth Sciences, Flinders University of South Australia, GPO Box 2100, Adelaide 5001 (Australia); Anderson, G.I. [School of Veterinary Science, University of Adelaide, Adelaide, SA 5005 (Australia)

    2010-09-15

    Hydroxyapatite (HA) thin-film coatings grown biomimetically using simulated body fluid (SBF) are desirable for a range of applications such as improved fixation of fine- and complex-shaped orthopedic and dental implants, tissue engineering scaffolds and localized and sustained drug delivery. There is a dearth of knowledge on two key aspects of SBF-grown HA coatings: (i) the growth kinetics over short deposition periods, hours rather than weeks; and (ii) possible difference between the coatings deposited with and without periodic SBF replenishment. A study centred on these aspects is reported. X-ray photoelectron spectroscopy (XPS) has been used to study the growth kinetics of SBF-grown HA coatings for deposition periods ranging from 0.5 h to 21 days. The coatings were deposited with and without periodic replenishment of SBF. The XPS studies revealed that: (i) a continuous, stable HA coating fully covered the titanium substrate after a growth period of 13 h without SBF replenishment; (ii) thicker HA coatings about 1 {mu}m in thickness resulted after a growth period of 21 days, both with and without SBF replenishment; and (iii) the Ca/P ratio at the surface of the HA coating was significantly lower than that in its bulk. No significant difference between HA grown with and without periodic replenishment of SBF was found. The coatings were determined to be carbonated, a characteristic desirable for improved implant fixation. The atomic force and scanning electron microscopies results suggested that heterogeneous nucleation and growth are the primary deposition mode for these coatings. Primary osteoblast cell studies demonstrated the biocompatibility of these coatings, i.e., osteoblast colony coverage of approximately 80%, similar to the control substrate (tissue culture polystyrene).

  16. Experimental study and analytical model of deformation of magnetostrictive films as applied to mirrors for x-ray space telescopes.

    Science.gov (United States)

    Wang, Xiaoli; Knapp, Peter; Vaynman, S; Graham, M E; Cao, Jian; Ulmer, M P

    2014-09-20

    The desire for continuously gaining new knowledge in astronomy has pushed the frontier of engineering methods to deliver lighter, thinner, higher quality mirrors at an affordable cost for use in an x-ray observatory. To address these needs, we have been investigating the application of magnetic smart materials (MSMs) deposited as a thin film on mirror substrates. MSMs have some interesting properties that make the application of MSMs to mirror substrates a promising solution for making the next generation of x-ray telescopes. Due to the ability to hold a shape with an impressed permanent magnetic field, MSMs have the potential to be the method used to make light weight, affordable x-ray telescope mirrors. This paper presents the experimental setup for measuring the deformation of the magnetostrictive bimorph specimens under an applied magnetic field, and the analytical and numerical analysis of the deformation. As a first step in the development of tools to predict deflections, we deposited Terfenol-D on the glass substrates. We then made measurements that were compared with the results from the analytical and numerical analysis. The surface profiles of thin-film specimens were measured under an external magnetic field with white light interferometry (WLI). The analytical model provides good predictions of film deformation behavior under various magnetic field strengths. This work establishes a solid foundation for further research to analyze the full three-dimensional deformation behavior of magnetostrictive thin films.

  17. Behavior analysis in consumer affairs: encouraging dental professionals to provide consumers with shielding from unnecessary X-ray exposure

    International Nuclear Information System (INIS)

    Greene, B.F.; Neistat, M.D.

    1983-01-01

    An unobtrusive observation system was developed to determine the extent to which dental professionals in two communities provided lead shielding to patients during X-ray exams. A lengthy baseline revealed low and irregular provision of shielding among half of these professionals. Subsequently, a program was undertaken by a consumer's group in which these professionals were requested to provide shielding and were given confidential feedback regarding its use during the baseline period. The provision of shielding dramatically increased at all offices and was maintained throughout a follow-up period extending to more than 9 months after the program's implementation. Little or no generalized effect was observed in the occurrence of three collateral behaviors that were also assessed throughout the study

  18. Micro energy-dispersive X-ray fluoresence mapping of enamel and dental materials after chemical erosion.

    Science.gov (United States)

    Soares, Luís Eduardo Silva; de Oliveira, Rodrigo; Nahórny, Sídnei; Santo, Ana Maria do Espírito; Martin, Airton Abrahão

    2012-10-01

    Energy-dispersive X-ray fluorescence was employed to test the hypothesis that beverage consumption or mouthwash utilization will change the chemical properties of dental materials and enamel mineral content. Bovine enamel samples (n = 45) each received two cavity preparations (n = 90), each pair filled with one of three dental materials (R: nanofilled composite resin; GIC: glass-ionomer cement; RMGIC: resin-modified GIC). Furthermore, they were treated with three different solutions (S: saliva; E: erosion/Pepsi Twist®; or EM: erosion+mouthwash/Colgate Plax®). It was found that mineral loss in enamel was greater in GICE samples than in RE > RMGICE > RMGICEM > REM > GICEM. An increased percentage of Zr was found in REM indicating organic matrix degradation. Dental materials tested (R, GIC, and RMGIC) were not able to protect adjacent enamel from acid erosion by the soft drink tested. The use of mouthwash promoted protection of enamel after erosion by the soft drink. To avoid chemical dissolution by mouthwashes, protection by resin composites with surface sealants is recommended.

  19. Characterization of thin-film multilayers using magnetization curves and modeling of low-angle X-ray diffraction data

    Energy Technology Data Exchange (ETDEWEB)

    Lane, M. [Emory & Henry College, VA (United States); Chaiken, A.; Michel, R.P. [Lawrence Livermore National Lab., CA (United States)

    1994-12-01

    We have characterized thin-film multilayers grown by ion-beam sputtering using magnetization curves and modeling of low-angle x-ray diffraction data. In our films, we use ferromagnetic layer = Co, Fe, and NiFe and spacer layer = Si, Ge, FeSi{sub 2}, and CoSi{sub 2}. We have studied the effects of (1) deposition conditions; (2) thickness of layers; (3) different layer materials; and (4) annealing. We find higher magnetization in films grown at 1000V rather than 500V and in films with spacer layers of 50{angstrom} rather than 100{angstrom}. We find higher coercivity in films with cobalt grown on germanium rather than silicon, metal grown on gold underlayers rather than on glass substrates, and when using thinner spacer layers. Finally, modeling reveals that films grown with disilicide layers are more thermally stable than films grown with silicon spacer layers.

  20. Oxidation of nanostructured Ti films produced by low energy cluster beam deposition: An X-ray Photoelectron Spectroscopy characterization

    International Nuclear Information System (INIS)

    Simone, Monica de; Snidero, Elena; Coreno, Marcello; Bongiorno, Gero; Giorgetti, Luca; Amati, Matteo; Cepek, Cinzia

    2012-01-01

    We used in-situ X-ray Photoelectron Spectroscopy (XPS) to study the oxidation process of a cluster-assembled metallic titanium film exposed to molecular oxygen at room temperature. The nanostructured film has been grown on a Si(111) substrate, in ultra high vacuum conditions, by coupling a supersonic cluster beam deposition system with an XPS experimental chamber. Our results show that upon in-situ oxygen exposure Ti 3+ is the first oxidation state observed, followed by Ti 4+ , whereas Ti 2+ is practically absent during the whole process. Our results compare well with the existing literature on Ti films produced using other techniques.

  1. X-ray spectral determination of chemical state of phosphorus and sulfur in anodic oxide films on niobium

    International Nuclear Information System (INIS)

    Bokij, L.P.; Kostikov, Yu.P.

    1989-01-01

    Chemical forms of phosphorus and sulfur in niobium oxide anodic film, obtained by electrochemical technique using niobium in H 2 SO 4 and H 3 PO 4 aqueous solutions, are determined using data on chemical shifts of X-ray emission lines. Films represent Nb 2 O 5(1-γ) (SO 4 ) 5γ and Nb 2 O 5(1-γ) (PO 4 ) 10γ/3 (γ -share of oxygen substituted by acid anion) composition oxosalts. Electrolyte role in formation of niobium anodic oxide structure and effect of phosphorus and sulfur compounds on anodic film conductivity are determined

  2. Relaxation mechanisms in a gold thin film on a compliant substrate as revealed by X-ray diffraction

    Science.gov (United States)

    Godard, Pierre; Renault, Pierre-Olivier; Faurie, Damien; Thiaudière, Dominique

    2017-05-01

    The fact that the polymeric substrate does not relax after a load jump allows realizing an original relaxation experiment of a metallic thin film. Thanks to the combination of two strain probes done at different scales, namely, X-ray synchrotron diffraction and digital image correlation techniques, the apparent activation volumes are monitored and their values help to capture leading deformation mechanisms in thin films. Such experiments have been performed on a nanocrystalline gold thin film, and deformation mechanisms involved during a biaxial straining have been distinguished between different texture components.

  3. A method for thickness determination of thin films of amalgamable metals by total-reflection X-ray fluorescence

    International Nuclear Information System (INIS)

    Bennun, L.; Greaves, E.D.; Barros, H.; Diaz-Valdes, J.

    2009-01-01

    A method for thickness determination of thin amalgamable metallic films by total-reflection X-ray fluorescence (TXRF) is presented. The peak's intensity in TXRF spectra are directly related to the surface density of the sample, i.e. to its thickness in a homogeneous film. Performing a traditional TXRF analysis on a thin film of an amalgamated metal, and determining the relative peak intensity of a specific metal line, the layer thickness can be precisely obtained. In the case of gold thickness determination, mercury and gold peaks overlap, hence we have developed a general data processing scheme to achieve the most precise results.

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... The x-ray tube is connected to a flexible arm that is extended over the patient while an x-ray film holder or image recording plate is placed beneath the patient. top of page How does the procedure work? X-rays are a form of radiation like ...

  5. High spatial resolution grain orientation and strain mapping in thin films using polychromatic submicron x-ray diffraction

    Science.gov (United States)

    Tamura, N.; MacDowell, A. A.; Celestre, R. S.; Padmore, H. A.; Valek, B.; Bravman, J. C.; Spolenak, R.; Brown, W. L.; Marieb, T.; Fujimoto, H.; Batterman, B. W.; Patel, J. R.

    2002-05-01

    The availability of high brilliance synchrotron sources, coupled with recent progress in achromatic focusing optics and large area two-dimensional detector technology, has allowed us to develop an x-ray synchrotron technique that is capable of mapping orientation and strain/stress in polycrystalline thin films with submicron spatial resolution. To demonstrate the capabilities of this instrument, we have employed it to study the microstructure of aluminum thin film structures at the granular and subgranular levels. Due to the relatively low absorption of x-rays in materials, this technique can be used to study passivated samples, an important advantage over most electron probes given the very different mechanical behavior of buried and unpassivated materials.

  6. Comparison of simulated light sensitometer and x-ray sensitometer for screen-film system in medical radiology

    International Nuclear Information System (INIS)

    Tsuyama, Yasuko; Yamamoto, Yoshinori.

    1983-01-01

    Sensitometric techniques are used for determining the characteristic curve in medical imaging. In this study intensity-scale (inverse square law, simulated light) methods are used in the determination of radiographic screen-film system characteristic curve. Films which were exposed to simulated light and x-ray were processed in the same automatic processor simultaneously. These curves were overlapped at Net density of 1.0 to compare the curve shapes. The results show there is a good correlation between the density of x-ray sensitometry and that of simulated light sensitometry. The differences of density are within +- 0.12 (+- 10 % log exposure). This applies to both blue sensitive and green sensitive systems. (author)

  7. Texture, residual stress and structural analysis of thin films using a combined X-ray analysis

    International Nuclear Information System (INIS)

    Lutterotti, L.; Chateigner, D.; Ferrari, S.; Ricote, J.

    2004-01-01

    Advanced thin films for today's industrial and research needs require highly specialized methodologies for a successful quantitative characterization. In particular, in the case of multilayer and/or unknown phases a global approach is necessary to obtain some or all the required information. A full approach has been developed integrating novel texture and residual stress methodologies with the Rietveld method (Acta Cryst. 22 (1967) 151) (for crystal structure analysis) and it has been coupled with the reflectivity analysis. The complete analysis can be done at once and offers several benefits: the thicknesses obtained from reflectivity can be used to correct the diffraction spectra, the phase analysis help to identify the layers and to determine the electron density profile for reflectivity; quantitative texture is needed for quantitative phase and residual stress analyses; crystal structure determination benefits of the previous. To achieve this result, it was necessary to develop some new methods, especially for texture and residual stresses. So it was possible to integrate them in the Rietveld, full profile fitting of the patterns. The measurement of these spectra required a special reflectometer/diffractometer that combines a thin parallel beam (for reflectivity) and a texture/stress goniometer with a curved large position sensitive detector. This new diffraction/reflectivity X-ray machine has been used to test the combined approach. Several spectra and the reflectivity patterns have been collected at different tilting angles and processed at once by the special software incorporating the aforementioned methodologies. Some analysis examples will be given to show the possibilities offered by the method

  8. Study on the influence of X-ray tube spectral distribution on the analysis of bulk samples and thin films: Fundamental parameters method and theoretical coefficient algorithms

    International Nuclear Information System (INIS)

    Sitko, Rafal

    2008-01-01

    Knowledge of X-ray tube spectral distribution is necessary in theoretical methods of matrix correction, i.e. in both fundamental parameter (FP) methods and theoretical influence coefficient algorithms. Thus, the influence of X-ray tube distribution on the accuracy of the analysis of thin films and bulk samples is presented. The calculations are performed using experimental X-ray tube spectra taken from the literature and theoretical X-ray tube spectra evaluated by three different algorithms proposed by Pella et al. (X-Ray Spectrom. 14 (1985) 125-135), Ebel (X-Ray Spectrom. 28 (1999) 255-266), and Finkelshtein and Pavlova (X-Ray Spectrom. 28 (1999) 27-32). In this study, Fe-Cr-Ni system is selected as an example and the calculations are performed for X-ray tubes commonly applied in X-ray fluorescence analysis (XRF), i.e., Cr, Mo, Rh and W. The influence of X-ray tube spectra on FP analysis is evaluated when quantification is performed using various types of calibration samples. FP analysis of bulk samples is performed using pure-element bulk standards and multielement bulk standards similar to the analyzed material, whereas for FP analysis of thin films, the bulk and thin pure-element standards are used. For the evaluation of the influence of X-ray tube spectra on XRF analysis performed by theoretical influence coefficient methods, two algorithms for bulk samples are selected, i.e. Claisse-Quintin (Can. Spectrosc. 12 (1967) 129-134) and COLA algorithms (G.R. Lachance, Paper Presented at the International Conference on Industrial Inorganic Elemental Analysis, Metz, France, June 3, 1981) and two algorithms (constant and linear coefficients) for thin films recently proposed by Sitko (X-Ray Spectrom. 37 (2008) 265-272)

  9. Methodology for studying strain inhomogeneities in polycrystalline thin films during in situ thermal loading using coherent x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Vaxelaire, N; Labat, S; Thomas, O [Aix-Marseille University, IM2NP, FST avenue Escadrille Normandie Niemen, F-13397 Marseille Cedex (France); Proudhon, H; Forest, S [MINES ParisTech, Centre des materiaux, CNRS UMR 7633, BP 87, 91003 Evry Cedex (France); Kirchlechner, C; Keckes, J [Erich Schmid Institute for Material Science, Austrian Academy of Science and Institute of Metal Physics, University of Leoben, Jahnstrasse 12, 8700 Leoben (Austria); Jacques, V; Ravy, S [Synchrotron SOLEIL, L' Orme des merisiers, Saint-Aubin BP 48, 91192 Gif-sur-Yvette Cedex (France)], E-mail: nicolas.vaxelaire@univ-cezanne.fr

    2010-03-15

    Coherent x-ray diffraction is used to investigate the mechanical properties of a single grain within a polycrystalline thin film in situ during a thermal cycle. Both the experimental approach and finite element simulation are described. Coherent diffraction from a single grain has been monitored in situ at different temperatures. This experiment offers unique perspectives for the study of the mechanical properties of nano-objects.

  10. Methodology for studying strain inhomogeneities in polycrystalline thin films during in situ thermal loading using coherent x-ray diffraction

    International Nuclear Information System (INIS)

    Vaxelaire, N; Labat, S; Thomas, O; Proudhon, H; Forest, S; Kirchlechner, C; Keckes, J; Jacques, V; Ravy, S

    2010-01-01

    Coherent x-ray diffraction is used to investigate the mechanical properties of a single grain within a polycrystalline thin film in situ during a thermal cycle. Both the experimental approach and finite element simulation are described. Coherent diffraction from a single grain has been monitored in situ at different temperatures. This experiment offers unique perspectives for the study of the mechanical properties of nano-objects.

  11. Determination of the Modulation Transfer Function of Screen-Film Combinations in X-ray photography by the grating method

    International Nuclear Information System (INIS)

    Hoeschen, D.

    1987-01-01

    An intercomparison experiment concerning the determination of the Modulation Transfer Function (MTF) of Screen-Film Combinations in x-ray photography by the grating method was made. Six laboratories located in four countries participated. Each laboratory has used its own, individually developed measurement procedure. The results have shown a surprisingly good agreement, the standard deviation (1 σ value) of MTF values reported by the different laboratories was about ± 0.02

  12. An imitative calculation of W/C, Mo/Si articifial multilayered films' structures and properties as X-ray monochromators

    International Nuclear Information System (INIS)

    Liu Wen; Liu Wenhan; Wu Ziqin

    1989-01-01

    An imitative calculation on W/C and Mo/Si artificial multilayered films have been made. The influences of total period numbers and deviation of period thickness on X-ray diffraction peak were given. Two difference diviations, random fluctuation and system linear deviation have been imitated, their influences on X-ray energy distinguish power have been compared

  13. Technique charts for EC film: direct optical measurements to account for the effects of X-ray scatter

    International Nuclear Information System (INIS)

    Munro, Peter; Jordan, Kevin; Lewis, Craig; Heerema, Tim

    2001-01-01

    Purpose: To develop a method of measuring technique charts for enhanced contrast (EC) film, to demonstrate how X-ray scatter changes the response of EC film, and to generate technique charts for general use. Methods and Materials: We have developed a 'digital cassette' - consisting of a metal plate/phosphor screen, a light guide, a photodiode sensor, and an electrometer - that can be used to measure the light generated in the phosphor screen of the film cassette. In turn, these measurements can be used to generate technique charts for EC film. The digital cassette has been used to measure technique charts for 4-MV and 6-MV X-ray beams for a variety of different phantom thicknesses, field sizes, and phantom-to-cassette air gaps. Results and Discussion: We have observed that the signals generated in an ionization chamber located 9.4 cm behind a 30-cm-thick water-equivalent phantom increase by a factor of 1.9 when the field size is increased from 4x4 cm 2 to 40x40 cm 2 when irradiated by a 6-MV X-ray beam. However, the change in EC film response is a factor of 3.5 under the same conditions. Irradiations to optimally expose the EC film predicted by the digital cassette differ by up to 82% compared to those predicted by ion chamber measurements. Nevertheless, the technique charts measured using the digital cassette predict the response of the EC film to ±0.2 optical density. The overresponse of the EC film is most likely due to low-energy scattered photons, which interact with the high atomic number (Z=64) phosphor screen of the enhanced contrast localization cassette. Therefore, simple solutions, such as placing a high atomic number material above the enhanced contrast localization cassette, can reduce this contribution by scattered photons to the signal generated in the cassettes. Conclusions: We have developed a digital cassette that can make more accurate measurements of the technique charts for EC films. Our measurements show that under some conditions, X-ray

  14. High resolution x-ray scattering studies of strain in epitaxial thin films of yttrium silicide grown on silicon (111)

    International Nuclear Information System (INIS)

    Marthinez-Miranda, L.J.; Santiago-Aviles, J.J.; Siegal, M.P.; Graham, W.R.; Heiney, P.A.

    1990-01-01

    The authors have used high resolution grazing incidence x-ray scattering (GIXS) to study the in- plane and out-of-plane structure of epitaxial YSi 2-x films grown on Si(111), with thicknesses ranging from 85 Angstrom to 510 Angstrom. Their results indicate that the films are strained, and that film strain increases as a function of thickness, with lattice parameters varying from a = 3.846 Angstrom/c = 4.142 Angstrom for the 85 Angstrom film to a = 3.877 Angstrom/c = 4.121 Angstrom for the 510 Angstrom film. The authors correlate these results with an increase in pinhole areal coverage as a function of thickness. In addition, the authors' measurements show no evidence for the existence of ordered silicon vacancies in the films

  15. Analysis of thin films prepared by vacuum-evaporation and dropping solution by Takeoff Angle-Dependent X-Ray Fluorescence spectroscopy at glancing incidence

    International Nuclear Information System (INIS)

    Tsuji, Kouichi; Hirokawa, Kichinosuke; Mitose, Kengo.

    1995-01-01

    We have introduced Takeoff Angle-Dependent X-Ray Fluorescence (TAD-XRF) method for thin film and surface analysis. In this method, the sample on the optically flat substrate is irradiated with the glancing incidence of the primary X-ray, and the fluorescent X-rays emitted from the sample are detected at the glancing takeoff angle. We had previously calculated the relationship between the fluorescent X-ray intensity and the takeoff angle at the glancing incidence. The characterization of the thin film is achieved by investigating the dependence of the fluorescent X-ray intensity on the takeoff angle with the calculated curve. Using this analytical method, we have reported the results of the TAD-XRF measured for the evaporated thin films and the dried films from dropping solution in this paper. The effect of the thickness of the thin film, the density of the substrate and the incident angle on the TAD-XRF curve has been reported. In the case of the dried film from the dropping solution, a broad peak was observed at the takeoff angle which was close to the critical angle for the total reflection of the fluorescent X-ray in the TAD-XRF curve. This broad peak was explained by the double-excitation of the incident beam and the refracted beam of the fluorescent X-ray with the assumption that the X-ray which has a same wavelength to the observed fluorescent X-ray impinges upon the sample surface, because the reciprocity theorem is expected in the X-ray region. (author)

  16. A flexible and accurate quantification algorithm for electron probe X-ray microanalysis based on thin-film element yields

    International Nuclear Information System (INIS)

    Schalm, O.; Janssens, K.

    2003-01-01

    Quantitative analysis by means of electron probe X-ray microanalysis (EPXMA) of low Z materials such as silicate glasses can be hampered by the fact that ice or other contaminants build up on the Si(Li) detector beryllium window or (in the case of a windowless detector) on the Si(Li) crystal itself. These layers act as an additional absorber in front of the detector crystal, decreasing the detection efficiency at low energies (<5 keV). Since the layer thickness gradually changes with time, also the detector efficiency in the low energy region is not constant. Using the normal ZAF approach to quantification of EPXMA data is cumbersome in these conditions, because spectra from reference materials and from unknown samples must be acquired within a fairly short period of time in order to avoid the effect of the change in efficiency. To avoid this problem, an alternative approach to quantification of EPXMA data is proposed, following a philosophy often employed in quantitative analysis of X-ray fluorescence (XRF) and proton-induced X-ray emission (PIXE) data. This approach is based on the (experimental) determination of thin-film element yields, rather than starting from infinitely thick and single element calibration standards. These thin-film sensitivity coefficients can also be interpolated to allow quantification of elements for which no suitable standards are available. The change in detector efficiency can be monitored by collecting an X-ray spectrum of one multi-element glass standard. This information is used to adapt the previously determined thin-film sensitivity coefficients to the actual detector efficiency conditions valid on the day that the experiments were carried out. The main advantage of this method is that spectra collected from the standards and from the unknown samples should not be acquired within a short period of time. This new approach is evaluated for glass and metal matrices and is compared with a standard ZAF method

  17. [The digital reprocessing of under- and overexposed x-ray films with a personal computer].

    Science.gov (United States)

    Fuhrmann, R; Diedrich, P

    1993-02-01

    An image processing work station for digitalizing and interactively manipulating under- and overexposed X-rays was set up by adding modules to an IBM compatible personal computer. Overexposed X-rays can be qualitatively enhanced by means of controlled manipulation of contrast and brightness and by means of the use of various digital filtering techniques. With underexposed X-rays an equalized grey scale can be achieved by means of regulating contrast and brightness. Digital filtering is not required. To assure a high degree of anatomical detail (periodontal ligament) in the digitalized image a maximum pixel of 0.1 mm was defined as a qualitative norm. Since in every digitalization process resolution is diminished, it proved best to select for interactive manipulation out of the total image only the section of interest.

  18. Pair distribution functions of amorphous organic thin films from synchrotron X-ray scattering in transmission mode

    Directory of Open Access Journals (Sweden)

    Chenyang Shi

    2017-09-01

    Full Text Available Using high-brilliance high-energy synchrotron X-ray radiation, for the first time the total scattering of a thin organic glass film deposited on a strongly scattering inorganic substrate has been measured in transmission mode. The organic thin film was composed of the weakly scattering pharmaceutical substance indomethacin in the amorphous state. The film was 130 µm thick atop a borosilicate glass substrate of equal thickness. The atomic pair distribution function derived from the thin-film measurement is in excellent agreement with that from bulk measurements. This ability to measure the total scattering of amorphous organic thin films in transmission will enable accurate in situ structural studies for a wide range of materials.

  19. Synchrotron x-ray-diffraction study of the structure and growth of Xe films adsorbed on the Ag(111) surface

    International Nuclear Information System (INIS)

    Dai, P.; Wu, Z.; Angot, T.; Wang, S.; Taub, H.; Ehrlich, S.N.

    1999-01-01

    Synchrotron x-ray scattering has been used to investigate the structure and growth of perhaps the simplest of all films: xenon physisorbed on the Ag(111) surface. High-resolution x-ray scans of the in-plane structure and lower-resolution scans (specular and nonspecular) of the out-of-plane order were performed. The Xe films were prepared under both quasiequilibrium and kinetic growth conditions, and have fewer structural defects than those investigated previously by others on graphite substrates. Under quasiequilibrium conditions, the bulk Xe-Xe spacing is reached at monolayer completion, and the monolayer and bilayer lattice constants at coexistence are inferred equal to within 0.005 Angstrom, consistent with theoretical calculations. The Xe/vacuum interface profile for a complete monolayer and bilayer grown at quasiequilibrium is found to be sharper than for kinetically grown films. At coverages above two layers, diffraction scans along the Xe(01l) rod for quasiequilibrated films are consistent with the presence of two domains having predominantly an ABC stacking sequence and rotated 60 degree with respect to each other about the surface normal. Annealing of these films alters neither the population of the two domains nor the fraction of ABA stacking faults. The thickest film grown under quasiequilibrium conditions exceeds 220 Angstrom (resolution limited). Under kinetic growth conditions, x-ray intensity oscillations at the Xe anti-Bragg position of the specular rod are observed as a function of time, indicating nearly layer-by-layer growth. Up to four complete oscillations corresponding to a film of eight layers have been observed before the intensity is damped out; the number of oscillations is found to depend on the substrate temperature, the growth rate, and the quality of the Ag(111) substrate. The specular reflectivity from kinetically grown films at nominal coverages of three and four layers has been analyzed using a Gaussian model which gives a film

  20. Thin film beam splitter multiple short pulse generation for enhanced Ni-like Ag x-ray laser emission.

    Science.gov (United States)

    Cojocaru, Gabriel V; Ungureanu, Razvan G; Banici, Romeo A; Ursescu, Daniel; Delmas, Olivier; Pittman, Moana; Guilbaud, Olivier; Kazamias, Sophie; Cassou, Kevin; Demailly, Julien; Neveu, Olivier; Baynard, Elsa; Ros, David

    2014-04-15

    An alternative, novel multiple pulse generation scheme was implemented directly after the optical compressor output of an x-ray pump laser. The new method uses a polarization sensitive thin film beam splitter and a half-wavelength wave plate for tuning the energy ratio in the multiple short pulses. Based on this method, an extensive study was made of the running parameters for a grazing incidence pumped silver x-ray laser (XRL) pumped with a long pulse of 145 mJ in 6 ns at 532 nm and up to 1.45 J in few picoseconds at 810 nm. Fivefold enhancement in the emission of the silver XRL was demonstrated using the new pump method.

  1. X-ray diffraction study of thermal stress relaxation in ZnO films deposited by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Conchon, F. [Institut P' , Universite de Poitiers-Ensma-UPR CNRS 3346, 86962 Futuroscope (France); Renault, P.O., E-mail: pierre.olivier.renault@univ-poitiers.f [Institut P' , Universite de Poitiers-Ensma-UPR CNRS 3346, 86962 Futuroscope (France); Le Bourhis, E.; Krauss, C.; Goudeau, P. [Institut P' , Universite de Poitiers-Ensma-UPR CNRS 3346, 86962 Futuroscope (France); Barthel, E.; Grachev, S. Yu.; Sondergard, E. [Lab. Surface du Verre et Interfaces (SVI), UMR 125, 93303 Aubervilliers (France); Rondeau, V.; Gy, R. [Lab. Recherche de Saint-Gobain (SGR), 93303 Aubervilliers (France); Lazzari, R.; Jupille, J. [Institut des Nanosciences de Paris (INSP), UMR 7588, 75015 Paris (France); Brun, N. [Lab. Physique des Solides (LPS), UMR 8502, 91405 Orsay (France)

    2010-12-30

    X-ray diffraction stress analyses have been performed on two different thin films deposited onto silicon substrate: ZnO and ZnO encapsulated into Si{sub 3}N{sub 4} layers. We showed that both as-deposited ZnO films are in a high compressive stress state. In situ X-ray diffraction measurements inside a furnace revealed a relaxation of the as-grown stresses at temperatures which vary with the atmosphere in the furnace and change with Si{sub 3}N{sub 4} encapsulation. The observations show that Si{sub 3}N{sub 4} films lying on both sides of the ZnO film play an important role in the mechanisms responsible for the stress relaxation during heat treatment. The different temperatures observed for relaxation in ambient and argon atmospheres suggest that the thermally activated stress relaxation may be attributed to a variation of the stoichiometry of the ZnO films. The present observations pave the way to fine tuning of the residual stresses through thermal treatment parameters.

  2. The use of the X-ray investigation for dental caries diagnostics

    International Nuclear Information System (INIS)

    Cecetkova, A.; Ondrasovicova, J.

    2008-01-01

    Caries is defect of the hard dental tissue which is cause by cariogenic microorganisms in the oral cavity. New classification of caries is D1, D2, D3 and D4. D1 is caries in the first layer of enamel. D2 is caries in the second layer of enamel till the margin of dentine ( caries superficial ). D3 is caries in the first layer of dentine ( caries media ).D4 is caries on the top of pulp chamber ( caries pulpae proxima ). One of the most frequently used methods of radiography to detect of caries is bitewing ( BTW ) radiography. (authors)

  3. MONITORING OF INDIVIDUAL DOSES FOR MEDICAL WORKERS OF DENTAL POLYCLINIC’S X-RAY ROOMS IN DUSHANBE, THE REPUBLIC OF TADJIKISTAN

    Directory of Open Access Journals (Sweden)

    N. U. Hakimova

    2016-01-01

    Full Text Available The article presents the data and analyses of personnel’s average annual external exposure doses monitoring via the thermoluminescent dosimetry method used for X-ray radiological personnel in dental polyclinics of Dushanbe, Tadjikistan Republic over a 5-year period ( 2010–2014 . Out of 42 registered medical institutions dental polyclinics amounted up to only just 14%. For this work thermoluminescent dosimeters were used ( with LiF: Mg, Ti with the thermoluminescent dosimetric installation “ Harshaw – 4500” as the reader device. Monitoring results comparison of individual dose equivalent Hp ( 10 values was conducted for two groups of medical workers: medical doctors and X-ray lab technicians. It is demonstrated that radiological technicians’ professional exposure doses are on the average by 23% higher than those for medical doctors.The average individual exposure doses over the above indicated period amount to 0,93 mSv and 1,3 mSv for doctors and X-ray lab technicians, respectively, and are in the range from 0,45 mSv to 2,39 mSv. The doses include contribution from the natural background. The values of doses recorded for the personnel in dental polyclinic correspond to those recorded for the workers in the routine X-ray rooms.

  4. Hard x-ray contact microscopy with 250 nm spatial resolution using a LiF film detector and a tabletop microsource

    International Nuclear Information System (INIS)

    Almaviva, S.; Bonfigli, F.; Franzini, I.; Lai, A.; Montereali, R. M.; Pelliccia, D.; Cedola, A.; Lagomarsino, S.

    2006-01-01

    An innovative route for deep-submicrometer spatial resolution hard x-ray microscopy with tabletop x-ray source is proposed. A film of lithium fluoride (LiF) was used as imaging detector in contact mode. We present here the x-ray images recorded on LiF films of a Fresnel zone plate with submicrometer gold structures and of an onion cataphyll. The images were read with an optical confocal microscope in fluorescence mode. The measured spatial resolution was about 250 nm, i.e., close to the resolution limit of the confocal microscope. The advantages and drawbacks, and the possible improvements, of this route are discussed

  5. Some measurements of doses to patients from dental X-rays

    International Nuclear Information System (INIS)

    Woehni, T.

    1976-01-01

    Some measurements of doses to patients from conventional dental radiography and orthopantomography are presented. Doses to the red bone marrow are calculated. The bone marrow doses from two different exposures, Maxilla incisor and Molar bite-wing, were calculated to be 0.4 and 1.0 mrad respectively. The average dose to red bone marrow from a full-mouth examination (10 exposures) was 0.7 mrad/exposure. An orthopantomographic examination involved 2 mrad to the bone marrow. The greatest doses from an orthopantomographic examination were found around the lateral rotational axis, namely 700 mrad. The dose distributions from the two different cone lengths did not differ as much as expected, mainly due to scattered radiation. (Auth.)

  6. Some measurements of doses to patients from dental X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Woehni, T [Statens Institutt for Straalehygiene, Oslo (Norway)

    1976-11-01

    Some measurements of doses to patients from conventional dental radiography and orthopantomography are presented. Doses to the red bone marrow are calculated. The bone marrow doses from two different exposures, Maxilla incisor and Molar bite-wing, were calculated to be 0.4 and 1.0 mrad respectively. The average dose to red bone marrow from a full-mouth examination (10 exposures) was 0.7 mrad/exposure. An orthopantomographic examination involved 2 mrad to the bone marrow. The greatest doses from an orthopantomographic examination were found around the lateral rotational axis, namely 700 mrad. The dose distributions from the two different cone lengths did not differ as much as expected, mainly due to scattered radiation.

  7. Multiple scattering in grazing-incidence X-ray diffraction: impact on lattice-constant determination in thin films

    Energy Technology Data Exchange (ETDEWEB)

    Resel, Roland, E-mail: roland.resel@tugraz.at; Bainschab, Markus; Pichler, Alexander [Graz University of Technology, Graz (Austria); Dingemans, Theo [Delft University of Technology, Delft (Netherlands); Simbrunner, Clemens [Johannes Kepler University, Linz (Austria); University of Bremen, Bremen (Germany); Stangl, Julian [Johannes Kepler University, Linz (Austria); Salzmann, Ingo [Humboldt University, Berlin (Germany)

    2016-04-20

    The use of grazing-incidence X-ray diffraction to determine the crystal structure from thin films requires accurate positions of Bragg peaks. Refraction effects and multiple scattering events have to be corrected or minimized. Dynamical scattering effects are observed in grazing-incidence X-ray diffraction experiments using an organic thin film of 2,2′:6′,2′′-ternaphthalene grown on oxidized silicon as substrate. Here, a splitting of all Bragg peaks in the out-of-plane direction (z-direction) has been observed, the magnitude of which depends both on the incidence angle of the primary beam and the out-of-plane angle of the scattered beam. The incident angle was varied between 0.09° and 0.25° for synchrotron radiation of 10.5 keV. This study reveals comparable intensities of the split peaks with a maximum for incidence angles close to the critical angle of total external reflection of the substrate. This observation is rationalized by two different scattering pathways resulting in diffraction peaks at different positions at the detector. In order to minimize the splitting, the data suggest either using incident angles well below the critical angle of total reflection or angles well above, which sufficiently attenuates the contributions from the second scattering path. This study highlights that the refraction of X-rays in (organic) thin films has to be corrected accordingly to allow for the determination of peak positions with sufficient accuracy. Based thereon, a reliable determination of the lattice constants becomes feasible, which is required for crystallographic structure solutions from thin films.

  8. Characterization of Scattered X-Ray Photons in Dental Cone-Beam Computed Tomography.

    Science.gov (United States)

    Yang, Ching-Ching

    2016-01-01

    Scatter is a very important artifact causing factor in dental cone-beam CT (CBCT), which has a major influence on the detectability of details within images. This work aimed to improve the image quality of dental CBCT through scatter correction. Scatter was estimated in the projection domain from the low frequency component of the difference between the raw CBCT projection and the projection obtained by extrapolating the model fitted to the raw projections acquired with 2 different sizes of axial field-of-view (FOV). The function for curve fitting was optimized by using Monte Carlo simulation. To validate the proposed method, an anthropomorphic phantom and a water-filled cylindrical phantom with rod inserts simulating different tissue materials were scanned using 120 kVp, 5 mA and 9-second scanning time covering an axial FOV of 4 cm and 13 cm. The detectability of the CT image was evaluated by calculating the contrast-to-noise ratio (CNR). Beam hardening and cupping artifacts were observed in CBCT images without scatter correction, especially in those acquired with 13 cm FOV. These artifacts were reduced in CBCT images corrected by the proposed method, demonstrating its efficacy on scatter correction. After scatter correction, the image quality of CBCT was improved in terms of target detectability which was quantified as the CNR for rod inserts in the cylindrical phantom. Hopefully the calculations performed in this work can provide a route to reach a high level of diagnostic image quality for CBCT imaging used in oral and maxillofacial structures whilst ensuring patient dose as low as reasonably achievable, which may ultimately make CBCT scan a reliable and safe tool in clinical practice.

  9. Characterization of Scattered X-Ray Photons in Dental Cone-Beam Computed Tomography.

    Directory of Open Access Journals (Sweden)

    Ching-Ching Yang

    Full Text Available Scatter is a very important artifact causing factor in dental cone-beam CT (CBCT, which has a major influence on the detectability of details within images. This work aimed to improve the image quality of dental CBCT through scatter correction.Scatter was estimated in the projection domain from the low frequency component of the difference between the raw CBCT projection and the projection obtained by extrapolating the model fitted to the raw projections acquired with 2 different sizes of axial field-of-view (FOV. The function for curve fitting was optimized by using Monte Carlo simulation. To validate the proposed method, an anthropomorphic phantom and a water-filled cylindrical phantom with rod inserts simulating different tissue materials were scanned using 120 kVp, 5 mA and 9-second scanning time covering an axial FOV of 4 cm and 13 cm. The detectability of the CT image was evaluated by calculating the contrast-to-noise ratio (CNR.Beam hardening and cupping artifacts were observed in CBCT images without scatter correction, especially in those acquired with 13 cm FOV. These artifacts were reduced in CBCT images corrected by the proposed method, demonstrating its efficacy on scatter correction. After scatter correction, the image quality of CBCT was improved in terms of target detectability which was quantified as the CNR for rod inserts in the cylindrical phantom.Hopefully the calculations performed in this work can provide a route to reach a high level of diagnostic image quality for CBCT imaging used in oral and maxillofacial structures whilst ensuring patient dose as low as reasonably achievable, which may ultimately make CBCT scan a reliable and safe tool in clinical practice.

  10. Guideline development and impact assessment for registration of medical, dental and veterinary x-ray apparatus

    International Nuclear Information System (INIS)

    Colgan, P.; Harrison, D.; Moore, W.

    1996-01-01

    Under the NSW Radiation Control Act 1990, radiation apparatus used for diagnostic medical, dental and veterinary purposes will be required to become registered. The inspection required prior to registration will be conducted by a Consulting Radiation Expert who has been accredited by the Environment Protection Authority (EPA) as being competent in the field of quality assurance assessment of radiation apparatus used for diagnostic medical, dental and veterinary purposes. When regulating any activity in NSW, there is a requirement to undertake a regulatory impact statement of the proposed regulation. In addition, the introduction of any accompanying guideline requires a cost-benefit analysis. Costs may include enforcement, administrative and compliance activities. The calculation of benefit relies heavily on the improvement in apparatus performance (and hence dose reduction) that can be obtained with the introduction of a mandatory practice such as apparatus registration. This paper discusses the development of the registration guideline for NSW, including a summary of the public comments received. It further discusses the methodology and data used for the accompanying cost-benefit analysis. Information in this paper is presented in three parts: EPA field survey, cost analysis, and benefit analysis. For NSW it was estimated that the introduction of registration of these apparatus, over a two year period, would result in early replacement and repair costs (present values) to the medical industry of between $5.7 and $11.0 million, with an additional $2.5 million in EPA enforcement costs. The introduction of the proposed system of registration is expected to result in an estimated savings in quantifiable health detriment costs to NSW of between $11.8 and $17.7 million, and reduce the risk of radiation induced mortality. (authors)

  11. In situ X-ray diffraction study of crystallization process of GeSbTe thin films during heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Naohiko [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)]. E-mail: e0957@mosk.tytlabs.co.jp; Konomi, Ichiro [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan); Seno, Yoshiki [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan); Motohiro, Tomoyoshi [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)

    2005-05-15

    The crystallization processes of the Ge{sub 2}Sb{sub 2}Te{sub 5} thin film used for PD and DVD-RAM were studied in its realistic optical disk film configurations for the first time by X-ray diffraction using an intense X-ray beam of a synchrotron orbital radiation facility (SPring-8) and in situ quick detection with a Position-Sensitive-Proportional-Counter. The dependence of the amorphous-to-fcc phase-change temperature T{sub 1} on the rate of temperature elevation R{sub et} gave an activation energy E{sub a}: 0.93 eV much less than previously reported 2.2 eV obtained from a model sample 25-45 times thicker than in the real optical disks. The similar measurement on the Ge{sub 4}Sb{sub 1}Te{sub 5} film whose large reflectance change attains the readability by CD-ROM drives gave E{sub a}: 1.13 eV with larger T{sub 1} than Ge{sub 2}Sb{sub 2}Te{sub 5} thin films at any R{sub et} implying a lower sensitivity in erasing as well as a better data stability of the phase-change disk.

  12. X-ray magnetic spectroscopy of MBE-grown Mn-doped Bi2Se3 thin films

    Directory of Open Access Journals (Sweden)

    L. J. Collins-McIntyre

    2014-12-01

    Full Text Available We report the growth of Mn-doped Bi2Se3 thin films by molecular beam epitaxy (MBE, investigated by x-ray diffraction (XRD, atomic force microscopy (AFM, SQUID magnetometry and x-ray magnetic circular dichroism (XMCD. Epitaxial films were deposited on c-plane sapphire substrates by co-evaporation. The films exhibit a spiral growth mechanism typical of this material class, as revealed by AFM. The XRD measurements demonstrate a good crystalline structure which is retained upon doping up to ∼7.5 atomic-% Mn, determined by Rutherford backscattering spectrometry (RBS, and show no evidence of the formation of parasitic phases. However an increasing interstitial incorporation of Mn is observed with increasing doping concentration. A magnetic moment of 5.1 μB/Mn is obtained from bulk-sensitive SQUID measurements, and a much lower moment of 1.6 μB/Mn from surface-sensitive XMCD. At ∼2.5 K, XMCD at the Mn L2,3 edge, reveals short-range magnetic order in the films and indicates ferromagnetic order below 1.5 K.

  13. In situ X-ray diffraction study of crystallization process of GeSbTe thin films during heat treatment

    International Nuclear Information System (INIS)

    Kato, Naohiko; Konomi, Ichiro; Seno, Yoshiki; Motohiro, Tomoyoshi

    2005-01-01

    The crystallization processes of the Ge 2 Sb 2 Te 5 thin film used for PD and DVD-RAM were studied in its realistic optical disk film configurations for the first time by X-ray diffraction using an intense X-ray beam of a synchrotron orbital radiation facility (SPring-8) and in situ quick detection with a Position-Sensitive-Proportional-Counter. The dependence of the amorphous-to-fcc phase-change temperature T 1 on the rate of temperature elevation R et gave an activation energy E a : 0.93 eV much less than previously reported 2.2 eV obtained from a model sample 25-45 times thicker than in the real optical disks. The similar measurement on the Ge 4 Sb 1 Te 5 film whose large reflectance change attains the readability by CD-ROM drives gave E a : 1.13 eV with larger T 1 than Ge 2 Sb 2 Te 5 thin films at any R et implying a lower sensitivity in erasing as well as a better data stability of the phase-change disk

  14. Effect of basic fog of medical x-ray films on image quality and patient dose-method of evaluation and steps to control

    International Nuclear Information System (INIS)

    Bohra, Reena; Nair, C.P.R.; Jayalakshmi, V.; Govindarajan, K.N.; Bhatt, B.C.

    2003-01-01

    Unacceptable basic fog of medical x-ray films has been reported recently from many hospitals. The paper presents the effect of basic fog on radiographic quality of films like sensitivity (speed), contrast and maximum density (DMax). Several batches of general- purpose medical x-ray films from five different manufacturers were studied to evaluate batch-to-batch variation in basic fog. Increase in basic fog with aging of films was also evaluated. Reasons for increased basic fog observed in the film processing facilities of a few hospitals were analysed. Factors responsible for increase in basic fog and the steps to control it have been discussed

  15. X-ray photoelectron spectrometer calibration and thin film investigations on germanium oxides

    OpenAIRE

    Deegan, Terri

    1998-01-01

    The first aim of this project was the characterisation of the VG Scientific Clam 100 based, XPS (X-ray Photoelectron Spectroscopy). Spectrometer in the Physics department at Dublin City University Detailed energy scale and intensity scale calibrations were carried out using sputter-cleaned Au (Gold), Ag (Silver), Cu (Copper) and Pd (Palladium) foil samples. Analysis of these calibration spectra against standard reference spectra led to an accurate energy calibration and the production of indi...

  16. Confocal Raman and PL, AFM, and X-ray diffraction studies of CdS:O thin films

    International Nuclear Information System (INIS)

    Akinori, Suzuki; Kazuki, Wakita; YongGu, Shim; Nazim, Mamedov; Ayaz, Bayramov; Emil, Huseynov

    2010-01-01

    Full text : CdS has much attention as a window material of thin-film solar cells, for example a CdTe solar cell. In this case, increasing band gap of CdS films leads to rise of conversion efficiency of a solar cell. Recently, it was reported that CdS:O films deposited by rf magnetron sputtering consist of nano-crystals of CdS resulting in increasing the band gap. This work reports confocal Raman and photoluminescence (PL), atomic force microscopy (AFM), and X-ray diffraction studies of CdS:O films deposited by cathode sputtering for formation of nano-crystal of CdS. It was shown that AFM image of CdS:O films annealed at 300, 400 and 500 degrees Celsium. The height of peak and dip on the surface is in the range of 5 and 20 nm in the samples annealed at less than 400 degrees Celsium, while the clear crystalline shape appears in the sample annealed at 500 degrees Celsium. There is also shown X-ray diffraction pattern of CdS:O films. As grown film shows amorphous structure of CdS. On the other hand, the samples annealed at 400 and 500 degrees Celsium display obvious crystalline pattern. The crystal radius of the samples annealed at 300, 400, and 500 degrees Celsium were estimated to be 20, 27, and 37 nm, respectively, according to Scherrers formula. Other results related with the confocal spectroscopy will be also presented.

  17. Analysis of Dental Enamel Surface Submitted to Fruit Juice Plus Soymilk by Micro X-Ray Fluorescence: In Vitro Study

    Directory of Open Access Journals (Sweden)

    Janaína Salmos Brito

    2016-01-01

    Full Text Available Objective. This paper aimed to analyze the in vitro industrialized fruit juices effect plus soy to establish the erosive potential of these solutions. Materials and Methods. Seventy bovine incisors were selected after being evaluated under stereomicroscope. Their crowns were prepared and randomly divided into 7 groups, using microhardness with allocation criteria. The crowns were submitted to the fruit juice plus soy during 15 days, twice a day. The pH values, acid titration, and Knoop microhardness were recorded and the specimens were evaluated using X-ray microfluorescence (µXRF. Results. The pH average for all juices and after 3 days was significantly below the critical value for dental erosion. In average, the pH value decreases 14% comparing initial time and pH after 3 days. Comparing before and after, there was a 49% microhardness decrease measured in groups (p<0.05. Groups G1, G2, G5, and G6 are above this average. The analysis by μXRF showed a decrease of approximately 7% Ca and 4% P on bovine crowns surface. Florida (FL statistical analysis showed a statistically significant 1 difference between groups. Thus, a tooth chance to suffer demineralization due to industrialized fruit juices plus soy is real.

  18. The quality of dental radiography in the Czech Republic - Results of a TLD and film postal audit

    International Nuclear Information System (INIS)

    Novak, L.

    2006-01-01

    Since 2002, the postal audit in dental radiography has been supplementing standard quality control (QC) tools for dental intraoral X-ray machines. An aim of the audit is to check basic X-ray machine parameters (field size, exposure reproducibility), and a quality of the whole process of diagnostic imaging (entrance surface air-kerma measurement, a check of film processing and an image quality evaluation). The standard QC tests, performed by private companies, check mainly the X-ray unit. Conversely, the audit gives better information about the patient examination practices. During the period of January 2002 to May 2004 ∼4000 audits were performed. The results confirmed that main problems in dental radiography are due to incorrect film processing, non-optimised setting of the exposure parameters and use of obsolete X-ray machines. Only ∼30% of performed audits were satisfactory with respect to all checked parameters. (authors)

  19. Study of an X-ray fluorescence thin film method for the determination of uranium in low activity solutions

    International Nuclear Information System (INIS)

    Diaz-Guerra, J. P.

    1980-01-01

    The application of the X-ray fluorescence thin film technique to the uranium determination in nitric solutions for a concentration range from 1 g/l to 100 g/l and activity levels under 5 mCi/ml is studied. The most suited excitation and measurement conditions are also studied and the uranium matrix effect correction, which is performed through the double dilution, α U U interaction coefficient calculation and internal standard methods, is discussed. The specimen preparation is satisfactorily accomplished by using P.V.C. filters fixed on aluminium supports. (Author) 18 refs

  20. Thickness determination of thin solid films by angle-resolved X-ray fluorescence spectrometry using monochromatized synchrotron radiation

    Science.gov (United States)

    Schmitt, W.; Drotbohm, P.; Rothe, J.; Hormes, J.; Ottermann, C. R.; Bange, K.

    1995-05-01

    Thickness measurements by the method of angle-resolved, self-ratio X-ray fluorescence spectrometry (AR/SR/XFS) have been carried out on thin solid films using monochromatized synchrotron radiation at the Bonn storage ring ELSA. Synchrotron radiation was monochromatized by means of a double-crystal monochromator and fluorescence radiation was detected by a Si(Li) semiconductor detector. The results for sample systems consisting of Au on Si, Cr on SiO2 and TiO2 on alkali-free glass are very satisfactory and agree well with results obtained by other methods.

  1. Unique migration of a dental needle into the parapharyngeal space: successful removal by an intraoral approach and simulation for tracking visibility in X-ray fluoroscopy.

    Science.gov (United States)

    Okumura, Yuri; Hidaka, Hiroshi; Seiji, Kazumasa; Nomura, Kazuhiro; Takata, Yusuke; Suzuki, Takahiro; Katori, Yukio

    2015-02-01

    The first objective was to describe a novel case of migration of a broken dental needle into the parapharyngeal space. The second was to address the importance of simulation elucidating visualization of such a thin needle under X-ray fluoroscopy. Clinical case records (including computed tomography [CT] and surgical approaches) were reviewed, and a simulation experiment using a head phantom was conducted using the same settings applied intraoperatively. A 36-year-old man was referred after failure to locate a broken 31-G dental needle. Computed tomography revealed migration of the needle into the parapharyngeal space. Intraoperative X-ray fluoroscopy failed to identify the needle, so a steel wire was applied as a reference during X-ray to locate the foreign body. The needle was successfully removed using an intraoral approach with tonsillectomy under surgical microscopy. The simulation showed that the dental needle was able to be identified only after applying an appropriate compensating filter, contrasting with the steel wire. Meticulous preoperative simulation regarding visual identification of dental needle foreign bodies is mandatory. Intraoperative radiography and an intraoral approach with tonsillectomy under surgical microscopy offer benefits for accessing the parapharyngeal space, specifically for cases medial to the great vessels. © The Author(s) 2014.

  2. Effect of surface roughness on takeoff-angle-dependent X-ray fluorescence of ultrathin films at glancing incidence

    International Nuclear Information System (INIS)

    Tsuji, Kouichi; Hirokawa, Kichinosuke; Sasaki, Atsushi.

    1994-01-01

    We had previously shown that takeoff-angle-dependent X-ray fluorescence (TAD-XRF) at glancing incidence is a useful method for the characterization of thin films. Here we report the effect of surface roughness of the substrate on TAD-XRF of an ultrathin film at a glancing incidence. An optically flat glass, scratched glasses and plano-convex lenses were used as substrates. A large-range contour such as warp and a roughness of microscopic scale affect the TAD-XRF profile. Therefore, to characterize the ultrathin film by the TAD-XRF method, the material whose roughness is being investigated should be used as the substrate in TAD-XRF measurement. (author)

  3. Dose and energy dependence of response of Gafchromic XR-QA film for kilovoltage x-ray beams.

    Science.gov (United States)

    Rampado, O; Garelli, E; Deagostini, S; Ropolo, R

    2006-06-07

    There is a growing interest in Gafchromic films for patient dosimetry in radiotherapy and in radiology. A new model (XR-QA) with high sensitivity to low dose was tested in this study. The response of the film to different x-ray beam energies (range 28-145 kVp with various filtrations, dose range 0-100 mGy) and to visible light was investigated, together with the after exposure darkening properties. Exposed films were digitized with a commercially available, optical flatbed scanner. A single functional form for dose versus net pixel value variation has been determined for all the obtained calibration curves, with a unique fit parameter different for each of the used x-ray beams. The film response was dependent on beam energy, with higher colour variations for the beams in the range 80-140 kVp. Different sources of uncertainties in dose measurements, governed by the digitalization process, the film response uniformity and the calibration curve fit procedure, have been considered. The overall one-sigma dose measurement uncertainty depended on the beam energy and decreased with increasing absorbed dose. For doses above 10 mGy and beam energies in the range 80-140 kVp the total uncertainty was less than 5%, whereas for the 28 kVp beam the total uncertainty at 10 mGy was about 10%. The post-exposure colour variation was not negligible in the first 24 h after the exposure, with a consequent increase in the calculated dose of about 10%. Results of the analysis of the sensitivity to visible light indicated that a short exposure of this film to ambient and scanner light during the measurements will not have a significant impact on the radiation dosimetry.

  4. Dose and energy dependence of response of Gafchromic (registered) XR-QA film for kilovoltage x-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Rampado, O; Garelli, E; Deagostini, S; Ropolo, R [Struttura Complessa fisica Sanitaria, Azienda Ospedaliera San Giovanni Battista, Corso Bramante 88, 10126 Turin (Italy)

    2006-06-07

    There is a growing interest in Gafchromic (registered) films for patient dosimetry in radiotherapy and in radiology. A new model (XR-QA) with high sensitivity to low dose was tested in this study. The response of the film to different x-ray beam energies (range 28-145 kVp with various filtrations, dose range 0-100 mGy) and to visible light was investigated, together with the after exposure darkening properties. Exposed films were digitized with a commercially available, optical flatbed scanner. A single functional form for dose versus net pixel value variation has been determined for all the obtained calibration curves, with a unique fit parameter different for each of the used x-ray beams. The film response was dependent on beam energy, with higher colour variations for the beams in the range 80-140 kVp. Different sources of uncertainties in dose measurements, governed by the digitalization process, the film response uniformity and the calibration curve fit procedure, have been considered. The overall one-sigma dose measurement uncertainty depended on the beam energy and decreased with increasing absorbed dose. For doses above 10 mGy and beam energies in the range 80-140 kVp the total uncertainty was less than 5%, whereas for the 28 kVp beam the total uncertainty at 10 mGy was about 10%. The post-exposure colour variation was not negligible in the first 24 h after the exposure, with a consequent increase in the calculated dose of about 10%. Results of the analysis of the sensitivity to visible light indicated that a short exposure of this film to ambient and scanner light during the measurements will not have a significant impact on the radiation dosimetry.

  5. Induction of strand breaks in DNA films by low energy electrons and soft X-ray under nitrous oxide atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Elahe, E-mail: Elahe.Alizadeh@USherbrooke.ca [Groupe en science des radiations, Departement de medecine nucleaire et radiobiologie, Faculte de medecine et des sciences de la sante, Universite de Sherbrooke, Sherbrooke, J1H 5N4 (Canada); Sanche, Leon, E-mail: Leon.Sanche@USherbrooke.ca [Groupe en science des radiations, Departement de medecine nucleaire et radiobiologie, Faculte de medecine et des sciences de la sante, Universite de Sherbrooke, Sherbrooke, J1H 5N4 (Canada)

    2012-01-15

    Five-monolayer (5 ML) plasmid DNA films deposited on glass and tantalum substrates were exposed to Al K{sub {alpha}} X-rays of 1.5 keV under gaseous nitrous oxide (N{sub 2}O) at atmospheric pressure and temperature. Whereas the damage yields for DNA deposited on glass are due to soft X-rays, those arising from DNA on tantalum are due to both the interaction of low energy photoelectrons from the metal and X-rays. Then, the differences in the yields of damage on glass and tantalum substrates, essentially arises from interaction of essentially low-energy electrons (LEEs) with DNA molecules and the surrounding atmosphere. The G-values (i.e., the number of moles of product per Joule of energy absorbed) for DNA strand breaks induced by LEEs (G{sub LEE}) and the lower limit of G-values for soft X-ray photons (G{sub XL}) were calculated and the results compared to those from previous studies under atmospheric conditions and other ambient gases, such as N{sub 2} and O{sub 2}. Under N{sub 2}O, the G-values for loss of supercoiled DNA are 103{+-}15 nmol/J for X-rays, and 737{+-}110 nmol/J for LEEs. Compared to corresponding values in an O{sub 2} atmosphere, the effectiveness of X-rays to damage DNA in N{sub 2}O is less, but the G value for LEEs in N{sub 2}O is more than twice the corresponding value for an oxygenated environment. This result indicates a higher effectiveness for LEEs relative to N{sub 2} and O{sub 2} environments in causing SSB and DSB in an N{sub 2}O environment. Thus, the previously observed radiosensitization of cells by N{sub 2}O may not be only due to OH{sup {center_dot}} radicals but also to the reaction of LEE with N{sub 2}O molecules near DNA. The previous experiments with N{sub 2} and O{sub 2} and the present one demonstrate the possibility to investigate damage induced by LEEs to biomolecules under various types of surrounding atmospheres. - Highlights: > A completely different and new approach is applied to investigate the radiation chemistry of N

  6. ESR and X-ray diffraction studies on thin films of poly-3-hexylthiophene: Molecular orientation and magnetic interactions

    International Nuclear Information System (INIS)

    Sugiyama, Keisuke; Kojima, Takashi; Fukuda, Hisashi; Yashiro, Hisashi; Matsuura, Toshihiko; Shimoyama, Yuhei

    2008-01-01

    Poly-3-hexylthiophene (P3HT) thin films were investigated by X-ray diffraction (XRD) and electron spin resonance (ESR) to reveal the film structure and molecular organization. The XRD data showed a diffraction pattern with a plane separation between the planes containing thiophene rings of 16.0 A. Comparison between the XRD patterns of powder and thin films of P3HT suggests that the main chains are folded on the substrate. Angular variation of the line position (g-value) of ESR spectra revealed that thiophene ring of P3HT orients along the substrate normal axis. The ESR linewidth varied by the angular rotation, indicating the one-dimensional spin-chain interactions in the P3HT thin films with a linear network of spin-chains. An organic thin-film transistor (OTFT) with P3HT film as a channel layer was then demonstrated. The P3HT films showed conducting characteristics with holes as carriers. The OTFTs indicated a field-effect mobility of 4.93 x 10 -3 cm 2 /Vs and an on/off ratio of 73 in the accumulation mode

  7. Examination of the X-ray piping diagnostic system using EGS4 (examination of the film and iron rust)

    International Nuclear Information System (INIS)

    Kajiwara, G.

    2000-01-01

    In the X-ray piping diagnosis system, X-ray photograph is taken of the used pipes, and from the density of the image of the pipe on the film, the thickness of the pipe wall is measured using the relationship between the density and the thickness. First, as for the relationship between the absorbed energy and the density on the film, though good agreement was obtained last year, it is improved further by making energy bin smaller in the calculation of EGS4. The reason of the agreement was researched and understood. Next, using EGS4, the calculation of the thickness of the steel was carried out which was covered with the rust, using the element analysis result of the rust sample that was collected in the old pipe. When the thickness changes, the rate of the energy absorption of the steel and the rust layer changes. This relationship between the energy absorption and the thickness of the layers is expressed approximately in a formula. It will be reflected on the diagnosis of the pipes. (author)

  8. Feasibility of X-ray analysis of multi-layer thin films at a single beam voltage

    International Nuclear Information System (INIS)

    Statham, P J

    2010-01-01

    Multi-layer analysis using electron beam excitation and X-ray spectrometry is a powerful tool for characterising layers down to 1 nm thickness and with typically 1 μm lateral resolution but does not always work. Most published applications have used WDS with many measurements at different beam voltages and considerable experience has been needed to choose lines and voltages particularly for complex multi-layer problems. A new objective mathematical approach is described which demonstrates whether X-ray analysis can obtain reliable results for an arbitrary multi-layer problem. A new algorithm embodied in 'ThinFilmID' software produces a single plot that shows feasibility of achieving results with a single EDS spectrum and suggests the optimal beam voltage. Synthesis of EDS spectra allows the precision in results to be estimated and acquisition conditions modified before wasting valuable instrument time. Thus, practicality of multi-layer thin film analysis at a single beam voltage can now be established without the extensive experimentation that was previously required by a microanalysis expert. Examples are shown where the algorithm discovers viable single-voltage conditions for applications that experts previously thought could only be addressed using measurements at more than one beam voltage.

  9. Point defects in lithium fluoride films for micro-radiography, X-ray microscopy and photonic applications

    Energy Technology Data Exchange (ETDEWEB)

    Bonfigli, F.; Flora, F.; Marolo, T.; Montereali, R.M.; Baldacchini, G. [ENEA, UTS Tecnologie Fisiche Avanzate, C.R. Frascati, Via E. Fermi, 45, 00044 Frascati (Rome) (Italy); Faenov, A.Ya.; Pikuz, T.A. [MISDC of VNIIFTRI Mendeleevo, Moscow region, 141570 (Russian Federation); Nichelatti, E. [ENEA, UTS Tecnologie Fisiche Avanzate, C.R. Casaccia, Via Anguillarese, 301, 00060 Santa Maria di Galeria (Rome) (Italy); Reale, L. [Universita dell' Aquila e INFN, Dip. di Fisica, Coppito, L' Aquila (Italy)

    2005-01-01

    Point defects in lithium fluoride (LiF) have recently attracted renewed attention due the exciting results obtained in the realisation of miniaturised optical devices. Among light-emitting materials, LiF is of particular interest because it is almost not hygroscopic and can host, even at room temperature, stable color centers (CCs) that emit light in the visible and in the near infrared spectral range under optical excitation. The increasing demand for low-dimensionality photonic devices imposes the use of advanced irradiation methods for producing luminescent structures with high spatial resolution. An innovative irradiation technique to produce luminescent CCs in LiF crystals and films by using an extreme ultra-violet and soft X-ray laser-plasma source will be presented. This technique is capable to induce colored patterns with submicrometric spatial resolution on large areas in a short exposure time as compared with other irradiation methods. Luminescent regular arrays produced by this irradiation technique will be shown. Recently, the idea of using a LiF film as image detector for X-ray microscopy and micro-radiography based on optically-stimulated luminescence from CCs has been developed. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Determination of wafer bonding mechanisms for plasma activated SiN films with x-ray reflectivity

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, S [Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095 (United States); Sandhu, R [Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095 (United States); Wojtowicz, M [Northrop Grumman Space Technology, Redondo Beach, CA 90278 (United States); Sun, Y [Department of Chemical Engineering, University of California, Los Angeles, CA 90095 (United States); Hicks, R [Department of Chemical Engineering, University of California, Los Angeles, CA 90095 (United States); Goorsky, M S [Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095 (United States)

    2005-05-21

    Specular and diffuse x-ray reflectivity measurements were employed for wafer bonding studies of surface and interfacial reactions in {approx}800 A thick SiN films deposited on III-V substrates. CuK{sub {alpha}}{sub 1} radiation was employed for these measurements. The as-deposited films show very low surface roughness and uniform, high density SiN. Reflectivity measurements show that an oxygen plasma treatment converts the nitride surface to a somewhat porous SiO{sub x} layer (67 A thick, at 80% of SiO{sub 2} density), with confirmation of the oxide formation from x-ray photoelectron spectroscopy. Reactions at the bonded interface of two oxygen plasma treated SiN layers were examined using a bonded structure from which one of the III-V wafers is removed. Reflectivity measurements of bonded structures annealed at 150 deg. C and 300 deg. C show an increase in the SiO{sub x} layer density and thickness and even a density gradient across this interface. The increase in density is correlated with an increase in bond strength, where after the 300 deg. C anneal, a high interfacial bond strength, exceeding the bulk strength, was achieved.

  11. On revealing the vertical structure of nanoparticle films with elemental resolution: A total external reflection X-ray standing waves study

    Energy Technology Data Exchange (ETDEWEB)

    Zargham, Ardalan, E-mail: zargham@ifp.uni-bremen.d [Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen (Germany); Schmidt, Thomas; Flege, Jan Ingo; Sauerbrey, Marc; Hildebrand, Radowan [Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen (Germany); Roehe, Sarah; Baeumer, Marcus [Applied and Physical Chemistry, University of Bremen, Leobener Str. 2, 28359, Bremen (Germany); Falta, Jens [Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen (Germany)

    2010-02-15

    We present a promising combination of methods to precisely determine the morphology of nanostructures, drawing on the example of monodisperse CoPt{sub 3} nanoparticle films deposited by spin coating and dip coating techniques on functionalized Au substrates. Ex-situ X-ray standing waves in total external reflection combined with X-ray reflectivity measurements were employed to determine element-specific atomic-density distributions in vertical direction.

  12. X-ray exposures given with various combinations of film and screen

    International Nuclear Information System (INIS)

    Schlenker, R.A.; Kirsh, I.E.

    A comparison of entrance exposure doses of patients for various film and screen combinations and xeroradiographs showed that moderate speed screen and film gave exposures 4 to 7 times greater than fast film and screen and that xeroradiographs produced exposures 20 to 40 times greater than fast film and screen. Xeroradiographs produced table top incident exposures which exceeded Illinois Department of Health limits, while conventional film-screen combinations did not. (U.S.)

  13. Investigation of the structure of human dental tissue at multiple length scales using high energy synchrotron X-ray SAXS/WAXS

    Science.gov (United States)

    Sui, Tan; Landini, Gabriel; Korsunsky, Alexander M.

    2011-10-01

    High energy (>50keV) synchrotron X-ray scattering experiments were carried out on beamline I12 JEEP at the Diamond Light Source (DLS, Oxford, UK). Although a complete human tooth could be studied, in the present study attention was focused on coupons from the region of the Dentin-Enamel Junction (DEJ). Simultaneous high energy SAXS/WAXS measurements were carried out. Quantitative analysis of the results allows multiple length scale characterization of the nano-crystalline structure of dental tissues. SAXS patterns analysis provide insight into the mean thickness and orientation of hydroxyapatite particles, while WAXS (XRD) patterns allow the determination of the crystallographic unit cell parameters of the hydroxyapatite phase. It was found that the average particle thickness determined from SAXS interpretation varies as a function of position in the vicinity of the DEJ. Most mineral particles are randomly orientated within dentin, although preferred orientation emerges and becomes stronger on approach to the enamel. Within the enamel, texture is stronger than anywhere in the dentin, and the determination of lattice parameters can be accomplished by Pawley refinement of the multiple peak diffraction pattern. The results demonstrate the feasibility of using high energy synchrotron X-ray beams for the characterization of human dental tissues. This opens up the opportunity of studying thick samples (e.g., complete teeth) in complex sample environments (e.g., under saline solution). This opens new avenues for the application of high energy synchrotron X-ray scattering to dental research.

  14. Observation of superheavy primary cosmic ray nuclei with solid state track detectors and x-ray films

    International Nuclear Information System (INIS)

    Doke, Tadayoshi; Hayashi, Takayoshi; Ito, Kensai; Yanagimachi, Tomoki; Kobayashi, Shigeru.

    1977-01-01

    The measurements of energy spectra and the nuclear charge distribution of superheavy nuclei heavier than iron in primary cosmic ray can provide information on the origin, propagation and life time of the cosmic ray. Since incident particles are in the region of relativistic velocity (the low energy cosmic ray below the cutoff energy is forbidden from entering), the charges of cosmic ray nuclei can be determined without knowing the energy of particles. The balloon-borne solid state track detector and plastic and X-ray films were employed for the detection of superheavy cosmic ray, and the five events were detected with the cellulose nitrate film. The flux of superheavy nuclei is predicted from the present analysis. (Yoshimori, M.)

  15. X-ray spectroscopy study of electronic structure of laser-irradiated Au nanoparticles in a silica film

    International Nuclear Information System (INIS)

    Jonnard, P.; Bercegol, H.; Lamaignere, L.; Morreeuw, J.-P.; Rullier, J.-L.; Cottancin, E.; Pellarin, M.

    2005-01-01

    The electronic structure of gold nanoparticles embedded in a silica film is studied, both before and after irradiation at 355 nm by a laser. The Au 5d occupied valence states are observed by x-ray emission spectroscopy. They show that before irradiation the gold atoms are in metallic states within the nanoparticles. After irradiation with a fluence of 0.5 J/cm 2 , it is found that gold valence states are close to those of a metal-poor gold silicide; thanks to a comparison of the experimental Au 5d states with the calculated ones for gold silicides using the density-functional theory. The formation of such a compound is driven by the diffusion of the gold atoms into the silica film upon the laser irradiation. At higher fluence, 1 J/cm 2 , we find a higher percentage of metallic gold that could be attributed to annealing in the silica matrix

  16. Heterogeneous local order in self-assembled nanoparticle films revealed by X-ray cross-correlations

    Directory of Open Access Journals (Sweden)

    Felix Lehmkühler

    2018-05-01

    Full Text Available We report on the self-assembly of gold nanoparticles coated with a soft poly(ethylene glycol shell studied by X-ray cross-correlation analysis. Depending on the initial concentration of gold nanoparticles used, structurally heterogeneous films were formed. The films feature hot spots of dominating four- and sixfold local order with patch sizes of a few micrometres, containing 104–105 particles. The amplitude of the order parameters suggested that a minimum sample amount was necessary to form well ordered local structures. Furthermore, the increasing variation in order parameters with sample thickness demonstrated a high degree of structural heterogeneity. This wealth of information cannot be obtained by the conventional microscopy techniques that are commonly used to study nanocrystal superstructures, as illustrated by complementary scanning electron microscopy measurements.

  17. Laser-induced surface recrystallization of polycrystalline PbI2 thick films for X-ray detector application

    Science.gov (United States)

    Sun, Hui; Zhao, Beijun; Zhu, Xinghua; Zhu, Shifu; Yang, Dingyu; Wangyang, Peihua; Gao, Xiuyin

    2018-01-01

    In this work, laser-induced surface recrystallization process was developed to improve the surface properties and device performance of the polycrystalline PbI2 thick films prepared by using close space vapor deposition method. A continuous polycrystalline PbI2 recrystallized layer with a better mechanical strength and reflectivity improved from 2% to 4%-6% was obtained by this recrystallization process for the films with mechanical pretreatment. Other polytypes is absent in the recrystallized layer with the 2H-polytype remaining before and after treatment and obtaining improved electrical and X-ray photoelectric response performance. The pretreatment such as mechanical cutting/polishing and hydrogenation is necessary to lower the non-wetting crystallization behavior during the recrystallization process due to the rough surface state and oxygen contamination.

  18. Sulfur X-ray absorption fine structure in porous Li–S cathode films measured under argon atmospheric conditions

    International Nuclear Information System (INIS)

    Müller, Matthias; Choudhury, Soumyadip; Gruber, Katharina; Cruz, Valene B.; Fuchsbichler, Bernd; Jacob, Timo; Koller, Stefan; Stamm, Manfred; Ionov, Leonid; Beckhoff, Burkhard

    2014-01-01

    In this paper we present the first results for the characterization of highly porous cathode materials with pore sizes below 1 μm for Lithium Sulfur (Li–S) batteries by Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy. A novel cathode material of porous carbon films fabricated with colloidal array templates has been investigated. In addition, an electrochemical characterization has been performed aiming on an improved correlation of physical and chemical parameters with the electrochemical performance. The performed NEXAFS measurements of cathode materials allowed for a chemical speciation of the sulfur content inside the cathode material. The aim of the presented investigation was to evaluate the potential of the NEXAFS technique to characterize sulfur in novel battery material. The long term goal for the characterization of the battery materials is the sensitive identification of undesired side reactions, such as the polysulfide shuttle, which takes place during charging and discharging of the battery. The main drawback associated with the investigation of these materials is the fact that NEXAFS measurements can usually only be performed ex situ due to the limited in situ instrumentation being available. For Li–S batteries this problem is more pronounced because of the low photon energies needed to study the sulfur K absorption edge at 2472 eV. We employed 1 μm thick Si 3 N 4 windows to construct sealed argon cells for NEXAFS measurements under ultra high vacuum (UHV) conditions as a first step towards in situ measurements. The cells keep the sample under argon atmosphere at any time and the X-ray beam passes mainly through vacuum which enables the detection of the low energy X-ray emission of sulfur. Using these argon cells we found indications for the presence of lithium polysulfides in the cathode films whereas the correlations to the offline electrochemical results remain somewhat ambiguous. As a consequence of these findings one may

  19. Assessment of dose to patients undergoing computed radiography and film screen x-ray examinations in some Khartoum Hospitals

    International Nuclear Information System (INIS)

    Mohamed Khair, Haiffa Daffa Allah Mustafa

    2015-12-01

    Medical ionizing radiation sources give by far the largest contribution to the population dose from man made sources and most of the contribution comes from diagnostic x-rays. The optimization principle of radiation protection requires the minimization of radiation dose to patients while acquiring diagnostic quality images in radiology. In radiography, the extent of patient dose reduction is limited by the characteristics of the system used and the quality (or penetrating ability) of the x-ray beam. In this study, the entrance surface air kerma doses (ESA Ks) to patients undergoing 7 selected x-ray examinations were estimated. The study was conducted in eight hospitals in Khartoum State, comprising nine x-ray units and a total of 1200 patients were involved. Four of the hospitals involved in this study use computed radiography (CR) technology while the other four use film screen (FS) technology. The selected examinations were, abdomen (AP), chest (PA), pelvis (AP), skull (AP/PA), skull (LAT), thoracic spine (AP) and thoracic spine (LAT). The entrance surface air kerma was calculated by two methods, utilizing software CAL Dose X-3.5 and a mathematical model. Average ESAK values calculated using the two methods for hospitals using (CR) technology in mGy were 2.99 and 2.98, 0.34 and 0.31, 2.79 and 2.58, 0.76 and 0.71, 0.94 and 0.79, 3.4 and 3,2 and 5.9 and 5.03, for the above mentioned selected investigations respectively. And average ESAK values calculated using two methods for hospital using FS technology in mGy were found 4.98 and 4.19, 0.37 and 0.34, 4.15 and 3.95, 2.2 and 2. 1.3 and 1.1, 3.9 and 3.9, 9.4 and 8.3 for the above mentioned selected investigations respectively. Average ESAK values obtained by two methods for FS were higher values than the obtained by CR by 37 and 29%, 50 and 25%, 8%, 32 and 34%, 65 and 64%, 27 and 28%, 12% and 73% and 39% for the above mentioned selected investigations, respectively. This shows that CR technique allows diagnostically

  20. Thickness measurement of SiO2 films thinner than 1 nm by X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Joong Kim, Kyung; Park, Ki Tae; Lee, Jong Wan

    2006-01-01

    The thickness measurement of ultra-thin SiO 2 films thinner than 1 nm was studied by X-ray photoelectron spectroscopy (XPS). Amorphous SiO 2 thin films were grown on amorphous Si films to avoid the thickness difference due to the crystalline structure of a substrate. SiO 2 thin films were grown by ion beam sputter deposition under oxygen gas flow and the thickness was measured by in situ XPS. The attenuation length was determined experimentally by a SiO 2 film with a known thickness. The straight line fit between the measured thickness using XPS and the nominal thickness showed a good linear relation with a gradient of 0.969 and a small offset of 0.126 nm. The gradient measured at the range of 3.4-0.28 nm was very close to that measured at sub-nanometer range of 1.13-0.28 nm. This result means that the reliable measurement of SiO 2 film thickness below 1 nm is possible by XPS

  1. Thickness measurement of a thin hetero-oxide film with an interfacial oxide layer by X-ray photoelectron spectroscopy

    Science.gov (United States)

    Kim, Kyung Joong; Lee, Seung Mi; Jang, Jong Shik; Moret, Mona

    2012-02-01

    The general equation Tove = L cos θ ln(Rexp/R0 + 1) for the thickness measurement of thin oxide films by X-ray photoelectron spectroscopy (XPS) was applied to a HfO2/SiO2/Si(1 0 0) as a thin hetero-oxide film system with an interfacial oxide layer. The contribution of the thick interfacial SiO2 layer to the thickness of the HfO2 overlayer was counterbalanced by multiplying the ratio between the intensity of Si4+ from a thick SiO2 film and that of Si0 from a Si(1 0 0) substrate to the intensity of Si4+ from the HfO2/SiO2/Si(1 0 0) film. With this approximation, the thickness levels of the HfO2 overlayers showed a small standard deviation of 0.03 nm in a series of HfO2 (2 nm)/SiO2 (2-6 nm)/Si(1 0 0) films. Mutual calibration with XPS and transmission electron microscopy (TEM) was used to verify the thickness of HfO2 overlayers in a series of HfO2 (1-4 nm)/SiO2 (3 nm)/Si(1 0 0) films. From the linear relation between the thickness values derived from XPS and TEM, the effective attenuation length of the photoelectrons and the thickness of the HfO2 overlayer could be determined.

  2. Structural study of thin films prepared from tungstate glass matrix by Raman and X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Montanari, Bianca; Barbosa, Anne J.; Ribeiro, Sidney J.L.; Messaddeq, Younes [Departamento de Quimica Geral e Inorganica, Instituto de Quimica, UNESP, CP 355, CEP 14800-900 Araraquara, SP (Brazil); Poirier, Gael [Departamento de Ciencias Exatas, UNIFAL-MG, CEP 37130-000 Alfenas, MG (Brazil)], E-mail: gael@unifal-mg.edu.br; Li, Maximo S. [Instituto de Fisica, USP, CP 369, CEP 13560-970 Sao Carlos, SP (Brazil)

    2008-06-30

    Thin films were prepared using glass precursors obtained in the ternary system NaPO{sub 3}-BaF{sub 2}-WO{sub 3} and the binary system NaPO{sub 3}-WO{sub 3} with high concentrations of WO{sub 3} (above 40% molar). Vitreous samples have been used as a target to prepare thin films. Such films were deposited using the electron beam evaporation method onto soda-lime glass substrates. Several structural characterizations were performed by Raman spectroscopy and X-ray Absorption Near Edge Spectroscopy (XANES) at the tungsten L{sub I} and L{sub III} absorption edges. XANES investigations showed that tungsten atoms are only sixfold coordinated (octahedral WO{sub 6}) and that these films are free of tungstate tetrahedral units (WO{sub 4}). In addition, Raman spectroscopy allowed identifying a break in the linear phosphate chains as the amount of WO{sub 3} increases and the formation of P-O-W bonds in the films network indicating the intermediary behavior of WO{sub 6} octahedra in the film network. Based on XANES data, we suggested a new attribution of several Raman absorption bands which allowed identifying the presence of W-O{sup -} and W=O terminal bonds and a progressive apparition of W-O-W bridging bonds for the most WO{sub 3} concentrated samples (above 40% molar) attributed to the formation of WO{sub 6} clusters.

  3. Use of alpha-particle excited x-rays to measure the thickness of thin films containing low-Z elements

    International Nuclear Information System (INIS)

    Hanser, F.A.; Sellers, B.; Ziegler, C.A.

    1976-01-01

    The thickness of thin surface films containing low Z elements can be determined by measuring the K X-ray yields from alpha particle excitation. The samples are irradiated in a helium atmosphere by a 5 mCi polonium-210 source, and the low energy X-rays detected by a flow counter with a thin-stretched polypropylene window. The flow counter output is pulse height sorted by a single channel analyzer (SCA) and counted to give the X-ray yield. Best results have been obtained with Z = 6 to 9 (C, N, O, and F), but usable yields are obtained even for Z = 13 or 14 (Al and Si). The low energy of the X-rays (0.28 to 1.74 keV) limits the method to films of several hundred nm thickness or less and to situations where the substrate does not produce interfering X-rays. It is possible to determine the film thickness with 50 percent accuracy by direct calculation using the measured alpha-particle spectrum and known or calculated K X-ray excitation cross sections. By calibration with known standards the accuracy can be increased substantially. The system has thus far been applied to SiO 2 on Si, Al 2 O 3 on Al, and CH 2 on Al

  4. X-ray diffraction stress analysis of interrupted titanium nitride films: Combining the sin2ψ and crystallite group methods

    International Nuclear Information System (INIS)

    Sinkovits, Theo; Zhao, Yue; O'Brien, Rebecca; Dowey, Steve

    2014-01-01

    Interruptions during film growth have been discussed by researchers to assist in understanding the evolution of stress in physical vapour deposition films. A change in intrinsic stress is directly related to microstructure, hence careful analysis of stress in films can provide valuable structure–stress correlated information. In this study we discuss the use of combining two X-ray diffraction (XRD) stress analysis methods to elucidate the effect of interruptions during growth on the residual stress of TiN films. The sin 2 ψ and crystallite group method (CGM), scanning the (220) peaks from all grains in the film and only (111) oriented crystallites respectively, were used to analyse residual stress in standard and interrupted cathodic arc TiN films 1.5, 3.5 and 6.5 μm thick, grown on high-speed steel substrates. The sin 2 ψ method does not reveal any changes in stress with interruptions, however, measurements using the CGM show increased compressive stress and increased a 0 in the resultant TiN films. A comparison of results from both XRD methods indicates that an increased compressive stress from interruptions could be due to an increased number of defects in (111) oriented grains during the interruptions which would also affect a 0 as evident. In both methods, compressive stresses are found to decrease with increased thickness of films. - Highlights: • Interrupting TiN film growth increases compressive stress in (111) grains. • Increased stress is believed to be caused by defects incorporated into or not annealed out of (111) grains. • A comparison of sin 2 ψ and CGM results reveals differences in stress. • Compressive stress decreases as TiN films increase in thickness from 1.5 μm to 6.5 μm

  5. Application of in-plane x-ray diffraction technique for residual stress measurement of TiN film/WC-Co alloy

    International Nuclear Information System (INIS)

    Takago, Shigeki; Yasui, Haruyuki; Awazu, Kaoru; Sasaki, Toshihiko; Hirose, Yukio; Sakurai, Kenji

    2006-01-01

    An in-plane X-ray diffraction technique was used to measure the residual stress of a CVD (chemical vapor deposition) TiN-coated WC-Co alloy. We could obtain the diffraction pattern from a thin film layer, eliminating that of the substrate. In the case of a conventional X-ray diffractometer, the X-ray penetration depth is about few μm. However, for a grazing incidence beam it is only 0.2μm. Depth profiles of residual stress in TiN film layer were evaluated by the present method and the conventional sin 2 ψ technique. We concluded that the in-plane diffraction technique enables us to determine the residual stress in a DVD-TiN film having an oriented texture. It was found that the residual tensile stress generated a mismatch of the coefficient of thermal expansion between the film and the substrate. (author)

  6. Application of in-plane x-ray diffraction technique for residual stress measurement of TiN film/WC-Co alloy

    Energy Technology Data Exchange (ETDEWEB)

    Takago, Shigeki; Yasui, Haruyuki; Awazu, Kaoru [Industrial Research Inst. of Ishikawa, Kanazawa, Ishikawa (Japan); Sasaki, Toshihiko; Hirose, Yukio [Kanazawa Univ., Dept. of Materials Science and Engineering, Kanazawa, Ishikawa (Japan); Sakurai, Kenji [National Inst. for Materials Science, Tsukuba, Ibaraki (Japan)

    2006-06-15

    An in-plane X-ray diffraction technique was used to measure the residual stress of a CVD (chemical vapor deposition) TiN-coated WC-Co alloy. We could obtain the diffraction pattern from a thin film layer, eliminating that of the substrate. In the case of a conventional X-ray diffractometer, the X-ray penetration depth is about few {mu}m. However, for a grazing incidence beam it is only 0.2{mu}m. Depth profiles of residual stress in TiN film layer were evaluated by the present method and the conventional sin{sup 2}{psi} technique. We concluded that the in-plane diffraction technique enables us to determine the residual stress in a DVD-TiN film having an oriented texture. It was found that the residual tensile stress generated a mismatch of the coefficient of thermal expansion between the film and the substrate. (author)

  7. An audit of rejected repeated x-ray films as a quality assurance element in a radiology department.

    Science.gov (United States)

    Eze, K C; Omodia, N; Okegbunam, B; Adewonyi, T; Nzotta, C C

    2008-12-01

    To find out the causes, number, percentage and sizes of rejected radiographic films with a view of adopting measures that will reduce the rate and number of rejected films. Radiology Department of a University Teaching Hospital. Over a two-year period (1st April 2002 to 31st March 2004), the total number of x-ray films utilized for radiographic examinations, rejected films and sizes of rejected films were collected retrospectively from the medical record of radiology department. All the rejected films were viewed by a radiologist and three radiographers for the causes of the rejects which was arrived at by consensus. The data was analysed. A total of 15,095 films were used in the study period and 1,338 films (8.86%) were rejected or wasted. The rate of rejected films varied from 7.69% to 13.82% with average of 8.86%. The greatest cause of film rejects was radiographers' faults 547 (40.88%), followed by equipments faults 255 (19.06%), and patients' faults 250 (18.90%). The highest reject rate (13.82%) was for films used for examination of the spine (15 x 30) cm size. This is followed by 9.92% for skull (18 x 24) cm films and 8.83% for small sized films (24 x 30) cm used for paediatric patients. Of a total of 1,338 rejected films, 1276 (95.37%) additional exposure were done to obtain the basic desired diagnostic information involving 1151 patients; 885 (76.89%) of these patients needed at least one additional hospital visit to take the repeat exposure. Rejected films are not billable; patients receive additional radiation and may even come to hospital in another day for the repeat. Radiographer's work is increased as well as that of the support staff. The waiting room may be congested and waiting time increased. The cost of processing chemical and films are increased, thus if work is quantified in monetary terms, the cost of repeats is high. Rejected-repeated film analysis is cheap, simple, practicable, easy to interpret and an effective indictor of quality assurance

  8. Correcting and coating thin walled X-ray Optics via a combination of controlled film deposition and magnetic smart materials

    Science.gov (United States)

    Ulmer, Melville

    The project goal is to demonstrate that thin walled (price. Since the desired surface area for the next generation X-ray telescope is >10x that of Chandra, the >10x requirement is then for >200 m^2 of surface area with a surface finish of better than 0.5 nm. Therefore, replication of some sort is called for. Because no replication technology has been shown to achieve ≤1" angular resolution, post fabrication figure corrections are likely going to be necessary. Some have proposed to do this in orbit and others prelaunch including us. Our prelaunch approach is to apply in-plane stresses to the thin walled mirror shells via a magnetic field. The field will be held in by some magnetically hard material such as NiCo. By use of a so called magnetic smart material (MSM) such as Terfenol-D, we already shown that strong enough stresses can be generated. Preliminary work has also shown that the magnetic field can be held in well enough to apply the figure correcting stresses pre-launch. What we call "set-it and forget-it." However, what is unique about our approach is that at the cost of complexity and some areal coverage, our concept will also accommodate in-orbit adjustments. Furthermore, to the best of our knowledge ours is one of two known stress modification processes that are bi-axial. Our plan is first to validate set-it and forget-it first on cantilevers and then to expand this to working on 5 cm x 5 cm pieces. We will work both with NiCo and glass or Si coated with Terfenol-D. Except for the NiCo, substrates we will also coat the samples with NiCo in order to have a film that will hold in the magnetic field. As part of the coating process, we will control the stress of the film by varying the voltage bias while coating. The bias stress control can be used to apply films with minimal stress such as Terfenol-D and X-ray reflecting coatings such as Ir. Ir is a highly desirable coating for soft X-ray astronomy mirrors that can have significant built in stress unless

  9. Dental x-rays

    Science.gov (United States)

    ... Aps JK. Radiographic techniques. In: Dean JA, ed. McDonald and Avery's Dentistry for the Child and Adolescent . ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  10. Hard X-ray photoelectron spectroscopy of bulk and thin films of Heusler compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kozina, Xeniya

    2012-03-26

    X-ray photoemission spectroscopy (XPS) is one of the most universal and powerful tools for investigation of chemical states and electronic structures of materials. The application of hard X-rays increases the inelastic mean free path of the emitted electrons within the solid and thus makes hard X-ray photoelectron spectroscopy (HAXPES) a bulk sensitive probe for solid state research and especially a very effective nondestructive technique to study buried layers. This thesis focuses on the investigation of multilayer structures, used in magnetic tunnel junctions (MTJs), by a number of techniques applying HAXPES. MTJs are the most important components of novel nanoscale devices employed in spintronics. The investigation and deep understanding of the mechanisms responsible for the high performance of such devices and properties of employed magnetic materials that are, in turn, defined by their electronic structure becomes feasible applying HAXPES. Thus the process of B diffusion in CoFeB-based MTJs was investigated with respect to the annealing temperature and its influence on the changes in the electronic structure of CoFeB electrodes that clarify the behaviour and huge TMR ratio values obtained in such devices. These results are presented in chapter 6. The results of investigation of the changes in the valence states of buried off-stoichiometric Co{sub 2}MnSi electrodes were investigated with respect to the Mn content {alpha} and its influence on the observed TMR ratio are described in chapter 7. Magnetoelectronic properties such as exchange splitting in ferromagnetic materials as well as the macroscopic magnetic ordering can be studied by magnetic circular dichroism in photoemission (MCDAD). It is characterized by the appearance of an asymmetry in the photoemission spectra taken either from the magnetized sample with the reversal of the photon helicity or by reversal of magnetization direction of the sample when the photon helicity direction is fixed. Though

  11. Study of surface cleaning methods and pyrolysis temperatures on nanostructured carbon films using x-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kerber, Pranita; Porter, Lisa M.; McCullough, Lynne A.; Kowalewski, Tomasz; Engelhard, Mark; Baer, Donald [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Chemistry Department, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States)

    2012-11-15

    Nanostructured carbon (ns-C) films fabricated by stabilization and pyrolysis of diblock copolymers are of interest for a variety of electrical/electronic applications due to their chemical inertness, high-temperature insensitivity, very high surface area, and tunable electrical resistivity over a wide range [Kulkarni et al., Synth. Met. 159, 177 (2009)]. Because of their high porosity and associated high specific surface area, controlled surface cleaning studies are important for fabricating electronic devices from these films. In this study, quantification of surface composition and surface cleaning studies on ns-C films synthesized by carbonization of diblock copolymers of polyacrylonitrile-b-poly(n-butyl acrylate) at two different temperatures were carried out. X-ray photoelectron spectroscopy was used for elemental analysis and to determine the efficacy of various surface cleaning methods for ns-C films and to examine the polymer residues in the films. The in-situ surface cleaning methods included HF vapor treatment, vacuum annealing, and exposure to UV-ozone. Quantitative analysis of high-resolution XPS scans showed 11 at. % nitrogen was present in the films pyrolyzed at 600 Degree-Sign C, suggesting incomplete denitrogenation of the copolymer films. The nitrogen atomic concentration decreased significantly for films pyrolyzed at 900 Degree-Sign C confirming extensive denitrogenation at that temperature. Furthermore, quantitative analysis of nitrogen subpeaks indicated higher loss of nitrogen atoms residing at the edge of graphitic clusters relative to that of nitrogen atoms within the graphitic clusters, suggesting higher graphitization with increasing pyrolysis temperature. Of the surface cleaning methods investigated, in-situ annealing of the films at 300 Degree-Sign C for 40 min was found to be the most efficacious in removing adventitious carbon and oxygen impurities from the surface.

  12. Porous plug phase separator and superfluid film flow suppression system for the soft x-ray spectrometer onboard Hitomi

    Science.gov (United States)

    Ezoe, Yuichiro; DiPirro, Michael; Fujimoto, Ryuichi; Ishikawa, Kumi; Ishisaki, Yoshitaka; Kanao, Kenichi; Kimball, Mark; Mitsuda, Kazuhisa; Mitsuishi, Ikuyuki; Murakami, Masahide; Noda, Hirofumi; Ohashi, Takaya; Okamoto, Atsushi; Satoh, Yohichi; Sato, Kosuke; Shirron, Peter; Tsunematsu, Shoji; Yamaguchi, Hiroya; Yoshida, Seiji

    2018-01-01

    When using superfluid helium in low-gravity environments, porous plug phase separators are commonly used to vent boil-off gas while confining the bulk liquid to the tank. Invariably, there is a flow of superfluid film from the perimeter of the porous plug down the vent line. For the soft x-ray spectrometer onboard ASTRO-H (Hitomi), its approximately 30-liter helium supply has a lifetime requirement of more than 3 years. A nominal vent rate is estimated as ˜30 μg/s, equivalent to ˜0.7 mW heat load. It is, therefore, critical to suppress any film flow whose evaporation would not provide direct cooling of the remaining liquid helium. That is, the porous plug vent system must be designed to both minimize film flow and to ensure maximum extraction of latent heat from the film. The design goal for Hitomi is to reduce the film flow losses to knife-edge devices. Design, on-ground testing results, and in-orbit performance are described.

  13. Residual stress mapping by micro X-ray diffraction: Application to the study of thin film buckling

    Energy Technology Data Exchange (ETDEWEB)

    Goudeau, P.; Villain, P.; Tamura, N.; Celestre, R.S.; Padmore, H.A.

    2002-11-06

    Thin films deposited by Physical Vapour Deposition techniques on substrates generally exhibit large residual stresses which may be responsible of spontaneous detachment of the film from its substrate and in the case of compressive stresses, thin film buckling. Although these effects are undesirable for future applications, one may take benefit of it for thin film mechanical properties investigation. Since the 80's, a lot of theoretical works have been done to develop mechanical models with the aim to get a better understanding of driven mechanisms giving rise to this phenomenon and thus to propose solutions to avoid such problems. Nevertheless, only a few experimental works have been done on this subject to support these theoretical results and nothing concerning local stress/strain measurement mainly because of the small dimension of the buckling (few tenth mm). This paper deals with the application of micro beam x-ray diffraction available on synchrotron radiation sources for stress/ strain mapping analysis of gold thin film buckling.

  14. Effects of the Substrate Temperature in AuN Thin Films by Means of X-Ray Diffraction

    Science.gov (United States)

    Devia, A.; Benavides, V.; Castillo, H. A.; Quintero, J.

    2006-12-01

    Gold is used in electronic industry like electric conductor for products such as computers, mobiles phones, etc; with the drawback that it is one of the most expensive metals in the market. Gold Nitride is a new material, having excellent physics properties like high hardness, high melting point, high electric conductivity, chemical inertia and good thermodynamic stabily among others. At the moment its study is more about electronics, optics, mechanical properties and growth of the films. AuN thin films were produced by the PAPVD (Plasma assisted Physics Vapor Deposition) method, using the pulsed arc technique in a mono-vaporizer system. These films were created with an Au target of 99% purity and deposited on stainless steel 304. It was observed that heating the substrate produces small stoichiometric changes in the film, which makes small changes in the diffraction patterns to appear, like widening in the Au orientation, since the composicional gradient is varying according to the substrate temperature. Au 4f and N1s narrow spectra were analyzed using XPS (X-Ray Photoelectron Spectroscopy), in order to observe stoichiometry in the films.

  15. Effects of the Substrate Temperature in AuN Thin Films by Means of X-Ray Diffraction

    International Nuclear Information System (INIS)

    Devia, A.; Benavides, V.; Castillo, H. A.; Quintero, J.

    2006-01-01

    Gold is used in electronic industry like electric conductor for products such as computers, mobiles phones, etc; with the drawback that it is one of the most expensive metals in the market. Gold Nitride is a new material, having excellent physics properties like high hardness, high melting point, high electric conductivity, chemical inertia and good thermodynamic stabily among others. At the moment its study is more about electronics, optics, mechanical properties and growth of the films. AuN thin films were produced by the PAPVD (Plasma assisted Physics Vapor Deposition) method, using the pulsed arc technique in a mono-vaporizer system. These films were created with an Au target of 99% purity and deposited on stainless steel 304. It was observed that heating the substrate produces small stoichiometric changes in the film, which makes small changes in the diffraction patterns to appear, like widening in the Au orientation, since the composicional gradient is varying according to the substrate temperature. Au 4f and N1s narrow spectra were analyzed using XPS (X-Ray Photoelectron Spectroscopy), in order to observe stoichiometry in the films

  16. Soft x-ray photoemission investigation of the oxidation of CuInSe/sub 2/ thin films

    International Nuclear Information System (INIS)

    Zurcher, P.; Nelson, A.J.; Johnson, P.; Lapeyre, G.J.; Noufi, R.

    1987-01-01

    CuInSe/sub 2/ films are used as absorber layers in heterojunction thin film solar cells. It has been demonstrated that, depending on the stoichiometry, oxygen annealing can make CuInSe/sub 2/ films more p-type or even convert n-type films into p-type while subsequent reduction with hydrazine will reverse such processes. Using synchrotron radiation soft x-ray photoemission spectroscopy, the authors found associated with the hydrazine reduced films an In1+ state that converts into In3+ under the influence of oxygen at elevated sample temperatures. The samples investigated were grown in a way that the top several thousand Angstroms are increasingly Cu-poor and In-rich. It is this region which is sampled by the surface sensitive technique of photoemission. The Cu-poor/In-rich top regions will most likely have a large number of intrinsic In on Cu-site defects leaving the In in a 1+ state. All the oxidation and reduction results and the associated changes in majority carrier concentrations and type conversions can be understood in terms of oxygem/In/sub Cu/-defect interactions

  17. Thin Film Structure of Tetraceno(2,3-B)thiophene Characterized By Grazing Incidence X-Ray Scattering And Near-Edge X-Ray Absorption Fine Structure Analysis

    International Nuclear Information System (INIS)

    Yuan, Q.; Mannsfeld, S.C.B.; Tang, M.L.; Toney, M.F.; Luening, J.; Bao, Z.A.

    2008-01-01

    Understanding the structure-property relationship for organic semiconductors is crucial in rational molecular design and organic thin film process control. Charge carrier transport in organic field-effect transistors predominantly occurs in a few semiconductor layers close to the interface in contact with the dielectric layer, and the transport properties depend sensitively on the precise molecular packing. Therefore, a better understanding of the impact of molecular packing and thin film morphology in the first few monolayers above the dielectric layer on charge transport is needed to improve the transistor performance. In this Article, we show that the detailed molecular packing in thin organic semiconductor films can be solved through a combination of grazing incidence X-ray diffraction (GIXD), near-edge X-ray absorption spectra fine structure (NEXAFS) spectroscopy, energy minimization packing calculations, and structure refinement of the diffraction data. We solve the thin film structure for 2 and 20 nm thick films of tetraceno(2,3-b)thiophene and detect only a single phase for these thicknesses. The GIXD yields accurate unit cell dimensions, while the precise molecular arrangement in the unit cell was found from the energy minimization and structure refinement; the NEXAFS yields a consistent molecular tilt. For the 20 nm film, the unit cell is triclinic with a = 5.96 A, b = 7.71 A, c = 15.16 A, alpha = 97.30 degrees, beta = 95.63 degrees, gamma = 90 degrees; there are two molecules per unit cell with herringbone packing (49-59 degree angle) and tilted about 7 degrees from the substrate normal. The thin film structure is significantly different from the bulk single-crystal structure, indicating the importance of characterizing thin film to correlate with thin film device performance. The results are compared to the corresponding data for the chemically similar and widely used pentacene. Possible effects of the observed thin film structure and morphology on

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different parts of the body absorb the x-rays in ...

  19. Thin film organic photodetectors for indirect X-ray detection demonstrating low dose rate sensitivity at low voltage operation

    Energy Technology Data Exchange (ETDEWEB)

    Starkenburg, Daken J. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611, USA; Johns, Paul M. [Nuclear Engineering Program, University of Florida, Gainesville, Florida 32611, USA; Detection Systems Group, Pacific Northwest National Laboratory, Richland, Washington 99354, USA; Baciak, James E. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611, USA; Nuclear Engineering Program, University of Florida, Gainesville, Florida 32611, USA; Nino, Juan C. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611, USA; Xue, Jiangeng [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611, USA

    2017-12-14

    Developments in the field of organic semiconductors have generated organic photodetectors with high quantum efficiency, wide spectral sensitivity, low power consumption, and unique form factors that are flexible and conformable to their substrate shape. In this work, organic photodetectors coupled with inorganic CsI(Tl) scintillators are used to showcase the low dose rate sensitivity that is enabled when high performance organic photodetectors and scintillator crystals are integrated. The detection capability of these organic-inorganic coupled systems to high energy radiation highlights their potential as an alternative to traditional photomultiplier tubes for nuclear spectroscopy applications. When exposed to Bremsstrahlung radiation produced from an X-ray generator, SubPc:C60, AlPcCl:C70, and P3HT:PC61BM thin film photodetectors with active layer thicknesses less than 100 nm show detection of incident radiation at low and no applied bias. Remarkably low dose rates, down to at least 0.28 µGy/s, were detectable with a characteristic linear relationship between exposure rate and photodetector current output. These devices also demonstrate sensitivities as high as 5.37 mC Gy-1 cm-2 when coupled to CsI(Tl). Additionally, as the tube voltage across the X-ray generator was varied, these organic-inorganic systems showed their ability to detect a range of continuous radiation spectra spanning several hundred keV.

  20. Thin film organic photodetectors for indirect X-ray detection demonstrating low dose rate sensitivity at low voltage operation

    Science.gov (United States)

    Starkenburg, Daken J.; Johns, Paul M.; Baciak, James E.; Nino, Juan C.; Xue, Jiangeng

    2017-12-01

    Developments in the field of organic semiconductors have generated organic photodetectors with high quantum efficiency, wide spectral sensitivity, low power consumption, and unique form factors that are flexible and conformable to their substrate shape. In this work, organic photodetectors coupled with inorganic CsI(Tl) scintillators are used to showcase the low dose rate sensitivity that is enabled when high performance organic photodetectors and scintillator crystals are integrated. The detection capability of these organic-inorganic coupled systems to high energy radiation highlights their potential as an alternative to traditional photomultiplier tubes for nuclear spectroscopy applications. When exposed to Bremsstrahlung radiation produced from an X-ray generator, SubPc:C60, AlPcCl:C70, and P3HT:PC61BM thin film photodetectors with active layer thicknesses less than 100 nm show detection of incident radiation at low and no applied bias. Remarkably low dose rates, down to at least 0.18 μGy/s, were detectable with a characteristic linear relationship between exposure rate and photodetector current output. These devices also demonstrate sensitivities as high as 5.37 mC Gy-1 cm-2 when coupled to CsI(Tl). Additionally, as the tube voltage across the X-ray generator was varied, these organic-inorganic systems showed their ability to detect a range of continuous radiation spectra spanning several hundred keV.

  1. Grazing incidence X-ray fluorescence analysis of buried interfaces in periodically structured crystalline silicon thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Eisenhauer, David; Preidel, Veit; Becker, Christiane [Young Investigator Group Nanostructured Silicon for Photovoltaic and Photonic Implementations (Nano-SIPPE), Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany); Pollakowski, Beatrix; Beckhoff, Burkhard [Physikalisch-Technische Bundesanstalt, Berlin (Germany); Baumann, Jonas; Kanngiesser, Birgit [Institut fuer Optik und Atomare Physik, Technische Universitaet Berlin (Germany); Amkreutz, Daniel; Rech, Bernd [Institut Silizium Photovoltaik, Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany); Back, Franziska; Rudigier-Voigt, Eveline [SCHOTT AG, Mainz (Germany)

    2015-03-01

    We present grazing incidence X-ray fluorescence (GIXRF) experiments on 3D periodically textured interfaces of liquid phase crystallized silicon thin-film solar cells on glass. The influence of functional layers (SiO{sub x} or SiO{sub x}/SiC{sub x}) - placed between glass substrate and silicon during crystallization - on the final carbon and oxygen contaminations inside the silicon was analyzed. Baring of the buried structured silicon surface prior to GIXRF measurement was achieved by removal of the original nano-imprinted glass substrate by wet-chemical etching. A broad angle of incidence distribution was determined for the X-ray radiation impinging on this textured surface. Optical simulations were performed in order to estimate the incident radiation intensity on the structured surface profile considering total reflection and attenuation effects. The results indicate a much lower contamination level for SiO{sub x} compared to the SiO{sub x}/SiC{sub x} interlayers, and about 25% increased contamination when comparing structured with planar silicon layers, both correlating with the corresponding solar cell performances. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Intra-operative X-ray diagnostics in the detection and localization of residual concretions in the kidney

    International Nuclear Information System (INIS)

    Soekeland, J.; Degenhardt, W.

    1979-01-01

    Problems of intra-operative X-ray diagnostics in the detection and localization of residual concretions in the kidney are discussed, together with the limitations of image-intensifier techniques, automatic exposure control, and the use of modified dental X-ray equipment. A technique using a film-screen combination and X-ray tube designed for mammography is discussed, together with its applications and possible future development. (Auth.)

  3. Characterization of quaternary metal oxide films by synchrotron x-ray fluorescence microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Perry, D.L.; Thompson, A.C.; Russo, R.E. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    A high demand for thin films in industrial technology has been responsible for the creation of new techniques for the fabrication of such films. One highly effective method for the syntheses of variable composition thin films is pulsed-laser deposition (PLD). The technique has a large number of characteristics which make it an attractive approach for making films. It offers rapid deposition rates, congruent material transfer, simple target requirements from which to make the films, in situ multilayer deposition, and no gas composition or pressure requirements. Additionally, the technique can also afford crystalline films and films with novel structures. Pulsed-laser deposition can be used to make films of semiconductors, insulators, high-temperature superconductors, diamond-like films, and piezoelectric materials. Quaternary metal oxides involving calcium, nickel, and potassium have been shown to be quite effective in the catalysis of coal gasification and methane coupling. One approach to incorporating all three of the metal oxides into one phase is the use of laser ablation to prepare films of the catalysts so that they may be used for coatings, smooth surfaces on which to conduct detailed studies of gas-solid interface reactions that are involved in catalytic processes, and other applications. The problem of dissimilar boiling points of the three metal oxides system is overcome, since the laser ablation process effects the volatilization of all three components from the laser target essentially simultaneously. There is strong interest in gaining an understanding of the chemical and morphological aspects of the films that are deposited. Phenomena such as lattice defects and chemical heterogeneity are of interest. The experimental data discussed here are restricted to the matrix homogeneity of the films themselves for films which were void of microparticles.

  4. X-ray diffraction stress analysis of ferroelectric thin films with ideal (h k l) textures considering the piezoelectric coupling effect

    International Nuclear Information System (INIS)

    Wu Huaping; Wu Linzhi; Li Jiquan; Chai Guozhong; Du Shanyi

    2010-01-01

    Ferroelectric thin films present large residual stress and strong texture during preparation, which affect the mechanical, dielectric and piezoelectric properties of the thin films. The determination of residual stresses in ferroelectric thin films with different textures is therefore very important. In this paper, an extended crystallite group model to evaluate the residual stresses of ferroelectric thin films using X-ray diffraction is proposed by considering the constitutive equation of orthogonally anisotropic ferroelectric medium. The effects of anisotropy and piezoelectric coupling on residual stresses of ferroelectric thin films are analyzed. X-ray stress factors for ideal (h k l)-textured ferroelectric thin films are obtained. An example of calculating the residual stresses of tetragonal perovskite ferroelectric thin films with (1 1 1) and (1 0 0) textures using the extended model is provided to validate the model.

  5. X-ray photoelectron spectroscopy study of the passive films formed on thermally sprayed and wrought Inconel 625

    Energy Technology Data Exchange (ETDEWEB)

    Bakare, M.S. [Materials, Mechanics and Structures Research Division, Faculty of Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Voisey, K.T., E-mail: Katy.voisey@nottingham.ac.uk [Materials, Mechanics and Structures Research Division, Faculty of Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Roe, M.J.; McCartney, D.G. [Materials, Mechanics and Structures Research Division, Faculty of Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom)

    2010-11-15

    There is a well known performance gap in corrosion resistance between thermally sprayed corrosion resistant coatings and the equivalent bulk materials. Interconnected porosity has an important and well known effect, however there are additional relevant microstructural effects. Previous work has shown that a compositional difference exists between the regions of resolidified and non-melted material that exist in the as-sprayed coatings. The resolidified regions are depleted in oxide forming elements due to formation of oxides during coating deposition. Formation of galvanic cells between these different regions is believed to decrease the corrosion resistance of the coating. In order to increase understanding of the details of this effect, this work uses X-ray photoelectron spectroscopy (XPS) to study the passive films formed on thermally sprayed coatings (HVOF) and bulk Inconel 625, a commercially available corrosion resistant Ni-Cr-Mo-Nb alloy. Passive films produced by potentiodynamic scanning to 400 mV in 0.5 M sulphuric acid were compared with air-formed films. The poorer corrosion performance of the thermally sprayed coatings was attributed to Ni(OH){sub 2}, which forms a loose, non-adherent and therefore non-protective film. The good corrosion resistance of wrought Inconel 625 is due to formation of Cr, Mo and Nb oxides.

  6. Inherent unsharpness of neutron radiographic image on X-ray films; Notranja neostrina nevtronografke slike na roentgenskih filmih

    Energy Technology Data Exchange (ETDEWEB)

    Ilic, R; Najzer, M [Institut Jozef Stefan, Ljubljana (Yugoslavia)

    1979-07-01

    The inherent unsharpness of the AGFA GEVART Structurix D-4 X-ray film was determined in terms of the unsharpness of the image of the knife edge test object for Gd converter 25 {mu}m In converters 50, 150 and 250 {mu}m and by Dy converters 7, 12, 25 and 60 {mu}m thick. The unsharpness of single coated film for Gd converter was found to be 56{+-}5 {mu}m. For In and Dy a value of 230 {+-} was obtained which was found to be independent on the converter type or thickness at least in the range of measuring error. The Inherent unsharpness of double coated film was 440 {+-} for In and 550{+-}50 {mu}m for Dy converter and was not dependent on the converter thickness. Comparing with single coated film the sensitivity was for a factor 1.6 higher for In and Dy converters. For Gd converter there was no gain in sensitivity and even the contrast was worse due to higher gamma ray background. (author)

  7. Elastic anisotropy of polycrystalline Au films: Modeling and respective contributions of X-ray diffraction, nanoindentation and Brillouin light scattering

    International Nuclear Information System (INIS)

    Faurie, D.; Djemia, P.; Le Bourhis, E.; Renault, P.-O.; Roussigne, Y.; Cherif, S.M.; Brenner, R.; Castelnau, O.; Patriarche, G.; Goudeau, Ph.

    2010-01-01

    Elastic properties of non-textured and {1 1 1}-fiber-textured gold thin films were investigated experimentally by several complementary techniques, namely in situ tensile testing under X-ray diffraction (XRD), nanoindentation and Brillouin light scattering (BLS). Specimens were probed along different directions to reveal the strong effects of elastic anisotropy at the (local) grain and (global) film scales. XRD allows the investigation of both local and global anisotropies, while BLS and nanoindentation are limited to global analyses. A micromechanical model, based on the self-consistent scheme, and accounting for the actual microstructure of the films, is applied to interpret experimental data. Although different types of elastic constants can be determined with the used experimental techniques (static/dynamic, local/global), a good agreement is obtained, showing that comparison of these techniques is feasible when carried out carefully. In particular, the use of a micromechanical model to estimate the effects of the local elastic anisotropy at the film scale is unavoidable. The presented results show that XRD, BLS and nanoindentation should capture anisotropic texture effects on elastic constants measurements for materials with a Zener anisotropy index larger than 2. Conversely, the actual texture of a given specimen should be taken into account for a proper analysis of elastic constants measurements using those three experimental techniques.

  8. X-ray photoelectron spectroscopy study and thermoelectric properties of Al-doped ZnO thin films

    International Nuclear Information System (INIS)

    Li Li; Fang Liang; Zhou Xianju; Liu Ziyi; Zhao Liang; Jiang Sha

    2009-01-01

    In this paper, high quality Al-doped ZnO (AZO) thin films were prepared by direct current (DC) reactive magnetron sputtering using a Zn target (99.99%) containing Al of 1.5 wt.%. The films obtained were characterized by X-ray photoelectron spectroscopy (XPS) and thermoelectric measurements. The XPS results reveal that Zn and Al exist only in oxidized state, while there are dominant crystal lattice and rare adsorbed oxygen for O in the annealed AZO thin films. The studies of thermoelectric property show a striking thermoelectric effect in the AZO thin films. On the one hand, the thermoelectromotive and magnetothermoelectromotive forces increase linearly with increasing temperature difference (ΔT). On the other hand, the thermoelectric power (TEP) decreases with the electrical resistance of the sample. But the TEP increases with the increase of temperature below 300 K, and it nearly does not change around room temperature. The experimental results also demonstrate that the annealing treatment increases TEP, while the external magnetic field degrades TEP.

  9. An in situ grazing incidence x-ray scattering study of block copolymer thin films during solvent vapor annealing

    Science.gov (United States)

    Gu, Xiaodan; Gunkel, Ilja; Hexemer, Alexander; Russell, Thomas

    2014-03-01

    Although solvent vapor annealing (SVA) has been widely applied to block copolymer (BCP) thin films to obtain well-ordered microdomains, the mechanism of enhancing lateral order is not well understood. Here, we used real time in situ grazing-incidence small-angle x-ray scattering (in situGISAXS) to study the self-assembly of PS-b-P2VP BCP BCPs with different molecular weights thin films in THF vapor, a near neutral solvent for both blocks. Both swelling and deswelling behavior of BCP thin films were examined. The extent of swellingand the solvent removal rate not only affect the domain spacing of BCPs but also dictate the extent of lateral ordering of the BCP microdomains. Larger grains were observed at higher values of the swelling ratio (close to disordering). To preserve the maximal lateral ordering of the microdomains in the swollen state, the fastest solvent removal rate is required to freeze in the ordered microdomain structure of the swollen BCP film. We thanks support from U.S. Department of Energy BES under contract BES-DE-FG02-96ER45612 and ALS doctoral fellowship.

  10. X-Ray diffraction analysis of thermally evaporated copper tin selenide thin films at different annealing temperature

    International Nuclear Information System (INIS)

    Mohd Amirul Syafiq Mohd Yunos; Zainal Abidin Talib; Wan Mahmood Mat Yunus; Josephine Liew Ying Chyi; Wilfred Sylvester Paulus

    2010-01-01

    Semiconductor thin films Copper Tin Selenide, Cu 2 SnSe 3 , a potential compound for semiconductor radiation detector or solar cell applications were prepared by thermal evaporation method onto well-cleaned glass substrates. The as-deposited films were annealed in flowing purified nitrogen, N 2 , for 2 hours in the temperature range from 100 to 500 degree Celsius. The structure of as-deposited and annealed films has been studied by X-ray diffraction technique. The semi-quantitative analysis indicated from the Reitveld refinement show that the samples composed of Cu 2 SnSe 3 and SnSe. These studies revealed that the films were structured in mixed phase between cubic space group F-43 m (no. 216) and orthorhombic space group P n m a (no. 62). The crystallite size and lattice strain were determined from Scherrer calculation method. The results show that increasing in annealing temperature resulted in direct increase in crystallite size and decrease in lattice strain. (author)

  11. X-ray reflectivity study of bias graded diamond like carbon film ...

    Indian Academy of Sciences (India)

    destructive technique for determining layer thickness, sur- face and interfacial roughness and internal structure of films. The XRR technique is alike the optical reflectivity technique and is performed at a glancing angle. ..... critical incident energy window the film attains minimum roughness. Thereafter, for higher energy the ...

  12. Electronic structure of Al- and Ga-doped ZnO films studied by hard X-ray photoelectron spectroscopy

    Directory of Open Access Journals (Sweden)

    M. Gabás

    2014-01-01

    Full Text Available Al- and Ga-doped sputtered ZnO films (AZO, GZO are semiconducting and metallic, respectively, despite the same electronic valence structure of the dopants. Using hard X-ray photoelectron spectroscopy we observe that both dopants induce a band in the electronic structure near the Fermi level, accompanied by a narrowing of the Zn 3d/O 2p gap in the valence band and, in the case of GZO, a substantial shift in the Zn 3d. Ga occupies substitutional sites, whereas Al dopants are in both substitutional and interstitial sites. The latter could induce O and Zn defects, which act as acceptors explaining the semiconducting character of AZO and the lack of variation in the optical gap. By contrast, mainly substitutional doping is consistent with the metallic-like behavior of GZO.

  13. Soft X-ray angle-resolved photoemission spectroscopy of heavily boron-doped superconducting diamond films

    Directory of Open Access Journals (Sweden)

    T. Yokoya, T. Nakamura, T. Matushita, T. Muro, H. Okazaki, M. Arita, K. Shimada, H. Namatame, M. Taniguchi, Y. Takano, M. Nagao, T. Takenouchi, H. Kawarada and T. Oguchi

    2006-01-01

    Full Text Available We have performed soft X-ray angle-resolved photoemission spectroscopy (SXARPES of microwave plasma-assisted chemical vapor deposition diamond films with different B concentrations in order to study the origin of the metallic behavior of superconducting diamond. SXARPES results clearly show valence band dispersions with a bandwidth of ~23 eV and with a top of the valence band at gamma point in the Brillouin zone, which are consistent with the calculated valence band dispersions of pure diamond. Boron concentration-dependent band dispersions near the Fermi level (EF exhibit a systematic shift of EF, indicating depopulation of electrons due to hole doping. These SXARPES results indicate that diamond bands retain for heavy boron doping and holes in the diamond band are responsible for the metallic states leading to superconductivity at low temperature. A high-resolution photoemission spectroscopy spectrum near EF of a heavily boron-doped diamond superconductor is also presented.

  14. Reduction of the scattered radiation during X-ray examination with screen-film systems

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, V N; Stavitsky, R V [Moscow Research Inst. for Roentgenology and Radiology, Moscow (Russian Federation); Oshomkov, Yu V [Mosroentgen, Moscow Region (Russian Federation)

    1993-01-01

    In diagnostic radiography, during X-ray examination, photons scattered in the patient's body are detected by the intensifying screen and decrease the image contrast. A conventional way to avoid this image degradation is to attenuate the scattered radiation by an antiscatter grid placed between the patient's body and the screen. A grid selectivity effect originates from the greater attenuation of scattered as opposed to primary radiation. Previous authors calculated the primary and scattered radiation transmission factor of photons with initial energy 30-120 keV for a number of typical grids. The primary radiation transmission factor varied from 0.34 to 0.67 and the secondary radiation factor was equal from 0.03 to 0.13. This effect results in a contrast improvement from 2 to 6, but the patient exposure increases up to a factor of 10. In this work we studied the possibility of improving the image contrast by attenuating the scattered radiation by a secondary filter placed between the patient's body and the screen and made of an appropriate material. A selectivity effect due to the secondary filter arises from two circumstances. First, tilting incidence of the scattered radiation results in the path inside the filter being greater than the primary one. Second, the average energy of the scattered radiation is less than the primary and, hence, the attenuation coefficient is greater. (author).

  15. Structural sensitivity of x-ray Bragg projection ptychography to domain patterns in epitaxial thin films

    International Nuclear Information System (INIS)

    Hruszkewycz, S. O.; Zhang, Q.; Holt, M. V.; Highland, M. J.

    2016-01-01

    Bragg projection ptychography (BPP) is a coherent diffraction imaging technique capable of mapping the spatial distribution of the Bragg structure factor in nanostructured thin films. Here, we show that, because these images are projections, the structural sensitivity of the resulting images depends on the film thickness and the aspect ratio and orientation of the features of interest and that image interpretation depends on these factors. Lastly, we model changes in contrast in the BPP reconstructions of simulated PbTiO_3 ferroelectric thin films with meandering 180° stripe domains as a function of film thickness, discuss their origin, and comment on the implication of these factors on the design of BPP experiments of general nanostructured films.

  16. Skull x-ray

    Science.gov (United States)

    X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  17. Neck x-ray

    Science.gov (United States)

    X-ray - neck; Cervical spine x-ray; Lateral neck x-ray ... There is low radiation exposure. X-rays are monitored so that the lowest amount of radiation is used to produce the image. Pregnant women and ...

  18. Correlation between the dielectric constant and X-ray diffraction pattern of Si-O-C thin films with hydrogen bonds

    International Nuclear Information System (INIS)

    Oh, Teresa; Oh, Kyoung Suk; Lee, Kwang-Man; Choi, Chi Kyu

    2004-01-01

    The amorphous structure of organic-inorganic hybrid type Si-O-C thin films was studied using the first principles molecular-dynamics method with density functional techniques. The correlation between the dielectric constant and the degree of amorphous structure in organic-inorganic hybrid type Si-O-C thin films was studied. Si-O-C thin films were deposited by high-density plasma chemical vapor deposition using bis-trimethylsilylmethane and oxygen precursors. As-deposited films and films annealed at 500 deg. C were analyzed by X-ray diffraction (XRD). For quantitative analysis, the X-ray diffraction patterns of the samples were transformed to the radial distribution function (RDF) using Fourier analysis. Hybrid type Si-O-C thin films can be divided into three types using their amorphous structure and the dielectric constant: those with organic, hybrid, and inorganic properties

  19. Calibration of GafChromic XR-RV3 radiochromic film for skin dose measurement using standardized x-ray spectra and a commercial flatbed scanner

    International Nuclear Information System (INIS)

    McCabe, Bradley P.; Speidel, Michael A.; Pike, Tina L.; Van Lysel, Michael S.

    2011-01-01

    Purpose: In this study, newly formulated XR-RV3 GafChromic film was calibrated with National Institute of Standards and Technology (NIST) traceability for measurement of patient skin dose during fluoroscopically guided interventional procedures. Methods: The film was calibrated free-in-air to air kerma levels between 15 and 1100 cGy using four moderately filtered x-ray beam qualities (60, 80, 100, and 120 kVp). The calibration films were scanned with a commercial flatbed document scanner. Film reflective density-to-air kerma calibration curves were constructed for each beam quality, with both the orange and white sides facing the x-ray source. A method to correct for nonuniformity in scanner response (up to 25% depending on position) was developed to enable dose measurement with large films. The response of XR-RV3 film under patient backscattering conditions was examined using on-phantom film exposures and Monte Carlo simulations. Results: The response of XR-RV3 film to a given air kerma depended on kVp and film orientation. For a 200 cGy air kerma exposure with the orange side of the film facing the source, the film response increased by 20% from 60 to 120 kVp. At 500 cGy, the increase was 12%. When 500 cGy exposures were performed with the white side facing the x-ray source, the film response increased by 4.0% (60 kVp) to 9.9% (120 kVp) compared to the orange-facing orientation. On-phantom film measurements and Monte Carlo simulations show that using a NIST-traceable free-in-air calibration curve to determine air kerma in the presence of backscatter results in an error from 2% up to 8% depending on beam quality. The combined uncertainty in the air kerma measurement from the calibration curves and scanner nonuniformity correction was ±7.1% (95% C.I.). The film showed notable stability. Calibrations of film and scanner separated by 1 yr differed by 1.0%. Conclusions: XR-RV3 radiochromic film response to a given air kerma shows dependence on beam quality and film

  20. X-ray film reject rate analysis at eight selected government hospitals ...

    African Journals Online (AJOL)

    admin

    the quality and efficiency of radiology services is imperative. ... principle). One way of achieving this is through a quality assurance program, which includes procedures that help ..... audit of film rejects and repeats rates in a department.

  1. Analysis of tumor-like shadows on abdominal plain x-ray film

    International Nuclear Information System (INIS)

    Hayashi, Hidehiro; Hiraki, Yoshio; Hashimoto, Keizi

    1986-01-01

    We found tumor-like shadows in the upper abdomen in 93 cases out of 400 abdominal plain films, although none of these 93 cases actually had a tumor. We analyzed these tumor-like shadows by computed tomography. For each of the 400 cases we measured the width of flank stripe on the abdominal plain film. Most of the tumor-like shadows in the left upper abdomen were gastric fundus, but it was significant for evaluating plain abdominal film that other organs such as a part of the left lobe of the liver, the upper pole of the left kidney, and a part of the spleen formed tumor-like shadows. The most important factors forming tumor-like shadows on plain abdominal film are the fat volume of the abdominal cauity as well as the fraciform ligament and alterations in the shape and volume of organs such as occur in liver cirrhosis. (author)

  2. Application of high-resolution film for lithography to synchrotron X-ray topography

    International Nuclear Information System (INIS)

    Mizuno, Kaoru; Ito, Kazuyoshi; Iwami, Masayuki; Hashimoto, Eiji; Kino, Takao.

    1994-01-01

    A high-resolution film for lithography is applied to a detector for synchrotron radiation topography, instead of a nuclear plate. The film shows much better resolution than that of the plate although exposure time an about 500 times longer is required. The size distribution of interstitial loops grown as vacancy sources in a nearly perfect aluminum crystal after a temperature rise is examined from the while beam topograph. (author)

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... a large photographic negative). Today, most images are digital files that are stored electronically. These stored images ... and places the x-ray film holder or digital recording plate under the table in the area ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different parts of the body absorb the x-rays in varying degrees. Dense ...

  5. X-ray diffraction from thin films : Size/strain analysis and whole pattern fitting

    Energy Technology Data Exchange (ETDEWEB)

    Scardi, P [Trento Univ. (Italy). Dept. of Materials Engineering

    1996-09-01

    Line Profile Analysis (LPA) and whole pattern fitting may be used with success for the characterization of thin films from XRD data collected with the traditional Bragg-Brentano geometry. The size/strain analysis was conducted by an integrated procedure of profile modelling-assisted Fourier analysis, in order to measure the content of lattice imperfections and crystalline domain size along the growth direction in heteroepitaxial thin films. The microstructure of these films is typical of several PVD processes for the production of highly textured and low-defect thin crystalline layers. The same analysis could be conducted on random thin films as well, and in this case it is possible to determine an average crystallite size and shape. As will be shown in the paper, structural and microstructural parameters obtained by these methods may be correlated with thin film properties of technological interest. The whole pattern analysis may be used to obtain the information contained in a wide region of the diffraction pattern. This approach, currently used for the quantitative analysis of phase mixtures in traditional powder samples, was modified to account both for the size/strain effects, according to a simplified LPA, and for the structure of thin films and multi-layer systems. In this way, a detailed analysis based on a structural model for the present phases can be performed considering the real geometry of these samples. In particular, the quantitative phase analysis could be conducted in terms of layer thickness instead of volume or weight fractions.

  6. X-ray diffraction from thin films : Size/strain analysis and whole pattern fitting

    International Nuclear Information System (INIS)

    Scardi, P.

    1996-01-01

    Line Profile Analysis (LPA) and whole pattern fitting may be used with success for the characterization of thin films from XRD data collected with the traditional Bragg-Brentano geometry. The size/strain analysis was conducted by an integrated procedure of profile modelling-assisted Fourier analysis, in order to measure the content of lattice imperfections and crystalline domain size along the growth direction in heteroepitaxial thin films. The microstructure of these films is typical of several PVD processes for the production of highly textured and low-defect thin crystalline layers. The same analysis could be conducted on random thin films as well, and in this case it is possible to determine an average crystallite size and shape. As will be shown in the paper, structural and microstructural parameters obtained by these methods may be correlated with thin film properties of technological interest. The whole pattern analysis may be used to obtain the information contained in a wide region of the diffraction pattern. This approach, currently used for the quantitative analysis of phase mixtures in traditional powder samples, was modified to account both for the size/strain effects, according to a simplified LPA, and for the structure of thin films and multi-layer systems. In this way, a detailed analysis based on a structural model for the present phases can be performed considering the real geometry of these samples. In particular, the quantitative phase analysis could be conducted in terms of layer thickness instead of volume or weight fractions

  7. Metal induced crystallization of amorphous silicon thin films studied by x-ray absorption fine structure spectroscopy

    International Nuclear Information System (INIS)

    Naidu, K Lakshun; Mohiddon, Md Ahamad; Dalba, G; Krishna, M Ghanashyam; Rocca, F

    2013-01-01

    The role of thin metallic layer (Chromium or Nickel) in the crystallization of a-Si film has been studied using X-ray absorption fine structure spectroscopy (XAFS). The films were grown at different substrate temperatures in two different geometrical structures : (a) a 200 nm metal layer (Cr or Ni) was deposited on fused silica (FS) followed by 400 nm of a-Si and (b) the 400 nm a-Si layer was deposited on FS followed by 200 nm of metal layer. XAFS measurements at Cr K-edge and Ni K-edge were done at BM08 – GILDA beamline of the European Synchrotron Research Facility (ESRF, Grenoble, F) in fluorescence mode. To understand the evolution of the local structure of Cr/Ni diffusing from bottom to top and from top to bottom, total reflection and higher incidence angles were employed. The relative content of metal, metal oxide and metal silicides compounds on the upper surface and/or in the bulk of different films has been evaluated as a function of thermal treatment.

  8. Study of the electrodeposition of rhenium thin films by electrochemical quartz microbalance and X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Schrebler, R.; Cury, P.; Suarez, C.; Munoz, E.; Vera, F.; Cordova, R.; Gomez, H.; Ramos-Barrado, J.R.; Leinen, D.; Dalchiele, E.A.

    2005-01-01

    Rhenium thin films were prepared by electrodeposition from an aqueous solution containing 0.1 M Na 2 SO 4 +H 2 SO 4 , pH 2 in presence of y mM HReO 4 . As substrates polycrystalline gold (y=0.75 mM HReO 4 ) and monocrystalline n-Si(100) (y=40 mM HReO 4 ) were used. The electrochemical growth of rhenium was studied by cyclic voltammetry and electrochemical quartz microbalance on gold electrodes. The results found in the potential region before the hydrogen evolution reaction (her) showed that ReO 3 , ReO 2 and Re 2 O 3 with different hydration grades can be formed. In the potential region where the her is occurring, either on gold or n-Si(100) the electrodeposition of metallic rhenium takes place. On both substrates, rhenium films were formed by electrolysis at constant potential and X-ray photoelectron spectroscopy technique was used to characterise these deposits. It was concluded that the electrodeposited films were of metallic rhenium and only the uppermost atomic layer contained rhenium oxide species

  9. In situ surface X-ray diffraction study of ultrathin epitaxial Co films on Au(111) in alkaline solution

    International Nuclear Information System (INIS)

    Reikowski, Finn; Maroun, Fouad; Di, Nan; Allongue, Philippe; Ruge, Martin; Stettner, Jochim; Magnussen, Olaf M.

    2016-01-01

    The oxidation behavior of ultrathin electrodeposited Co films on Au(111) in alkaline electrolyte was studied using in situ surface X-ray scattering techniques employing synchrotron radiation and complementary optical reflectivity and electrochemical measurements. The films are formed at pH 4 and consist of (001)-oriented hcp Co crystallites that are several nm high, a few ten nm in diameter, and remain largely unchanged after electrolyte exchange to pH 12 solution. In the pre-oxidation peak only minor changes were observed in the diffraction studies, excluding the formation of Co(OH)_2 layers. In the potential regime of Co hydroxide formation a rapid reduction of the amount of Co is observed, while the characteristic height of the islands decreases only slightly. On longer times scales, growth of 3D crystals of Co(OH)_2 occurs as well as irreversible Co dissolution into the electrolyte is found. On the basis of the structural observations oxidation of the Co film is proposed to proceed via fast formation of an ultrathin passivating layer, followed by nucleation and growth of 3D hydroxide crystals at the grain boundaries in the Co deposit.

  10. Hydrogen Absorption in Metal Thin Films and Heterostructures Investigated in Situ with Neutron and X-ray Scattering

    Directory of Open Access Journals (Sweden)

    Sara J. Callori

    2016-05-01

    Full Text Available Due to hydrogen possessing a relatively large neutron scattering length, hydrogen absorption and desorption behaviors in metal thin films can straightforwardly be investigated by neutron reflectometry. However, to further elucidate the chemical structure of the hydrogen absorbing materials, complementary techniques such as high resolution X-ray reflectometry and diffraction remain important too. Examples of work on such systems include Nb- and Pd-based multilayers, where Nb and Pd both have strong affinity to hydrogen. W/Nb and Fe/Nb multilayers were measured in situ with unpolarized and polarized neutron reflectometry under hydrogen gas charging conditions. The gas-pressure/hydrogen-concentration dependence, the hydrogen-induced macroscopic film swelling as well as the increase in crystal lattice plane distances of the films were determined. Ferromagnetic-Co/Pd multilayers were studied with polarized neutron reflectometry and in situ ferromagnetic resonance measurements to understand the effect of hydrogen absorption on the magnetic properties of the system. This electronic effect enables a novel approach for hydrogen sensing using a magnetic readout scheme.

  11. Microstructural characterization of dental zinc phosphate cements using combined small angle neutron scattering and microfocus X-ray computed tomography

    Czech Academy of Sciences Publication Activity Database

    Viani, Alberto; Sotiriadis, Konstantinos; Kumpová, Ivana; Mancini, L.; Appavou, M.-S.

    2017-01-01

    Roč. 33, č. 4 (2017), s. 402-417 ISSN 0109-5641 R&D Projects: GA MŠk(CZ) LO1219 Keywords : zinc phosphate cements * small angle neutron scattering * X-ray micro-computed tomography * X-ray powder diffraction * zinc oxide * acid-base cements Subject RIV: JJ - Other Materials OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics Impact factor: 4.070, year: 2016 https://www.sciencedirect.com/science/article/pii/S0109564116305127

  12. Technique charts for Kodak EC-L film screen system for portal localization in a 6MV X-ray beam.

    Science.gov (United States)

    Sandilos, P; Antypas, C; Paraskevopoulou, C; Kouvaris, J; Vlachos, L

    2006-01-01

    Port films are used in radiotherapy for visual evaluation of the radiation fields and subsequent quantitative analysis. Common port films suffer from poor image quality compared to the simulator-diagnostic films and is desirable to determine the appropriate exposure required for the best image contrast. The aim of this work is to generate technique charts for the Kodak EC-L film screen system for use in a 6MV x-ray beam. Three homogeneous water phantoms were used to simulate head-neck, thorax and abdomen dimensions of adult human, correspondingly. The film screen system was calibrated in a 6MV x-ray beam and under various irradiation conditions. The film screen system behavior was studied as a function of phantom thickness, field size and air gap between the phantom and the film screen system. In each case the optimum film exposure which produces the maximum image contrast was determined. The generated technique charts for the EC-L film screen system and for a 6 MV x-ray beam are used in our radiotherapy department for daily quality assurance of the radiotherapy procedure.

  13. X-ray absorption and emission study of amorphous and nanocrystalline GaN films containing buried N2

    International Nuclear Information System (INIS)

    Ruck, B.J.; Koo, A.; Budde, F.; Granville, S.; Trodahl, H.J.

    2004-01-01

    Full text: It has been predicted that amorphous gallium nitride (a-GaN) may possess a well-defined wide band gap, and is thus a potential substitute for the more expensive crystalline form used in short wavelength optoelectronic devices. Experimental investigations of disordered GaN have lent support to this prediction, but the picture is complicated because the properties of the amorphous state are not unique, and instead depend on the exact nature of the disordered structure. We have pioneered a novel ion-assisted growth technique that produces GaN films with a microstructure that ranges from nanocrystalline, with crystallite size of order 3 nm, to fully amorphous, depending on the exact growth conditions. This presentation will give an overview of our research into the properties of disordered GaN, including characterization of the physical structure of the films and their electronic energy levels, and also their photoconductive response. In particular I will focus on synchrotron radiation studies of samples with a range of different microstructures. X-ray absorption spectroscopy (XAS) and x-ray emission spectroscopy (XES) provide particularly powerful tools for examining a sample's empty and filled electronic energy levels, respectively. The details of the absorption and emission processes make it possible to obtain atom-specific information and to investigate the symmetry of the electronic levels. An example of the information obtained is shown. The thin solid curve shows XAS data, which is a measure of the nitrogen /7-projected density of unfilled electronic states in this nanocrystalline GaN sample. The thick solid curve shows XES data from the same sample, which provides complementary information about the occupied valence band states. Although the spectral features are broader in fully amorphous films than in nanocrystalline samples, a well-defined band gap exists in both cases with magnitude similar to that of crystalline GaN. There are additional feature

  14. Magnetic x-ray linear dichroism of ultrathin Fe-Ni alloy films

    Energy Technology Data Exchange (ETDEWEB)

    Schumann, F.O.; Willis, R.F. [Pennsylvania State Univ., University Park, PA (United States); Goodman, K.W. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    The authors have studied the magnetic structure of ultrathin Fe-Ni alloy films as a function of Fe concentration by measuring the linear dichroism of the 3p-core levels in angle-resolved photoemission spectroscopy. The alloy films, grown by molecular-beam epitaxy on Cu(001) surfaces, were fcc and approximately four monolayers thick. The intensity of the Fe dichroism varied with Fe concentration, with larger dichroisms at lower Fe concentrations. The implication of these results to an ultrathin film analogue of the bulk Invar effect in Fe-Ni alloys will be discussed. These measurements were performed at the Spectromicroscopy Facility (Beamline 7.0.1) of the Advanced Light Source.

  15. Performance of a gaseous detector based energy dispersive X-ray fluorescence imaging system: Analysis of human teeth treated with dental amalgam

    International Nuclear Information System (INIS)

    Silva, A.L.M.; Figueroa, R.; Jaramillo, A.; Carvalho, M.L.; Veloso, J.F.C.A.

    2013-01-01

    Energy dispersive X-ray fluorescence (EDXRF) imaging systems are of great interest in many applications of different areas, once they allow us to get images of the spatial elemental distribution in the samples. The detector system used in this study is based on a micro patterned gas detector, named Micro-Hole and Strip Plate. The full field of view system, with an active area of 28 × 28 mm 2 presents some important features for EDXRF imaging applications, such as a position resolution below 125 μm, an intrinsic energy resolution of about 14% full width at half maximum for 5.9 keV X-rays, and a counting rate capability of 0.5 MHz. In this work, analysis of human teeth treated by dental amalgam was performed by using the EDXRF imaging system mentioned above. The goal of the analysis is to evaluate the system capabilities in the biomedical field by measuring the drift of the major constituents of a dental amalgam, Zn and Hg, throughout the tooth structures. The elemental distribution pattern of these elements obtained during the analysis suggests diffusion of these elements from the amalgam to teeth tissues. - Highlights: • Demonstration of an EDXRF imaging system based on a 2D-MHSP detector for biological analysis • Evaluation of the drift of the dental amalgam constituents, throughout the teeth • Observation of Hg diffusion, due to hydroxyapatite crystal defects that compose the teeth tissues

  16. Performance of a gaseous detector based energy dispersive X-ray fluorescence imaging system: Analysis of human teeth treated with dental amalgam

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.L.M. [I3N, Physics Dept, University of Aveiro, 3810-193 Aveiro (Portugal); Figueroa, R.; Jaramillo, A. [Physics Department, Universidad de La Frontera, Temuco (Chile); Carvalho, M.L. [Atomic Physics Centre, University of Lisbon, 1649-03 Lisboa (Portugal); Veloso, J.F.C.A., E-mail: joao.veloso@ua.pt [I3N, Physics Dept, University of Aveiro, 3810-193 Aveiro (Portugal)

    2013-08-01

    Energy dispersive X-ray fluorescence (EDXRF) imaging systems are of great interest in many applications of different areas, once they allow us to get images of the spatial elemental distribution in the samples. The detector system used in this study is based on a micro patterned gas detector, named Micro-Hole and Strip Plate. The full field of view system, with an active area of 28 × 28 mm{sup 2} presents some important features for EDXRF imaging applications, such as a position resolution below 125 μm, an intrinsic energy resolution of about 14% full width at half maximum for 5.9 keV X-rays, and a counting rate capability of 0.5 MHz. In this work, analysis of human teeth treated by dental amalgam was performed by using the EDXRF imaging system mentioned above. The goal of the analysis is to evaluate the system capabilities in the biomedical field by measuring the drift of the major constituents of a dental amalgam, Zn and Hg, throughout the tooth structures. The elemental distribution pattern of these elements obtained during the analysis suggests diffusion of these elements from the amalgam to teeth tissues. - Highlights: • Demonstration of an EDXRF imaging system based on a 2D-MHSP detector for biological analysis • Evaluation of the drift of the dental amalgam constituents, throughout the teeth • Observation of Hg diffusion, due to hydroxyapatite crystal defects that compose the teeth tissues.

  17. Electronic properties and bonding in Zr Hx thin films investigated by valence-band x-ray photoelectron spectroscopy

    Science.gov (United States)

    Magnuson, Martin; Schmidt, Susann; Hultman, Lars; Högberg, Hans

    2017-11-01

    The electronic structure and chemical bonding in reactively magnetron sputtered Zr Hx (x =0.15 , 0.30, 1.16) thin films with oxygen content as low as 0.2 at.% are investigated by 4d valence band, shallow 4p core-level, and 3d core-level x-ray photoelectron spectroscopy. With increasing hydrogen content, we observe significant reduction of the 4d valence states close to the Fermi level as a result of redistribution of intensity toward the H 1s-Zr 4d hybridization region at ˜6 eV below the Fermi level. For low hydrogen content (x =0.15 , 0.30), the films consist of a superposition of hexagonal closest-packed metal (α phase) and understoichiometric δ -Zr Hx (Ca F2 -type structure) phases, while for x =1.16 , the films form single-phase Zr Hx that largely resembles that of stoichiometric δ -Zr H2 phase. We show that the cubic δ -Zr Hx phase is metastable as thin film up to x =1.16 , while for higher H contents the structure is predicted to be tetragonally distorted. For the investigated Zr H1.16 film, we find chemical shifts of 0.68 and 0.51 eV toward higher binding energies for the Zr 4 p3 /2 and 3 d5 /2 peak positions, respectively. Compared to the Zr metal binding energies of 27.26 and 178.87 eV, this signifies a charge transfer from Zr to H atoms. The change in the electronic structure, spectral line shapes, and chemical shifts as a function of hydrogen content is discussed in relation to the charge transfer from Zr to H that affects the conductivity by charge redistribution in the valence band.

  18. X-ray diffraction analysis of thermally-induced stress relaxation in ZnO films deposited by magnetron sputtering on (100) Si substrates

    Energy Technology Data Exchange (ETDEWEB)

    Conchon, F., E-mail: florineconchon@gmail.co [Laboratoire de Physique des Materiaux (PHYMAT) UMR 6630, Universite de Poitiers, 86962 Futuroscope-Chasseneuil (France); Renault, P.O.; Goudeau, P.; Le Bourhis, E. [Laboratoire de Physique des Materiaux (PHYMAT) UMR 6630, Universite de Poitiers, 86962 Futuroscope-Chasseneuil (France); Sondergard, E.; Barthel, E.; Grachev, S. [Laboratoire de Surface du Verre et Interfaces (SVI), UMR 125, 93303 Aubervilliers (France); Gouardes, E.; Rondeau, V.; Gy, R. [Laboratoire de Recherche de Saint-Gobain (SGR), 93303 Aubervilliers (France); Lazzari, R.; Jupille, J. [Institut des Nanosciences de Paris (INSP), UMR 7588, 75015 Paris (France); Brun, N. [Laboratoire de Physique des Solides (LPS), UMR 8502, 91405 Orsay (France)

    2010-07-01

    Residual stresses in sputtered ZnO films on Si are determined and discussed. By means of X-ray diffraction, we show that as-deposited ZnO films are highly compressively stressed. Moreover, a transition of stress is observed as a function of the post-deposition annealing temperature. After an 800 {sup o}C annealing, ZnO films are tensily stressed while ZnO films encapsulated by Si{sub 3}N{sub 4} are stress-free. With the aid of in-situ X-ray diffraction under ambient and argon atmosphere, we argue that this thermally activated stress relaxation may be attributed to a variation of the stoichiometry of the ZnO films.

  19. X-ray detected magnetic resonance of YIG thin films in the nonlinear regime of spin waves

    Energy Technology Data Exchange (ETDEWEB)

    Goulon, J., E-mail: goulon@esrf.f [European Synchrotron Radiation Facility (ESRF), B.P. 220, F-38043 Grenoble Cedex (France); Rogalev, A.; Wilhelm, F.; Goujon, G. [European Synchrotron Radiation Facility (ESRF), B.P. 220, F-38043 Grenoble Cedex (France); Brouder, Ch. [Institut de Mineralogie et de Physique des Milieux Condenses, UMR-CNRS 7590, Universite Paris VI-VII, 4 place Jussieu, F-75252 Paris Cedex 05 (France); Yaresko, A. [Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart (Germany); Ben Youssef, J.; Indenbom, M.V. [Laboratoire de Magnetisme de Bretagne, CNRS FRE 2697, UFR Sciences et Techniques, F-29328 Brest Cedex (France)

    2010-08-15

    We discuss the information content of element/edge resolved X-ray detected magnetic resonance (XDMR) experiments carried out on yttrium iron garnet (YIG) thin films. Starting with a phenomenological approach, it is shown that the photoionisation of deep atomic core levels by circularly polarized X-rays can be used to probe the precession dynamics of spin or orbital magnetization components in empty final states of proper symmetry. Crude estimates of the opening angle of the uniform precession mode were tentatively deduced from the ratio of the XDMR and XMCD absorption cross-sections either at the iron or yttrium absorbing sites. The implications of the most recent experimental results collected at the ESRF are analyzed, keeping in mind that: (i) the Fe K-edge XDMR signal is largely dominated by the precession of orbital magnetization components at the tetrahedral iron sites; (ii) the Y L-edges XDMR signal essentially describes the precession of induced spin magnetization involving the 4d states of yttrium. In the magnetostatic regime, we produce clear experimental evidence of collective excitations of orbital magnetization waves, especially under high pumping power. Several coupling mechanisms could explain our observations, starting with pseudo-dipolar interactions in ferromagnetic systems. In ferrimagnetic systems in which orbital degeneracy and orbital ordering make the excitation of orbitons possible, one may envisage additional modes of excitation or relaxation of orbital magnetization waves. This interpretation looks fully consistent with the results of band structure calculations carried out recently on YIG with fully relativistic LMTO-LSDA methods.

  20. The epitaxial growth and interfacial strain study of VO{sub 2}/MgF{sub 2} (001) films by synchrotron based grazing incidence X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Fan, L.L. [Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng 224051 (China); National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Chen, S. [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Liu, Q.H. [Science and Technology on Electro-optical Information Security Control Laboratory, Tianjin 300300 (China); Liao, G.M.; Chen, Y.L.; Ren, H. [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Zou, C.W., E-mail: czou@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China)

    2016-09-05

    High quality VO{sub 2} films with different thickness were epitaxially grown on MgF{sub 2} (001) substrates by oxide molecular beam epitaxy method. The evolution of interfacial strain was investigated by synchrotron based grazing incidence X-ray diffraction. By adjusting the incidence angles, the penetration depth of X-ray in VO{sub 2} film could be controlled and the thickness-depend lattice distortion in the epitaxial VO{sub 2} film was investigated. Due to the lattice mismatching, the pronounced tensile strain was observed in ultra-thin VO{sub 2} film. As the film thickness increasing, the interfacial strain relaxed gradually and became fully relaxed for thick VO{sub 2} films. Combined with the electric transport measurement, it was revealed that the phase transition temperature of ultra-thin VO{sub 2} film decreased greatly. The effect of interfacial strain induced phase transition modulation and the intrinsic mechanism was systematically discussed. - Highlights: • We prepared high quality VO{sub 2} epitaxial films on MgF{sub 2} (001) substrates by oxide molecular beam epitaxy method. • Synchrotron radiation grazing incidence X-ray diffraction was employed to detect evolution of strain along depth profile. • Based on a classic band structure model, the mechanism of strain controlled phase transition of VO{sub 2} was discussed.

  1. X-ray scattering of calcite thin films deposited by atomic layer deposition: Studies in air and in calcite saturated water solution

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peng [Lujan Neutron Scattering Center, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Hudak, Michael R.; Lerner, Allan [Earth and Environmental Sciences Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Grubbs, Robert K. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185 (United States); Wang, Shanmin [Lujan Neutron Scattering Center, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Zhang, Zhan; Karapetrova, Evguenia [Advance Photon Source, Argonne National Laboratory, 9700S Cass Ave, Argonne, IL 60439 (United States); Hickmott, Donald [Earth and Environmental Sciences Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Majewski, Jaroslaw, E-mail: jarek@lanl.gov [Lujan Neutron Scattering Center, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)

    2014-08-28

    Carbonates are one of the most abundant groups of minerals in earth systems and are important in many geological settings and industrial processes. Calcite (CaCO{sub 3}) thin films produced by atomic layer deposition offer a method to evaluate the surficial properties of carbonates as well as interactions at the carbonate–fluid interface. Using synchrotron X-ray reflectivity and X-ray diffraction, these films are observed to be porous, polycrystalline, and have crystallites oriented with the major (104) calcite cleavage plane parallel to the surface of the z-cut single crystal quartz substrate. An Al{sub 2}O{sub 3} buffer layer, present between quartz and the calcite film, does not affect the as-deposited film, but does influence how the films reorganize in contact with fluid. Without a buffer layer, calcite reorients its crystallites to have populations of (006) and (030) parallel to the substrate, while those with an Al{sub 2}O{sub 3} buffer layer become more amorphous. Amorphous films may represent an analog to amorphous calcium carbonate and provide insights into that material's thermophysical behavior. Due to a higher percentage of pore spaces available for fluid infiltration, films deposited at higher temperature make the calcite thin films more susceptible to amorphization. These films are chemically similar, but structurally dissimilar to bulk natural calcite. Nevertheless, they can be a complementary system to traditional single crystal X-ray surface scattering studies on carbonates, particularly for important but less common minerals, to evaluate mineral–fluid interfacial interactions. - Highlights: • Atomic layer deposition (ALD) used to produce calcite films. • Calcite film orientation and crystallinity depend on ALD parameters. • ALD calcite films can be both crystalline and amorphous. • Interaction of water with films can re-orient or amorphize the films. • ALD calcite films may be useful to study carbonate–fluid interfacial

  2. X-ray scattering of calcite thin films deposited by atomic layer deposition: Studies in air and in calcite saturated water solution

    International Nuclear Information System (INIS)

    Wang, Peng; Hudak, Michael R.; Lerner, Allan; Grubbs, Robert K.; Wang, Shanmin; Zhang, Zhan; Karapetrova, Evguenia; Hickmott, Donald; Majewski, Jaroslaw

    2014-01-01

    Carbonates are one of the most abundant groups of minerals in earth systems and are important in many geological settings and industrial processes. Calcite (CaCO 3 ) thin films produced by atomic layer deposition offer a method to evaluate the surficial properties of carbonates as well as interactions at the carbonate–fluid interface. Using synchrotron X-ray reflectivity and X-ray diffraction, these films are observed to be porous, polycrystalline, and have crystallites oriented with the major (104) calcite cleavage plane parallel to the surface of the z-cut single crystal quartz substrate. An Al 2 O 3 buffer layer, present between quartz and the calcite film, does not affect the as-deposited film, but does influence how the films reorganize in contact with fluid. Without a buffer layer, calcite reorients its crystallites to have populations of (006) and (030) parallel to the substrate, while those with an Al 2 O 3 buffer layer become more amorphous. Amorphous films may represent an analog to amorphous calcium carbonate and provide insights into that material's thermophysical behavior. Due to a higher percentage of pore spaces available for fluid infiltration, films deposited at higher temperature make the calcite thin films more susceptible to amorphization. These films are chemically similar, but structurally dissimilar to bulk natural calcite. Nevertheless, they can be a complementary system to traditional single crystal X-ray surface scattering studies on carbonates, particularly for important but less common minerals, to evaluate mineral–fluid interfacial interactions. - Highlights: • Atomic layer deposition (ALD) used to produce calcite films. • Calcite film orientation and crystallinity depend on ALD parameters. • ALD calcite films can be both crystalline and amorphous. • Interaction of water with films can re-orient or amorphize the films. • ALD calcite films may be useful to study carbonate–fluid interfacial interactions

  3. X-ray diffraction from thin films : Residual stress and texture analysis

    Energy Technology Data Exchange (ETDEWEB)

    Leoni, M; Scardi, [Trento Univ. (Italy). Dept. of Materials Engineering

    1996-09-01

    In this short contribution the attention will be drawn to the use of XRD-based non-destructive techniques for the study of the stress state and the orientation (texture) of various technologically valuable films. The cases in which the texture is important will be presented and they are: applicative examples, spacing in a wide variety of application areas and regarding growth-induced and machining-induced orientation.

  4. X-ray magnetic circular dichroism study of epitaxial magnetite ultrathin film on MgO(100)

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W. Q.; Xu, Y. B., E-mail: yongbing.xu@york.ac.uk, E-mail: rzhang@nju.edu.cn [York-Nanjing International Center for Spintronics (YNICS), School of Electronics Science and Engineering, Nanjing University, Nanjing 210093 (China); Spintronics and Nanodevice Laboratory, Department of Electronics, University of York, York YO10 5DD (United Kingdom); Song, M. Y.; Lin, J. G. [Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan (China); Maltby, N. J.; Li, S. P. [Spintronics and Nanodevice Laboratory, Department of Electronics, University of York, York YO10 5DD (United Kingdom); Samant, M. G.; Parkin, S. S. P. [IBM Research Division, Almaden Research Center, San Jose, California 95120 (United States); Bencok, P.; Steadman, Paul; Dobrynin, Alexey [Diamond Light Source, Didcot OX11 0DE (United Kingdom); Zhang, R., E-mail: yongbing.xu@york.ac.uk, E-mail: rzhang@nju.edu.cn [York-Nanjing International Center for Spintronics (YNICS), School of Electronics Science and Engineering, Nanjing University, Nanjing 210093 (China)

    2015-05-07

    The spin and orbital magnetic moments of the Fe{sub 3}O{sub 4} epitaxial ultrathin film synthesized by plasma assisted simultaneous oxidization on MgO(100) have been studied with X-ray magnetic circular dichroism. The ultrathin film retains a rather large total magnetic moment, i.e., (2.73 ± 0.15) μ{sub B}/f.u., which is ∼70% of that for the bulk-like Fe{sub 3}O{sub 4}. A significant unquenched orbital moment up to 0.54 ± 0.05 μ{sub B}/f.u. was observed, which could come from the symmetry breaking at the Fe{sub 3}O{sub 4}/MgO interface. Such sizable orbital moment will add capacities to the Fe{sub 3}O{sub 4}-based spintronics devices in the magnetization reversal by the electric field.

  5. Initial surface film on magnesium metal: A characterization by X-ray photoelectron spectroscopy (XPS) and photocurrent spectroscopy (PCS)

    International Nuclear Information System (INIS)

    Santamaria, M.; Di Quarto, F.; Zanna, S.; Marcus, P.

    2007-01-01

    A detailed investigation of the initial film grown on mechanically polished Mg electrodes has been carried out by ex situ X-ray Photoelectron Spectroscopy (XPS) and in situ Photocurrent Spectroscopy (PCS), allowing to reach a detailed picture of the passive layer structure. The XPS data show that the films formed soon after mechanical treatment and immersion in aqueous electrolyte have a bilayer structure, consisting of an ultra-thin MgO inner layer (∼2.5 nm) and a Mg(OH) 2 external layer. The thickness of the Mg(OH) 2 layer is a function of immersion time and solution temperature. After mechanical treatment and immersion in aqueous solution at room temperature, the MgO/Mg(OH) 2 layer in some area of electrodes is so thin to allow an electron photoemission process from the Mg Fermi level to the electrolyte conduction band. Only internal photoemission processes are evidenced for Mg electrodes aged in NaOH at 80 deg. C, due the formation of a thicker Mg(OH) 2 layer. From anodic photocurrent spectra an optical band gap of ∼4.25 eV has been estimated for Mg(OH) 2 , lower with respect to the optical gap of the corresponding anhydrous counterpart

  6. Sensitivity of UF-R, UF-VCh, UF-VR films used for soft x-ray (lambda=2+10A) detection

    International Nuclear Information System (INIS)

    Aglitskij, E.V.; Bojko, V.A.; Kalinkina, T.A.

    1975-01-01

    The sensitometric characteristics of the following types of photographic film were measured in the range of wavelengths 2-10A: UF-R, UF-VCh, and UF-VR. It was demonstrated that UF-VR photographic film is four times as sensitive as UF-R film and 1.6 times as sensitive as UF-VCh film; it is also most suitable film for x-ray spectroscopy of multiply charged ions and for diagnosing high-temperature laser plasma

  7. British Standard method for determination of ISO speed and average gradient of direct-exposure medical and dental radiographic film/process combinations

    International Nuclear Information System (INIS)

    1983-01-01

    Under the direction of the Cinematography and Photography Standards Committee, a British Standard method has been prepared for determining ISO speed and average gradient of direct-exposure medical and dental radiographic film/film-process combinations. The method determines the speed and gradient, i.e. contrast, of the X-ray films processed according to their manufacturer's recommendations. (U.K.)

  8. Development of a concept for radiation patients exposure assessment during dental X-ray examinations and statistical data acquisition for the determination of a diagnostic reference value; Erarbeitung eines Konzepts zur Ermittlung der Strahlenexposition von Patienten bei zahnmedizinischen Roentgenuntersuchungen und Erhebung von statistischen Daten zur Erstellung diagnostischer Referenzwerten

    Energy Technology Data Exchange (ETDEWEB)

    Kueppers, C.; Sering, M. [Oekoinstitut Freiburg e.V., Freiburg (Germany); Poppe, B.; Poplawski, A.; Looe, H.K.; Beyer, D.; Pfaffenberger, A.; Chofor, N.; Eenboom, F. [Pius Hospital, Oldenburg (Germany)

    2012-02-15

    The research project on the development a concept for radiation patients exposure assessment during dental X-ray examinations and statistical data acquisition for the determination of a diagnostic reference value includes the following issues: Fundamental facts: dental X-ray examination techniques, dose relevant factors and characteristics during X-ray examinations, radiation exposed organs during dental X-ray examinations, dose assessment based on phantoms. Materials and methodologies of the project: TLD measurements using the phantom, calculation of the effective dose during dental X-ray examinations, properties and settings of the reference facilities for the determination of radiation exposure, selection of dental offices, dosimetric measurements, data acquisition and statistical evaluation. Results of dosimetric examinations: results of dosimetric measurements at reference facilities, results of dosimetric measurements in dental offices. Discussion of the concept for the determination of the radiation exposure during dental X-ray examinations.

  9. Wiener spectral effects of spatial correlation between the sites of characteristic x-ray emission and reabsorption in radiographic screen-film systems

    Energy Technology Data Exchange (ETDEWEB)

    Metz, C E; Vyborny, C J [Chicago Univ., IL (USA). Dept. of Radiology

    1983-05-01

    When characteristic x-rays are generated and reabsorbed in the phosphor of a radiographic screen-film system, the positions at which light is emitted from the initial and secondary interactions are correlated. A simple statistical model is developed to account for the effect of this correlation on the Wiener spectrum of quantum mottle. Unlike previous models, which ignore spatial correlation, the new model predicts that not only noise magnitude but also noise texture is changed as the incident x-ray energy exceeds the phosphor K-edge.

  10. X-ray analysis of spintronic semiconductor and half metal thin film systems; Roentgenstrukturuntersuchungen an spintronischen Halbleiter- und Halbmetall-Duennschichtsystemen

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, Andreas

    2010-07-01

    In this work the structural properties of spintronic semiconductor and halfmetalic thin-film systems were investigated. The layer thicknesses and interface roughnesses of the multi-layer systems were estimated by X-ray reflectivity measurements. The fits were performed using the software Fewlay which uses the Parratt formalism to calculate the reflectivities. The relaxation of the films was analyzed by reciprocal space mapping on preferably highly indexed Bragg reflexes. (orig.)

  11. TU-FG-209-09: Mathematical Estimation and Experimental Measurement of Patient Free-In-Air Skin Entrance Exposure During a Panoramic Dental X-Ray Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Errico, A; Behrman, R; Li, B [Boston University Medical Center, Boston, MA (United States)

    2016-06-15

    Purpose: To develop a simple mathematical model for estimating the patient free-in-air skin entrance exposure (SEE) during a panoramic dental x-ray that does not require the use of a head phantom. This eliminates issues associated with phantom centering and the mounting of a detector on the phantom for routine QC testing. Methods: We used a Sirona Orthophos XG panoramic radiographic unit and a Radcal Accu-Gold system for this study. A solid state detector was attached over the slit of the Orthophos’ sensor with the help of a custom-built jig. A single measurement of the free-in-air exposure at this position was taken over a full panoramic scan. A mathematical model for estimating the SEE was developed based upon this measurement, the system geometry, x-ray field beam width, and x-ray sweep angle. To validate the model, patient geometry was simulated by a 16 cm diameter PMMA CTDI phantom centered at the machine’s isocenter. Measurements taken on the phantom’s surface were made using a solid state detector with lead backing, an ion chamber, and the ion chamber with the phantom wrapped in lead to mitigate backscatter. Measurements were taken near the start position of the tube and at 90 degrees from the start position. Results: Using the solid state detector, the average SEE was 23.5+/−0.02 mR and 55.5+/−0.08 mR at 64 kVp and 73 kVp, respectively. With the lead-wrapping, the measurements from the ion chamber matched those of the solid state detector to within 0.1%. Preliminary results gave the difference between the mathematical model and the phantom measurements to be approximately 5% at both kVps. Conclusion: Reasonable estimates of patient SEE for panoramic dental radiography can be made using a simple mathematical model without the need for a head phantom.

  12. TU-FG-209-09: Mathematical Estimation and Experimental Measurement of Patient Free-In-Air Skin Entrance Exposure During a Panoramic Dental X-Ray Procedure

    International Nuclear Information System (INIS)

    Errico, A; Behrman, R; Li, B

    2016-01-01

    Purpose: To develop a simple mathematical model for estimating the patient free-in-air skin entrance exposure (SEE) during a panoramic dental x-ray that does not require the use of a head phantom. This eliminates issues associated with phantom centering and the mounting of a detector on the phantom for routine QC testing. Methods: We used a Sirona Orthophos XG panoramic radiographic unit and a Radcal Accu-Gold system for this study. A solid state detector was attached over the slit of the Orthophos’ sensor with the help of a custom-built jig. A single measurement of the free-in-air exposure at this position was taken over a full panoramic scan. A mathematical model for estimating the SEE was developed based upon this measurement, the system geometry, x-ray field beam width, and x-ray sweep angle. To validate the model, patient geometry was simulated by a 16 cm diameter PMMA CTDI phantom centered at the machine’s isocenter. Measurements taken on the phantom’s surface were made using a solid state detector with lead backing, an ion chamber, and the ion chamber with the phantom wrapped in lead to mitigate backscatter. Measurements were taken near the start position of the tube and at 90 degrees from the start position. Results: Using the solid state detector, the average SEE was 23.5+/−0.02 mR and 55.5+/−0.08 mR at 64 kVp and 73 kVp, respectively. With the lead-wrapping, the measurements from the ion chamber matched those of the solid state detector to within 0.1%. Preliminary results gave the difference between the mathematical model and the phantom measurements to be approximately 5% at both kVps. Conclusion: Reasonable estimates of patient SEE for panoramic dental radiography can be made using a simple mathematical model without the need for a head phantom.

  13. A statistical survey of x-ray CT cases at the Clinic of Oral and Maxillofacial Radiology, Chiba Hospital, Tokyo Dental College

    International Nuclear Information System (INIS)

    Kitagawa, Hiromi; Wakoh, Mamoru; Shibuya, Hitoshi; Yamada, Masayuki; Harada, Takuya; Yamamoto, Kazuhiro; Makihara, Masahiro; Kuroyanagi, Kinya

    1997-01-01

    Statistical study was performed of x-ray CT cases at the Clinic of Oral and Maxillofacial Radiology, Chiba Hospital, Tokyo Dental College since a Toshiba CT Scanner TCT-700S was settled in 1988, until December 1994. Total number of cases photographed was 2645 cases, Male; 1447 (54.7%), Female; 1198 cases (45.3%). Total number of cases yearly photographed have increased every year. 95.43% of the cases were the diseases of oral surgery regions. X-ray CT has been used to malignant tumors (730 cases; 29.7%), cyst (435 cases; 17.7%), inflammation (362 cases; 14.7%), benign tumors (261 cases; 10.6%), injury (171 cases; 7.0%), salivary gland diseases (126 cases; 5.1%) and others. The number of tumors and cyst have been increasing every year. Average number of slices in every diseases were counted. Malignant tumor, injury, temporomandibular joint diseases, and congenital anomalies and malformations were counted many slices. Percentages of number of enhanced CT cases have been increased every year. Recently, number of enhanced CT cases have more number than non-enhanced CT cases. This attitude is correlated with the number of malignant tumors which have been increasing every year. Total number of cases of three dimensional imaging CT (3D-CT) was 316 cases. 3D-CT has been used to injury (146 cases; 46.2%), temporomandibular joint diseases (52 cases; 16.4%), congenital anomalies and malformations (49 cases; 15.5%), tumors (21 cases; 6.7%), cyst (13 cases; 4.1%) and others. The need of x-ray CT in our field and the tendency of dental treatment at Chiba Hospital might be changed in the future. In order to this situation, this type of statistical study will be performed again. (author)

  14. Imaging Nanometer Phase Coexistence at Defects During the Insulator-Metal Phase Transformation in VO2 Thin Films by Resonant Soft X-ray Holography.

    Science.gov (United States)

    Vidas, Luciana; Günther, Christian M; Miller, Timothy A; Pfau, Bastian; Perez-Salinas, Daniel; Martínez, Elías; Schneider, Michael; Gührs, Erik; Gargiani, Pierluigi; Valvidares, Manuel; Marvel, Robert E; Hallman, Kent A; Haglund, Richard F; Eisebitt, Stefan; Wall, Simon

    2018-05-18

    We use resonant soft X-ray holography to image the insulator-metal phase transition in vanadium dioxide with element and polarization specificity and nanometer spatial resolution. We observe that nanoscale inhomogeneity in the film results in spatial-dependent transition pathways between the insulating and metallic states. Additional nanoscale phases form in the vicinity of defects which are not apparent in the initial or final states of the system, which would be missed in area-integrated X-ray absorption measurements. These intermediate phases are vital to understand the phase transition in VO 2 , and our results demonstrate how resonant imaging can be used to understand the electronic properties of phase-separated correlated materials obtained by X-ray absorption.

  15. Performance of a gaseous detector based energy dispersive X-ray fluorescence imaging system: Analysis of human teeth treated with dental amalgam

    Science.gov (United States)

    Silva, A. L. M.; Figueroa, R.; Jaramillo, A.; Carvalho, M. L.; Veloso, J. F. C. A.

    2013-08-01

    Energy dispersive X-ray fluorescence (EDXRF) imaging systems are of great interest in many applications of different areas, once they allow us to get images of the spatial elemental distribution in the samples. The detector system used in this study is based on a micro patterned gas detector, named Micro-Hole and Strip Plate. The full field of view system, with an active area of 28 × 28 mm2 presents some important features for EDXRF imaging applications, such as a position resolution below 125 μm, an intrinsic energy resolution of about 14% full width at half maximum for 5.9 keV X-rays, and a counting rate capability of 0.5 MHz. In this work, analysis of human teeth treated by dental amalgam was performed by using the EDXRF imaging system mentioned above. The goal of the analysis is to evaluate the system capabilities in the biomedical field by measuring the drift of the major constituents of a dental amalgam, Zn and Hg, throughout the tooth structures. The elemental distribution pattern of these elements obtained during the analysis suggests diffusion of these elements from the amalgam to teeth tissues.

  16. X-ray refractometer

    International Nuclear Information System (INIS)

    Tur'yanskij, A.G.; Pirshin, I.V.

    2001-01-01

    Paper introduces a new circuit of X-ray refractometer to study angular and spectral features of refracted radiation within hard X-ray range. Refractometer incorporates two goniometers, two crystal-analyzers and three radiation detectors. The maximum distance between radiation source focal point and a receiving slit of the second goniometer is equal to 1.4 m. For the first time one obtained refraction patterns of fine-film specimens including C/Si stressed structure. Paper describes a new technique of refractometry via specimen oscillation at fixed position of a detecting device. Paper presents the measurement results of oscillation refraction patterns for specimens of melted quartz and ZnSe single crystal [ru

  17. Analysis of causes for reject x-ray films as a quality assurance elements in diagnostic radiology in Jos university teaching hospital

    International Nuclear Information System (INIS)

    Anikoh, S.O.; Mangset, W.E.; Habila, N.; Mallam, S.P.

    2010-01-01

    The film reject rate and quality assessments studies were carried out at the Jos University Teaching Hospital. The rejected films collected and counted with respect to type, size and reasons for rejection were carried out for two calendar years. The observed reject rates were found to be nearly independent of the type of X-ray examination, which 68% of waste film reflected the nature and skills employed. The mechanical influence of equipment (machine fault is 11%, film rejection due to poor processing (dark room fault) was found to be 8% and for film rejection due to wrong identification, fogged film, uncooperating patient (patient movement) are 5%, 5% and 3% respectively. The deterioration in the quality of films and film processing conditions, ineffective quality assurance programs and inadequate regular staff training form a possible explanation for observed waste films which could have been avoided.

  18. Mechanical design of thin-film diamond crystal mounting apparatus with optimized thermal contact and crystal strain for coherence preservation x-ray optics

    Science.gov (United States)

    Shu, Deming; Shvydko, Yury; Stoupin, Stanislav; Kim, Kwang-Je

    2018-05-08

    A method and mechanical design for a thin-film diamond crystal mounting apparatus for coherence preservation x-ray optics with optimized thermal contact and minimized crystal strain are provided. The novel thin-film diamond crystal mounting apparatus mounts a thin-film diamond crystal supported by a thick chemical vapor deposition (CVD) diamond film spacer with a thickness slightly thicker than the thin-film diamond crystal, and two groups of thin film thermal conductors, such as thin CVD diamond film thermal conductor groups separated by the thick CVD diamond spacer. The two groups of thin CVD film thermal conductors provide thermal conducting interface media with the thin-film diamond crystal. A piezoelectric actuator is integrated into a flexural clamping mechanism generating clamping force from zero to an optimal level.

  19. High performance imaging of relativistic soft X-ray harmonics by sub-micron resolution LiF film detectors

    Energy Technology Data Exchange (ETDEWEB)

    Pikuz, Tatiana; Faenov, Anatoly [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Pirozhkov, Alexander; Esirkepov, Timur; Koga, James; Nakamura, Tatsufumi; Bulanov, Sergei; Fukuda, Yuji; Hayashi, Yukio; Kotaki, Hideyuki; Kando, Masaki [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Astapov, Artem; Pikuz, Sergey Jr. [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Klushin, Georgy [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); International Laser Center of M.V. Lomonosov Moscow State University, Moscow (Russian Federation); Nagorskiy, Nikolai; Magnitskiy, Sergei [International Laser Center of M.V. Lomonosov Moscow State University, Moscow (Russian Federation); Kato, Yoshiaki [The Graduate School for the Creation of New Photonics Industries, Hamamatsu, Shizuoka (Japan)

    2012-12-15

    The spectrum variation and the coherent properties of the high-order harmonics (HOH) generated by an oscillating electron spikes formed at the joint of the boundaries of a cavity and a bow wave, which are created by a relativistically self-focusing laser in underdense gas jet plasma, are investigated. This new mechanism for HOH generation efficiently produces emission from ultraviolet up to the XUV ''water window'' spectral range. To characterize such source in the wide spectral range a diffraction imaging technique is applied. High spatial resolution EUV and soft X-ray LiF film detector have been used for precise measurements of diffraction patterns. The measurements under observation angle of 8 to the axis of laser beam propagation have been performed. The diffraction patterns were observed on the detector clearly, when the square mesh was placed at the distance of 500 mm from the output of plasma and at the distance of 27.2 mm in front of the detector. It is shown that observed experimental patterns are well consistent with modeled ones for theoretical HOH spectrum, provided by particle-in-cell simulations of a relativistic-irradiance laser pulse interaction with underdense plasma (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Quantitative analysis of povidone-iodine thin films by X-ray photoelectron spectroscopy and their physicochemical properties

    Directory of Open Access Journals (Sweden)

    Sa Anongtip

    2017-06-01

    Full Text Available In this study, povidone-iodine (PVP-I has been formulated as a topical spray to produce a thin film for the controlled release of I2. By means of experimental design, 27 formulations containing glycerol, ethanol, PEG 400, copovidone and HFA 134a as a propellant were prepared. The pH values of all formulations were in the range of 6-7. The viscosity was within the range of 11.9-85.9 mPa s. The surface tensions were 20.3 to 24.6 mN m-1 and the contact angles were between 19.3 and 38.7°. The assays for the iodine contents were within acceptable range (80-120 %. X-ray photoelectron spectroscopy analysis revealed the ionized form of iodine was much higher than the unionized form. The MIC and MBC values of the PVP-I sprays against Staphylococcus aureus, S. epidermidis and Pseudomonas aeruginosa were higher than that of commercial PVP-I solution. The cytotoxicity study confirmed that the PVP-I spray had lower toxic effects on keratinocytes and fibroblasts compared to the commercial PVP-I solution. The formulation containing 59 % ethanol, 18 % copovidone and 12 % PEG 400 showed good antibacterial activity.

  1. Patient dose map indications on interventional X-ray systems and validation with Gafchromic XR-RV3 film

    International Nuclear Information System (INIS)

    Bordier, C.; Klausz, R.; Desponds, L.

    2015-01-01

    To help avoiding secondary effects of interventional procedures like skin damage, a dose map method has been developed to provide an indication of the local dose on a surface representative of individual patient shapes. To minimise user interactions, patient envelope shapes are automatically determined depending on simple patient data information. Local doses are calculated in 1-cm 2 areas depending on the estimated air kerma, table and gantry positions and system settings, taking into account the table and mattress attenuations and estimated backscatter from the patient. These local doses are cumulated for each location of the patient envelope during the clinical procedure. To assess the accuracy of the method, Gafchromic XR-RV3 films have been used in several operating configurations. Good visual agreements on cumulated dose localisation were obtained within the 1-cm 2 precision of the map and the dose values agreed within 24.9 % accuracy. The resulting dose map method has been integrated into GE Healthcare X-Ray angiographic systems and should help in the management of the dose by the users during the procedure. (authors)

  2. X-Ray

    Science.gov (United States)

    ... enema. What you can expect During the X-ray X-rays are performed at doctors' offices, dentists' offices, ... as those using a contrast medium. Your child's X-ray Restraints or other techniques may be used to ...

  3. Chest X-Ray

    Medline Plus

    Full Text Available ... talk with you about chest radiography also known as chest x-rays. Chest x-rays are the ... treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray ...

  4. Growth and structure of water on SiO2 films on Si investigated byKelvin probe microscopy and in situ X-ray Spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Verdaguer, A.; Weis, C.; Oncins, G.; Ketteler, G.; Bluhm, H.; Salmeron, M.

    2007-06-14

    The growth of water on thin SiO{sub 2} films on Si wafers at vapor pressures between 1.5 and 4 torr and temperatures between -10 and 21 C has been studied in situ using Kelvin Probe Microscopy and X-ray photoemission and absorption spectroscopies. From 0 to 75% relative humidity (RH) water adsorbs forming a uniform film 4-5 layers thick. The surface potential increases in that RH range by about 400 mV and remains constant upon further increase of the RH. Above 75% RH the water film grows rapidly, reaching 6-7 monolayers at around 90% RH and forming a macroscopic drop near 100%. The O K-edge near-edge X-ray absorption spectrum around 75% RH is similar to that of liquid water (imperfect H-bonding coordination) at temperatures above 0 C and ice-like below 0 C.

  5. A New Development in the Method of Measurement of Reciprocity-Law Failure and Its Application to Screen/Green-Sensitive X-Ray Film Systems

    Science.gov (United States)

    Fujita, Hiroshi; Uchida, Suguru

    1981-01-01

    Since it has been confirmed by experiment that the intensity of X-rays varies approximately as the focus-film distance (FFD) to the minus 2.12th power, the X-ray intensity can be changed by varying the FFD. It is shown in this paper that two types of reciprocity failure curve, density vs. exposure time for constant exposure and relative exposure vs. exposure time for constant density, can easily be obtained from several time-scale characteristic curves taken experimentally for several FFD’s in the rare-earth screen-film systems used. Only low-intensity reciprocity failure is present for exposure times of more than about 0.1 sec for one film, but both low-intensity and high-intensity reciprocity failures occur in the other one. The effects of reciprocity failure on the H & D curves can be seen in the shape of the curves and the relative speed.

  6. A new development in the method of measurement of reciprocity-law failure and its application to screen/green-sensitive x-ray film systems

    International Nuclear Information System (INIS)

    Fujita, Hiroshi; Uchida, Suguru.

    1981-01-01

    Since it has been confirmed by experiment that the intensity of X-rays varies approximately as the focus-film distance (FFD) to the minus 2.12th power, the X-ray intensity can be changed by varying the FFD. It is shown in this paper that two types of reciprocity failure curve, density vs. exposure time for constant exposure and relative exposure vs. exposure time for constant density, can easily be obtained from several time-scale characteristic curves taken experimentally for several FFD's in the rare-earth screen-film systems used. Only low-intensity reciprocity failure is present for exposure times of more than about 0.1 sec for one film, but both low-intensity and high-intensity reciprocity failures occur in the other one. The effects of reciprocity failure on the H D curves can be seen in the shape of the relative speed. (author)

  7. X-ray fluorescence holography

    CERN Document Server

    Hayashi, K; Takahashi, Y

    2003-01-01

    X-ray fluorescence holography (XFH) is a new structural analysis method of determining a 3D atomic arrangement around fluorescing atoms. We developed an XFH apparatus using advanced X-ray techniques and succeeded in obtaining high-quality hologram data. Furthermore, we introduced applications to the structural analysis of a thin film and the environment around dopants and, discussed the quantitative analysis of local lattice distortion. (author)

  8. Development of porous plug phase separator and superfluid film flow suppression system for the Soft X-ray Spectrometer onboard ASTRO-H

    Science.gov (United States)

    Ezoe, Yuichiro; Ishikawa, Kumi; Ohashi, Takaya; Yamaguchi, Hiroya; Mitsuda, Kazuhisa; Fujimoto, Ryuichi; Murakami, Masahide; Kanao, Kenichi; Yoshida, Seiji; Tsunematsu, Shoji; DiPirro, Michael; Shirron, Peter; the SXS Team

    2012-04-01

    ASTRO-H is the sixth Japanese astronomy satellite scheduled for launch in 2014. The Soft X-ray Spectrometer instrument is onboard ASTRO-H. This is a 6 × 6 array of X-ray microcalorimeters with an energy resolution of gravity, a porous plug phase separator made of sintered stainless is used. Since the vapor mass flow rate is only 29 μg/s, any additional superfluid film loss influences the lifetime of the liquid helium. Therefore, a film flow suppression system consisting of an orifice, a heat exchanger, and knife edge devices is adopted based on the design used for the X-ray Spectrometer onboard Suzaku. The film flow will be suppressed to <2 μg/s, sufficiently smaller than the vapor flow rate. In the present investigation, the design and ground experiments of a helium vent system composed of the porous plug and film flow suppression system are presented. The results show that the phase separation and the film flow suppression are satisfactorily achieved.

  9. X-ray astronomy

    International Nuclear Information System (INIS)

    Giacconi, R.; Gursky, H.

    1974-01-01

    This text contains ten chapters and three appendices. Following an introduction, chapters two through five deal with observational techniques, mechanisms for the production of x rays in a cosmic setting, the x-ray sky and solar x-ray emission. Chapters six through ten include compact x-ray sources, supernova remnants, the interstellar medium, extragalactic x-ray sources and the cosmic x-ray background. Interactions of x rays with matter, units and conversion factors and a catalog of x-ray sources comprise the three appendices. (U.S.)

  10. Analysis of image factors of x-ray films : study for the intelligent replenishment system of automatic film processor

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Tae; Yoon, Chong Hyun; Park, Kwang BO; Auh, Yong Ho; Lee, Hyoung Jin; In, Kyung Hwan; Kim, Keon Chung [Asan Medical Center, Ulsan Univ. College of Medicine, Ulsan (Korea, Republic of)

    1998-06-01

    We analyzed image factors to determine the characteristic factors that need for intelligent replenishment system of the auto film processor. We processed the serial 300 sheets of radiographic films of chest phantom without replenishment of developing and fixation replenisher. We took the digital data by using film digitizer which scanned the films and automatically summed up the pixel values of the films. We analyzed characteristic curves, average gradients and relative speeds of individual film using densitometer and step densitometry. We also evaluated the pH of developer, fixer, and washer fluid with digital pH meter. Fixer residual rate and washing effect were measured by densitometer using the reagent methods. There was no significant reduction of the digital density numbers of the serial films without replenishment of developer and fixer. The average gradients were gradually decreased by 0.02 and relative speeds were also gradually decreased by 6.96% relative to initial standard step-densitometric measurement. The pHs of developer and fixer were reflected the inactivation of each fluid. The fixer residual rates and washing effects after processing each 25 sheets of films were in the normal range. We suggest that the digital data are not reliable due to limitation of the hardware and software of the film digitizer. We conclude that average gradient and relative speed which mean the film's contrast and sensitivity respectively are reliable factors for determining the need for the replenishment of the auto film processor. We need more study of simpler equations and programming for more intelligent replenishment system of the auto film processor.

  11. Evaluation the image obtained from X-ray flat-panel detectors utilizing a polycrystalline CdZnTe film as the conversion layer

    International Nuclear Information System (INIS)

    Tokuda, S.; Kishihara, H.; Kaino, M.; Sato, T.

    2006-01-01

    We can expect that fluoroscopic images with a high sensitivity and excellent detective efficiency can be obtained by using a semiconductor with a small W factor for the conversion layer of X-ray flat-panel detectors, which have experienced a rapid gain inpopularity for medical and non-destructive industrial inspection uses in recent years. We believe that polycrystalline CdZnTe film formed by the closed spaced sublimation (CSS) method is a promising conversion material for next-generation high efficiency X-ray flat-panel detectors, and have previously reported the results of feasibility studies. In this paper, we present an overview of X-ray flat-panel detectors and the features of CdZnTe film, then we describe the CSS method of deposition and evaluation of the physical characteristics of CdZnTe film, and finally we present the results of our fabrication and testing of proto-type detectors utilizing CdZnTe film. (author)

  12. Locally resolved investigation of wedged Cu(In,Ga)Se{sub 2} films prepared by physical vapor deposition using hard X-ray photoelectron and X-ray fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Calvet, Wolfram, E-mail: wolfram.calvet@helmholtz-berlin.de [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Ümsür, Bünyamin; Höpfner, Britta; Lauermann, Iver; Prietzel, Karsten; Kaufmann, Christan A.; Unold, Thomas [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Lux-Steiner, Martha C. [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Freie Universität Berlin, Department of Physics, Arnimallee 14, D-14195 Berlin (Germany)

    2015-05-01

    We have investigated a specially grown Cu(In,Ga)Se{sub 2} (CIGSe) absorber, which was deposited by co-evaporation of Cu, In, Ga, and Se using a modified three stage process. Prior to the growth, the molybdenum-coated glass substrate was covered by a bent shroud made from tantalum (Ta), leading to a wedged absorber structure with a width of about 2 mm where the film thickness varies from 0 to 2 μm. In this region of interest the thickness dependency of morphology, concentration ratios and electronic properties was studied with secondary electron microscopy (SEM), X-ray fluorescence (XRF) and hard X-ray photoelectron spectroscopy (HAXPES), probing the CIGSe sample along the thickness gradient. The evidence of the thickness gradient itself was proven with SEM measurements in cross section geometry. By using XRF it was found that with decreasing film thickness the Cu concentration decreases significantly. This finding was also verified by HAXPES measurements. Furthermore, an enrichment of Ga towards the Mo back contact was found using the same technique. Besides these results the formation of a molybdenum selenide (MoSe) phase was observed on the fully covered part of the Mo coated substrate indicating a high mobility of Se on Mo under the given temperature conditions of the modified three stage deposition process. - Highlights: • Growth of a CIGSe wedge • Application of HAXPES and XRF as local probing techniques • Good agreement with former studies • Wedged CIGSe structures can be used for further, locally resolved experiments.

  13. Determination of the Mass Absorption Coefficient in Two-Layer Ti/V and V/Ti Thin Film Systems by the X-Ray Fluorescence Method

    Science.gov (United States)

    Mashin, N. I.; Chernyaeva, E. A.; Tumanova, A. N.; Gafarova, L. M.

    2016-03-01

    A new XRF procedure for the determination of the mass absorption coefficient in thin film Ti/V and V/Ti two-layer systems has been proposed. The procedure uses easy-to-make thin-film layers of sputtered titanium and vanadium on a polymer film substrate. Correction coefficients have been calculated that take into account attenuation of primary radiation of the X-ray tube, as well as attenuation of the spectral line of the bottom layer element in the top layer.

  14. Electron-Beam Deposition of Superconducting Molybdenum Thin Films for the Development of Mo/Au TES X-Ray Microcalorimeter

    Science.gov (United States)

    Finkbeiner, Fred Michael; Adams, Joseph S.; Bandler, Simon R.; Betancour-Martinez, Gabriele L.; Brown, Ari David; Chang, Meng-Ping; Chervenak, James A.; Chiao, Meng P.; Datesman, Aaron; Eckart, Megan E.; hide

    2016-01-01

    We are exploring the properties of electron-beam evaporated molybdenum thin films on silicon nitride coated silicon wafers at substrate temperatures between room temperature and 650 C. The temperature dependence of film stress, transition temperature, and electrical properties are presented. X-ray diffraction measurements are performed to gain information on molybdenum crystallite size and growth. Results show the dominant influence of the crystallite size on the intrinsic properties of our films. Wafer-scale uniformity, wafer yield, and optimal thermal bias regime for TES fabrication are discussed.

  15. Lattice positions of Sn in Cu2ZnSnS4 nanoparticles and thin films studied by synchrotron X-ray absorption near edge structure analysis

    Science.gov (United States)

    Zillner, E.; Paul, A.; Jutimoosik, J.; Chandarak, S.; Monnor, T.; Rujirawat, S.; Yimnirun, R.; Lin, X. Z.; Ennaoui, A.; Dittrich, Th.; Lux-Steiner, M.

    2013-06-01

    Lattice positions of Sn in kesterite Cu2ZnSnS4 and Cu2SnS3 nanoparticles and thin films were investigated by XANES (x-ray absorption near edge structure) analysis at the S K-edge. XANES spectra were analyzed by comparison with simulations taking into account anti-site defects and vacancies. Annealing of Cu2ZnSnS4 nanoparticle thin films led to a decrease of Sn at its native and defect sites. The results show that XANES analysis at the S K-edge is a sensitive tool for the investigation of defect sites, being critical in kesterite thin film solar cells.

  16. Molecular aggregation states of poly{2-(perfluorooctyl)ethyl acrylate} polymer brush thin film analyzed by grazing incidence X-ray diffraction

    International Nuclear Information System (INIS)

    Yamaguchi, H; Honda, K; Takahara, A; Kobayashi, M; Morita, M; Masunaga, H; Sasaki, S; Takata, M; Sakata, O

    2009-01-01

    Fluoropolymer brush with crystalline side chains was prepared by surface-initiated atom transfer radical polymerization of 2-(perfluorooctyl)ethyl acrylate (FA-C 8 ) from a flat silicon substrate. The crystallization and the molecular aggregation structures of polymer side chain at the outermost surface and internal region in the brush film were characterized by grazing incidence X-ray diffraction (GIXD) measurement using two different incident angles of X-ray. At the air interface of PFA-C 8 brush film, the rod-like R f group was oriented perpendicular to the surface forming a hexagonal packing structure to reduce surface energy. In contrast, the oriented R f groups parallel to the substrate coexisted at the internal region in the brush. This unique depth dependence of crystalline state of the fluoropolymer brush was observed by surface-sensitive GIXD measurement.

  17. Molecular aggregation states of poly{l_brace}2-(perfluorooctyl)ethyl acrylate{r_brace} polymer brush thin film analyzed by grazing incidence X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, H; Honda, K; Takahara, A [Graduate School of Engineering, Kyushu University, Nishi-ku, Fukuoka 819-0395 (Japan); Kobayashi, M [Institute for Materials Chemistry and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Morita, M [Fundamental Research Department, Chemical Division, Daikin Industries, Ltd., 1-1 Nishi Hitotsuya, Settsu-shi, Osaka 566-8585 (Japan); Masunaga, H; Sasaki, S; Takata, M [Japan Synchrotron Research Institute, Mikazuki Sayo, Hyogo 671-5198 (Japan); Sakata, O, E-mail: takahara@cstf.kyushu-u.ac.j [RIKEN Harima Institute, Mikazuki Sayo, Hyogo 671-5198 (Japan)

    2009-08-01

    Fluoropolymer brush with crystalline side chains was prepared by surface-initiated atom transfer radical polymerization of 2-(perfluorooctyl)ethyl acrylate (FA-C{sub 8}) from a flat silicon substrate. The crystallization and the molecular aggregation structures of polymer side chain at the outermost surface and internal region in the brush film were characterized by grazing incidence X-ray diffraction (GIXD) measurement using two different incident angles of X-ray. At the air interface of PFA-C{sub 8} brush film, the rod-like R{sub f} group was oriented perpendicular to the surface forming a hexagonal packing structure to reduce surface energy. In contrast, the oriented R{sub f} groups parallel to the substrate coexisted at the internal region in the brush. This unique depth dependence of crystalline state of the fluoropolymer brush was observed by surface-sensitive GIXD measurement.

  18. Feasibility study for application of the compressed-sensing framework to interior computed tomography (ICT) for low-dose, high-accurate dental x-ray imaging

    Science.gov (United States)

    Je, U. K.; Cho, H. M.; Cho, H. S.; Park, Y. O.; Park, C. K.; Lim, H. W.; Kim, K. S.; Kim, G. A.; Park, S. Y.; Woo, T. H.; Choi, S. I.

    2016-02-01

    In this paper, we propose a new/next-generation type of CT examinations, the so-called Interior Computed Tomography (ICT), which may presumably lead to dose reduction to the patient outside the target region-of-interest (ROI), in dental x-ray imaging. Here an x-ray beam from each projection position covers only a relatively small ROI containing a target of diagnosis from the examined structure, leading to imaging benefits such as decreasing scatters and system cost as well as reducing imaging dose. We considered the compressed-sensing (CS) framework, rather than common filtered-backprojection (FBP)-based algorithms, for more accurate ICT reconstruction. We implemented a CS-based ICT algorithm and performed a systematic simulation to investigate the imaging characteristics. Simulation conditions of two ROI ratios of 0.28 and 0.14 between the target and the whole phantom sizes and four projection numbers of 360, 180, 90, and 45 were tested. We successfully reconstructed ICT images of substantially high image quality by using the CS framework even with few-view projection data, still preserving sharp edges in the images.

  19. Crystallite size and lattice distortion of human dental enamel estimated from the integral width of x-ray diffraction peak profile

    International Nuclear Information System (INIS)

    Maruyama, Fumiaki; Sakae, Toshiro

    2000-01-01

    Crystallite size and lattice distortion of human dental enamel were estimated by peak profile analysis using x-ray diffraction pattern. Firstly, noises were removed from x-ray diffraction pattern, and deconvolution of overlapping peaks and determination of baseline level were carried out. Then, the instrumental peak broadening and effect of overlapping Kα1 and Kα2 were eliminated to obtain pure peak profile using the Stokes's Fourier method. The integral width method was applied for estimation of crystallite size and 'upper-limit of distortion', assuming the peak profile as Cauchy function. The estimated crystallite size and distortion were ca. 210 A and ca. 0.4% in the a-axis direction and ca. 550 A and ca. 0.7% in the c-axis direction, respectively. The crystallite size value along the a-axis was almost the same to the previously reported values, but the value for along the c-axis was nearly half of the reported values. The crystallite size in this study means the size of coherent domain in contrast to the size of particle which may contain several domains in the case of enamel crystals. The results suggest that human enamel crystals grow in their size along the c-axis by multiplication, fusion of crystallites. It was notable that the distortion value was larger in the c-axis direction. The phenomenon may partly be due to the high carbonate ion content of enamel crystals and partly due to crystal growth mechanism. (author)

  20. Chest X-Ray

    Medline Plus

    Full Text Available ... about chest radiography also known as chest x-rays. Chest x-rays are the most commonly performed x-ray exams and use a very small dose of ... of the inside of the chest. A chest x-ray is used to evaluate the lungs, heart and ...