DOCSLIB.ORG

1 605 M (21) Application No

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
1 605 M (21) Application No PATENT SPECIFICATION C») 1 605 m (21) Application No. 47351/77 (22) Filed 14 Nov. 1977 (31) Convention Application No. 741430 (32) Filed 12 Nov. 1976 (31) Convention Application No. 763637 (32) Filed 28 Jan. 1977 in (33) United States of America (US) (44) Complete Specification published 16 Dec. 1981 (51) INT CL3 H01J 31/50 (52) Index at acceptance HID 17C I8C 18LX 18LY 344A2A 4A2Y 4A4 4B44F2C4F2E 4F2Y 4H1X 4HY 4K2B 4K2C 4K2E 4K2Y 4K3B 9C1X 9C1Y 9FX 9 FY 9Y (54) X-RAY IMAGE INTENSIFIER TUBE AND RADIOGRAPHIC CAMERA INCORPORATING SAME (71) We, DIAGNOSTIC INFORM- usually around 350,000 to 700,000 erg/cmJ-R 45 ATION, INC., a corporation organised and or about 50,000 to 100,000 cd-sec/mJ-R, existing under the laws of the State of which is about 5,000 to 10,000 times the California, United States of America, of 246 conversion efficiency of the old-time 5 Sobrante Way, Sunnyvale, California 94086, fluoroscopic screen. Part of this United States of America, do hereby intensification is obtained as true electronic 50 declare the invention for which we pray that gain, which is about 50 to 100 times over the a patent may be granted to us, and the old-time fluoroscopic screen. Another method by which it is to be performed, to be factor of 100 gain is obtained through the 10 particularly described in and by the 100 fold area minification of the image of following statement:— the output screen. 55 The invention pertains to medical x-ray The image quality of such conventional apparatus, and more particularly to an x-ray inverter type image intensifier tube is image intensifier tube for medical x-ray reasonably adequate for fluoroscopic use, 15 diagnostic use, and to a radiographic but is far short of the requirement for camera using such a tube. radiographic use. The requirements for 60 A common present day x-ray image radiographic use are established by the intensifier tube is of the electrostatically conventional film-screen system, which focused inverter type with a 100 fold area demands a 20% modulation transfer 20 minified output image size. This function response at between 2 to 3 line conventional inverter type x-ray image pairs per millimeter. 65 intensifier tube typically has a convexly Such conventional film-screen systems curved, six to nine inch diameter input x-ray are commercially available in speeds" sensitive screen which converts the x-ray ranging from 250 R"1 to 8000 R"1. The speed 25 image into a light image which, in turn, is is defined as the reciprocal of the x-ray converted into electrons which are then exposure in terms of roentgens, R, to the 70 accelerated and electrostatically focused film-screen system to result in a net optical onto an output image screen which is 100 density of 1.0 on the processed film. The times smaller in area than the input screen, spatial resolving ability of the film-screen 30 being typically 0.6 inches to 1.0 inches in system is generally inversely proportional to diameter. The displayed image on' the the speed of the system. That is, the higher 75 output screen can be optically magnified the spatial resolving ability the lower the and coupled to other systems for speed of the system. radiographic or fluoroscopic purposes. For While film-screen systems have desirable 35 example, for radiographic purposes, the system speed qualities, they have the image is optically coupled to a film camera drawback that they require taking full size 80 or a photographic film. For fluoroscopic photos which are difficult to store and purposes, the image can be displayed either which are becoming increasingly more by using a system of mirrors and lenses for expensive due to the rising cost of the silver 40 direct viewing or by using a closed circuit halide x-ray film. Also, the film cannot be television camera and monitor for remote monitored during exposure to control the 85 viewing. dosage or timing. The conversion efficiency of such a A recent article published by C. B. conventional image intensifier system is Johnson in the Proceedings of the Society of 2 1,604,2 2 Photo Optical Instrumentation Engineers, output brightness of the tube starts to Volume 35, pages 3—8 (1973), become sublinear in response with respect hypothetical^ suggests that an x-ray to the input x-ray dose rate. The sublinear sensitive proximity type image intensifier response becomes worse at higher x-ray 5 may be designed with an x-ray sensitive dose rate. This undesirable feature reduces 70 conversion screen on one side of a glass contrast discrimination during fluoroscopy support and a photocathode on the other and is virtually useless for radiography. side of the glass support. However, the Again, it is unknown whether a large format article gives no specifics concerning the beyond six inches in' • diameter, self- 10 critical parameters or what might be used as supporting and with uniform gain, MCP can 75 the x-ray sensitive conversion screen. How be fabricated. this image intensifier can be designed to The Millar proximity type image result in high conversion efficiency or high intensifier tube has a glass envelope and an resolution was also not discussed. inwardly concave, titanium input window. 15 A proximity device using a The window is described as being 0.3 mm 80 michrochannel plate (MCP) both as the thick. Materials such as titanium, aluminum primary x-ray sensitive conversion screen and beryllium cause undesirable scattering and as an electron multiplication device was of the x-rays which reduces the image described by S. Baiter and his associates in quality. Furthermore, because of the 20 Radiology, Volume 110, pages 673—676 relatively high porosity and low tensile 85 (1974), and by Manley et al. in U. S. Patent strength properties of such materials, they no. 3,394,261. According to an article cannot be made with the optimum thickness published by J. Adams in Advances in to maximize their x-ray transmissive Electronics and Electron Physics, Volume properties. Still another problem with tubes 25 22A (Academic Press, 1966), pages 139— constructed with such materials for the 90 153, this type of device has a very low input window and glass for tube envelope is quantum detection efficiency in the in joining the window to the tube envelope. practical medical diagnostic x-ray energy The materials have such dissimilar thermal range of 30—100 Kev. The device gain of expansion properties, among other 30 the Baiter article was first reported to be differences, as to preclude their practical 95 2 20—3 cd-sec/m -R which is too low to be commercial use in a large format device. useful as a radiographic or fluoroscopic It is an aim of the present invention to device. A higher gain device described in provide an x-ray image intensifier tube the same Baiter article exhibited excessive which offers high quality image resolution 35 noise. There is a real question whether a at the output display screen and provides a 100 practical self-supporting MCP plate with substantially full size image at the display uniform gain can be constructed with screen. current technology to sizes beyond five to According to the present invention, an x- * six inches in diameter which is not of ray sensitive image intensifier tube 40 sufficient size to produce an output useful comprises an evacuated tube envelope 105 for radiographic purposes. having an input window comprising at least Another approach involving proximity one of iron, chromium and nickel for design was taken by I.C.P. Millar and his receiving an x-ray image; a substantially flat associates and their results were published in scintillator screen as herein defined 45 1) IEEE Transactions on Electron Devices, adjacent the input window for converting HO Volume ED—18, pages 1101—1108 (1971), the x-ray image into a light pattern image, a and 2) Advances in Electronics and Electron substantially flat photocathode layer Physics, Volume 33A, pages 153—165 parallel to and adjacent the scintillator (1972). screen for emitting photoelectrons in a 50 Millar's approach again involves the use pattern corresponding to the light pattern H5 of a micro-channel plate (MCP). In this image, a substantially flat, phosphor display device, however, the MCP is used purely as screen parallel to and spaced from the an electron multiplication device and not as photocathode layer, there being no tube an x-ray conversion screen. The conversion components present in the space between 55 factor for Millar's tube is reported to be the photocathode layer and the display 120 around 200,000 cd-sec/m2-R, which is above screen and means for applying an or higher than needed for fluoroscopic electrostatic voltage to the display screen purposes, but is far too high for and the photocathode layer so as to create radiographic purposes. However, the an electric field therebetween to accelerate 60 output brightness of Millar's tube also the pattern of photoelectrons toward the 125 exhibits strong dependence on the display screen along substantially parallel, photocathode current density. At around a straight trajectories to impinge upon the photocathode current density of 5xl0~" output display screen; the paths of such amperes/cm or at the equivalent x-ray input parallel straight trajectories being governed 65 dose rate of around 0.6xl0~3R/sec, the solely by the electrostatic voltage applied to 130 3 1,604,3 3 the photocathode layer and the display image to be created at the display screen. screen, the image created at the display Aso, shallowness of the depth of field of the 65 i.
Load more

Recommended publications
  • Review of Night Vision Technology INVITED PAPER K
    OPTO−ELECTRONICS REVIEW 21(2), 153–181 DOI: 10.2478/s11772−013−0089−3 Review of night vision technology INVITED PAPER K. CHRZANOWSKI*1,2 1Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Str., 00–908 Warsaw, Poland 2Inframet, 24 Graniczna Str., Kwirynów, 05–082 Stare Babice, Poland Night vision based on technology of image intensifier tubes is the oldest electro−optical surveillance technology. However, it receives much less attention from international scientific community than thermal imagers or visible/NIR imagers due to se− ries of reasons. This paper presents a review of a modern night vision technology and can help readers to understand sophis− ticated situation on the international night vision market. Keywords: night vision technology, image intensifier tubes. List of abbreviations 1. Introduction ANVIS – aviator night vision imaging system (a term used Humans achieve ability to see at night conditions by using commonly for binocular night vision goggles), several different imaging systems: night vision devices CCD – charge couple device (a technology for constructing (image intensifier systems), thermal imagers, SWIR ima− integrated circuits that use a movement of electrical charge by “shifting” signals between stages within gers, and some more sensitive visible/NIR (CCD/CMOS/ the device one at a time), ICCD/EMCCD) cameras. However, due to historical rea− CCTV – close circuit television (type of visible/NIR cameras sons, night vision technology is usually understood as night used for short range surveillance) vision devices. CMOS – complementary metal−oxide−semiconductor (a tech− Night vision devices (NVDs) are apparently simple sys− nology that uses pairs of p−type and n−type metal tems built from three main blocks: optical objective, image oxide semiconductor field effect transistors for con− intensifier tube, and optical ocular (Fig.
    [Show full text]
  • Microchannel Plate Detectors
    Reprinted from Nuclear Instruments and Methods, Vol. 162, 1979, pages 587 to 601 MICROCHANNEL PLATE DETECTORS JOSEPH LADISLAS WIZA 1. Introduction typical. Originally developed as an amplification element for A microchannel plate (MCP) is an array of 104-107 image intensification devices, MCPs have direct sensitivity miniature electron multipliers oriented parallel to one to charged particles and energetic photons which has another (fig. 1); typical channel diameters are in the range extended their usefulness to such diverse fields as X-ray1) 10-100 µm and have length to diameter ratios (α) between and E.U.V.2) astronomy, e-beam fusion studies3) and of 40 and 100. Channel axes are typically normal to, or biased course, nuclear science, where to date most applications at a small angle (~8°) to the MCP input surface. The have capitalized on the superior MCP time resolution channel matrix is usually fabricated from a lead glass, characteristics4-6). treated in such a way as to optimize the secondary emission The MCP is the result of a fortuitous convergence of characteristics of each channel and to render the channel technologies. The continuous dynode electron multiplier walls semiconducting so as to allow charge replenishment was suggested by Farnsworth7) in 1930. Actual from an external voltage source. Thus each channel can be implementation, however, was delayed until the 1960s considered to be a continuous dynode structure which acts when experimental work by Oschepkov et al.8) from the as its own dynode resistor chain. Parallel electrical contact USSR, Goodrich and Wiley9) at the Bendix Research to each channel is provided by the deposition of a metallic Laboratories in the USA, and Adams and Manley10-11) at coating, usually Nichrome or Inconel, on the front and rear the Mullard Research Laboratories in the U.K.
    [Show full text]
  • European Medical Physics and Engineering Conference
    BULGARIAN SOCIETY OF BIOMEDICAL PHYSICS AND ENGINEERING PPRROOCCEEEEDDIINNGGSS ЕUROPEAN MEDICAL PHYSICS AND ENGINEERING CONFERENCE incorporating XI‐th National Conference of VI‐th European Conference Biomedical Physics and Engineering of Medical Physics 18 – 20 October, 2012 Sofia, Bulgaria Accredited as CPD event for medical physicists by the Endorsed by the European Medical Physics and Engineering Conference, Sofia, October 18‐20, 2012 CO‐ORGANISERS: Nuclear Regulatory Agency Institute of Biophysics and Biomedical Engineering ‐ BAS National Centre of Radiobiology and Radiation Protection Roentgen Foundation ORGANISING COMMITTEE Chairman: Peter Trindev Vice chairman: Athanas Slavchev Secretary: Lubomir Traikov Scientific secretary: Jenia Vassileva Scientific committee members: Alberto Toresin (Italy, EFOMP) Irena Jekova (Bulgaria) Giovanni Bortolan (Italy) Virginia Tsapaki (Greece) Ivo Iliev (Bulgaria) Kristina Bliznakova (Greece) Local organising committee members: Simona Avramova‐Cholakova Ivan Dotsinsky Mikhail Matveev Ana Balabanova Silvia Abarova Borislava Antonova Editorial note The papers in these Proceedings are printed in the content as prepared by the authors. The views expressed remain the responsibility of the authors and not of the Organising Commitee. ISBN 978‐954‐91589‐3‐9 BULGARIAN SOCIETY OF BIOMEDICAL PHYSICS AND ENGINEERING European Medical Physics and Engineering Conference, Sofia, October 18‐20, 2012 TABLE OF CONTENTS PLENARY SESSION Medical Physics Education after the ISCO listing of the profession – Quo Vadis? 8 Slavik Tabakov SIMPOSIUM 1: NEW DEVELOPMENTS IN CANCER TREATMENT Requirements to MRI and MRS data to be applicable for radiation treatment 14 A. Torresin, M.G. Brambilla, P.E. Colombo, M.Minella, A. Monti, A.Moscato REFRESHER COURSES New developments in Radiation Detectors for Medical Imaging 29 I. Kandarakis, G.
    [Show full text]
  • 2002 Military Equipment Export Report)
    Berlin, December 17, 2003 Report by the Government of the Federal Republic of Germany on Its Policy on Exports of Conventional Military Equipment in 2002 (2002 Military Equipment Export Report) Contents S u m m a r y I. The German Control System for Military Equipment Exports 1. The German export control system 2. Application of the “Political Principles” II. German Policy on the Export of Military Equipment in the Multilateral Context 1. Disarmament agreements 2. Arms embargoes 3. Common Foreign and Security Policy (CFSP) in the framework of the EU 4. Framework Agreement concerning Measures to Facilitate the Restructuring and Op- eration of the European Defense Industry 5. Wassenaar Arrangement 6. UN Register of Conventional Arms 7. International discussion on small arms and light weapons III. Licenses for Military Equipment and the Export of War Weapons 1. Licenses for military equipment (war weapons and other military equipment) a) Individual licenses b) Collective export licenses c) Export license denials d) Most important countries of destination e) Individual export licenses broken down by Export List Items . - 2 - f) Export licenses in the years from 1996 to 2002 g) Export licenses for small arms from 1996 to 2002 2. Exports of war weapons a) War weapon exports in reporting year 2002 b) War weapon exports from 1997 to 2002 3. German military equipment exports by international comparison IV. Military Aid V. Criminal Prosecution Statistics and Outline of Preliminary Criminal Proceedings 1. Criminal prosecution statistics 2. Outline of preliminary proceedings under criminal statutes VI. Military Equipment Cooperation VII. Concluding Remarks A n n e x e s Annex 1.
    [Show full text]
  • AN IMAGE INTENSIFIER-SCINTILLATOR DEVICE for DETERMINATION of PROFILES and IMAGES of WEAK BEAMS of IONIZING PARTICLES OR X-Raysf
    NUCLEAR INSTRUMENTS AND METHODS 10 (1961) 348--352; NORTH-HOLLAND PUBLISHING CO. AN IMAGE INTENSIFIER-SCINTILLATOR DEVICE FOR DETERMINATION OF PROFILES AND IMAGES OF WEAK BEAMS OF IONIZING PARTICLES OR X-RAYSf LAWRENCE W. JONES and MARTIN L. PERL Harrison M. Randall Laboratory o/Physics, The University o/Michigan, Ann Arbor, Michigan Received 17 January 1960 An instrument for determining the shape and intensity distri- energy, low intensity, secondary meson and proton beams bution of particle and X-ray beams has been developed using an is given. It is shown that the sensitivity of this instru- image intensifier tube together with a bundle of filaments of ment represents a significant improvement over alternative scintillator. A description of the use of such a device in high techniques. 1. Introduction with a suitable monitor. Weigand 2) has constructed It is possible to construct a monitor for deter- a more elaborate profile monitor consisting of a row mining the intensity profiles of weak beams of high- of scintillation counters connected to an oscil- energy charged particles or X-rays by combining loscope in such a way that the oscilloscope trace filamentary scintillators with an image converter gives beam intensity versus position in one dimen- tube. Such a device, which we will refer to as a sion perpendicular to the beam axis. These methods "Channeled Particle-Image Converter" or CPIC, are inconvenient and of limited resolution. The has been constructed and used by the authors in purpose of the monitor described here is to give a meson beams from the Bevatron. A discussion of two-dimensional presentation of such a beam in- the problems of such monitoring and of existing tensity distribution in weak particle beams.
    [Show full text]
  • Joseph Ladislas Wiza, Microchannel Plate Detectors
    Reprinted from Nuclear Instruments and Methods, Vol. 162, 1979, pages 587 to 601 MICROCHANNEL PLATE DETECTORS JOSEPH LADISLAS WIZA 1. Introduction only by the channel dimensions and spacings; 12 mm diameter channels with 15 mm center-to-center spacings are A microchannel plate (MCP) is an array of 104-107 typical. miniature electron multipliers oriented parallel to one Originally developed as an amplification element for another (fig. 1); typical channel diameters are in the range image intensification devices, MCPs have direct sensitivity 10-100 mm and have length to diameter ratios (a) between to charged particles and energetic photons which has 40 and 100. Channel axes are typically normal to, or biased extended their usefulness to such diverse fields as X-ray1) at a small angle (~8°) to the MCP input surface. The and E.U.V.2) astronomy, e-beam fusion studies3) and of channel matrix is usually fabricated from a lead glass, course, nuclear science, where to date most applications treated in such a way as to optimize the secondary emission have capitalized on the superior MCP time resolution characteristics of each channel and to render the channel characteristics4-6). walls semiconducting so as to allow charge replenishment The MCP is the result of a fortuitous convergence of from an external voltage source. Thus each channel can be technologies. The continuous dynode electron multiplier considered to be a continuous dynode structure which acts was suggested by Farnsworth7) in 1930. Actual as its own dynode resistor chain. Parallel electrical contact implementation, however, was delayed until the 1960s to each channel is provided by the deposition of a metallic when experimental work by Oschepkov et al.8) from the coating, usually Nichrome or Inconel, on the front and rear USSR, Goodrich and Wiley9) at the Bendix Research surfaces of the MCP, which then serve as input and output Laboratories in the USA, and Adams and Manley10-11) at electrodes, respectively.
    [Show full text]
  • Fluoroscopy in Specials: Flat Detector Vs. Image Intensification
    Fluoroscopy in Specials: Flat Detector vs. Image Intensification William R. Geisler M.S. DABR Department of Radiology/Medical Physics Fluoroscopy in Specials: Flat Detector vs. Image Intensification • Acknowledgements: – Perry Juel, SIEMENS – Dean Rindlisbach, PHILIPS – John Rowlands, Univ. Toronto – Phil Rauch, Henry Ford Health System Fluoroscopy in Specials: Digital Flat Detector vs. Image Intensification • Differences and Similarities with image intensification (II) and flat detector (FD) – Brief review II technology – Overview FD technology • Artifacts associated with II and FD Comparison of Image Intensifier and Digital Flat Panel Detector Review II Tube • Vacuum tube • Curvature at input window required to allow focusing of e- and minimize stress from vacuum • Thin (~1 mm) layer of Aluminum at input housing – Attenuates x-rays striking input phosphor • Output phosphor coupled to camera or CCD CsI Input Phosphor/ZnCdS Output Phosphor X-ray Ö Visible Photon Ö e- Ö Visible Photon • X-ray exits patient and interacts with CsI (200 - 400 μm thick for II) • X-ray converted to visible light • light travels along CsI and interacts with photocathode Bushberg 2nd ed fig. 9-3 • photocathode emits e- • 25 – 35 kV accelerates e-sto output phosphor (ZnCdS, < 10 μm) to increase light output Bushberg 2nd ed fig. 9-6 II Gain Factors • Flux Gain (FG) – Increase no. light photons emitted from output phosphor compared to input phosphor; 50 - 100 typical • Minification Gain (MG) – (dia. Input/dia. Output)2 – e.g., 23 cm to 2.5 cm => 85 • Brightness
    [Show full text]
  • A Basic Guide to Night Vision Contents
    A BASIC GUIDE TO NIGHT VISION CONTENTS PAGE 1… NIGHT VISION - PAST PRESENT AND FUTURE 3 2… LIGHT AND DARK 3 3… THE IMAGE INTENSIFIER 4 4… THE GENERATION GAME 4 5… EVALUATING THE PERFORMANCE OF A NIGHT VISION SCOPE 6-7 6… APPLICATIONS 7 7… GLOSSARY & TERMINOLOGY 8-10 8… PRECAUTIONS 10 2 1 NIGHT VISION - PAST, PRESENT AND FUTURE People have many requirements to see at night and powerful illumination systems have been around since the first lighthouse went into service at Eddystone Rock in 1698. However, these systems were simply methods of illumination with the obvious, and sometimes very dangerous drawback, that everyone could see the source of the light. For this reason it became vital that a solution be found for military use - a decisive advantage was to be achieved by gaining the ability to see at night without being seen. In 1887, Heinrich Hertz first discovered photoemission, on which night vision technology is based. In 1905, no lesser person than Albert Einstein theoretically explained the principle - the release of electrons from a solid material due to energy put in to it from radiation and light. The breakthrough came about in 1936 when the first Active Infrared system was developed using a silver photocathode. These systems were very bulky and primitive by todays standards, but at the time they represented a major military advantage. Active Infrared systems continued in use until the late 1970’s in some countries, but NATO forces were phasing them out by the late 1960’s. The main drawback of Active Infrared systems was that to operate they required powerful infrared lamps, which meant the range was restricted by the performance of the lamp.
    [Show full text]
  • Radiation Protection Research and Training Programme 1990-91
    * * Commission of the European Communities radiation protection Radiation protection research and training programme 1990-91 Catalogue of contracts Commission of the European Communities radiation protection Radiation protection research and training programme 1990-91 Catalogue of contracts Edited by: Commission of the European Communities Environment, Consumer Protection and Nuclear Safety Rue de la Loi 200 B-1049 Brussels Directorate-General r ii ./■...!. Science, Research and Development I PAN., i,::? " r c 1991 „ 0 '- - EUR 13387 EN Published by the COMMISSION OF THE EUROPEAN COMMUNITIES Directorate-General Telecommunications, Information Industries and Innovation L-2920 Luxembourg LEGAL NOTICE Neither the Commission of the European Communities nor any person acting on behalf of the Commission is responsible for the use which might be made of the following information Cataloguing data can be found at the end of this publication Luxembourg: Office for Official Publications of the European Communities, 1991 ISBN 92-826-2525-7 Catalogue number: CD-NA-13387-EN-C © ECSC-EEC-EAEC, Brussels • Luxembourg, 1991 Printed in Belgium Preface: The Community Radiation Protection Research and Training Programme was initiated in the framework of the EURATOM TREATY almost 30 years ago. During this time it has undergone major changes in adapting itself to new research needs in relation to the changing demands of radiation protection policies and practices and to new applications of ionizing radiation. The present catalogue of contracts which presents a complete overview of the 1990-1991 Radiation Protection Programme bears witness to this. The Commission now favours multi-partner contracts which allow an even better integration of the work of different institutes into a common goal.
    [Show full text]
  • December 2018
    A Guide To Canada’s Export Control List December 2018 Introduction INTRODUCTION The issuance of export permits under the Export and Import Permits Act (EIPA) is administered by the Trade and Export Controls Bureau of Global Affairs Canada. To assist exporters, the Trade and Export Controls Bureau publishes on its website (www.exportcontrols.gc.ca) important information, such as the Export Controls Handbook, Export Controls Online (EXCOL), Notices to Exporters, Frequently Asked Questions (FAQs), Commodity Codes, and the contact information for the divisions in the Trade and Export Controls Bureau administering export controls for specific items. For information on how to apply for an export permit and additional information on export controls, please refer to our website: www.exportcontrols.gc.ca. For detailed information on export controls, please refer to the Export Controls Handbook: The main reference tool to assist exporters with questions about the administration of Canada’s export controls (except export of logs). The handbook includes how to obtain the necessary permits for the export or transfer of controlled items and how to comply with the requirements of the Export and Import Permits Act and its related regulations. To enquire on the status of an export permit application: Recognized EXCOL users can check the status of an export permit application on-line. Non-recognized users can obtain, from our website (www.exportcontrols.gc.ca), the contact information for the appropriate division responsible for administering the specific control and request a status by providing their export permit application identification (ref ID) number. Export Control List The Regulation establishing Canada’s Export Control List (ECL) can be found at the Department of Justice website at www.laws.justice.gc.ca/eng/regulations.
    [Show full text]
  • Image Intensifier User Guide
    Image Intensifier User Guide This User Manual is intended to provide guidelines for the safe operation of Photek MCP Intensifiers. (Please take particular note of pages 3 and 4). If you require any further details or assistance, please contact Sales or visit: www.photek.co.uk Contents Health and Safety Advice.......................................................................................... 3 High Voltage ..............................................................................................................3 X-Ray Radiation .........................................................................................................3 Storage and Handling ............................................................................................... 3 Operation with an External PSU ................................................................................4 Operation with a Wrap-Around or Flat Pack PSU .....................................................4 Image Intensifiers ..................................................................................................... 5 Introduction ...............................................................................................................5 Mode of Operation ....................................................................................................5 Input Windows ..........................................................................................................5 Spectral Sensitivities of various Photocathodes ........................................................6
    [Show full text]
  • Introduction to Image Intensifier Tubes
    Introduction to Image Intensifier Tubes General The basic principle of image intensification is identical for all different intensifier versions. Fig. 1: Basic principle An image - ultraviolet, visible light, or near infrared - is projected onto the transparent window of the vacuum tube as shown in Fig. 1. The vacuum side of this window carries a sensitive layer called the photocathode. Light radiation causes the emission of electrons from the photocathode into the vacuum which are then accelerated by an applied DC voltage towards a luminescent screen (phosphor screen) situated opposite the photocathode. The screen's phosphor in turn converts high energy electrons back to light (photons), which corresponds to the distribution of the input image radiation but with a flux amplified many times. The terminology "image intensifier" and "image converter" are frequently confused. In par- ticular, image conversion refers to the transfer from an invisible to a visible spectral range, such as image converters used in night vision. On the other hand, image intensifiers which perform as the name suggests often also function as image converters. Image intensifiers are classified in three categories: first, second, and third generation. Each generation has specific advantages and disadvantages. 1 First Generation Image Intensifiers (Intensifier Diodes) Intensifier tubes in this category feature especially high image resolution, a wide dynamic range (the ability to reproduce the ratio between the bright and dark parts of an image), and low noise. They possess moderate gain in the range of some hundreds of Lumens per Lu- men (Im/Im). First generation tubes utilize only a single potential difference to accelerate electrons from the cathode to the anode (screen).
    [Show full text]