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Press releases and comments on new equipment
Micron, 1980, Vol.: U , pp. 207-210. Pergamon Press Ltd. Printed in Great Britain
PRESS RELEASES AND COMMENTS ON The aim of this section is to introduce readers of Micron to new equipment which may be of interest to them. No attempt is made to compare such equipment which must necessarily depend upon a variety of factors including the requirements of individual users. Any specifications quoted are those given by the manufacturers. For reasons of space, only a limited number of items can be included in any one issue.
NEW 600kV H I G H RESOLUTION ELECTRON MICROSCOPE A 600kV electron microscope, designed to provide image resolution to the atomic level, was opened by Sir James Menter, FRS on 18 May 1979. It has been financed by the Science Research Council and the University of Cambridge. Designed and constructed as a joint project between the Engineering and Physics Departments, it is situated in the Old Cavendish Laboratory in a room originally used by James Clerk Maxwell in 1874 for precision electrical and magnetic experiments. It has been built to very high standards of mechanical precision and electrical stability. Initial tests of performance suggest that it will be as powerful as any other electron microscope in the world and superior to any microscope which will be available in the U.K. in the foreseeable future. The main role of the new microscope is to examine a wide variety of crystalline and amorphous metals and semi-conductors, and macromolecules, from a number of scientific disciplines, at sufficiently high magnification and resolution to make visible detail on the atomic scale, such as defects in crystals which cannot be imaged directly in any other way. If problems of radiation damage can be reduced, the atomic structure of organic, and perhaps even biological, molecules could be displayed. Planning of the high resolution electron microscope (Fig. 1) began some 8 years ago following an invitation from the Science Research Council to submit a joint project on electron optical instrumentation based on the extensive experience of members of the Cavendish Laboratory and the Engineering Department. It has been financed mainly by grants from the Science Research Council totalling some £650,000, with support from Cambridge University in money and manpower that can be estimated roughly as £400,000 over the 8 years of the project. Smaller initial contributions came from the * Three copies of the appropriate Press Release giving a summary of the main features of the equipment together with details of the cost, and ~ne black and white gloss print should be sent to Professor R. W. Horne at the address given on the inside of the front cover. t Present Address: Imperial College of Science and Technology, Department of Metallurgy and Materials Science, London, U.K. 207
NEW
EQUIPMENT*
Department of Trade and Industry and AEI Scientific Instruments (now Kratos) through the supply of specific items from AEI. The total investment has been well over £1m. To monitor the progress of the project the Materials Science and Technology Committee of SRC appointed a Management Committee, now chaired by Dr. D. W. Pashley, FRS, the head of Tube Investment Research Laboratories.t Although this is not the first high voltage electron microscope to be designed for high resolution, it has several unique features which make it the most flexible and versatile. The electron gun employs a lanthanum hexaboride cathode which gives such a high brightness that images can be observed on the viewing screen even at a direct magnification of 500,000 times, making focusing and correction of image astigmatism much easier. The microscope, which with the electron accelerator weighs some 7 tonnes, is supported on a three-point suspension system to reduce the effect of site vibrations. The high voltage generator, supplied by the firm of Emile Haefely of Basel to a high specification (Fig. 2) has been further stabilized to better than one part in a million by electronic means designed and constructed locally. The basis of the microscope proper consists of the column of electron lenses of the EM-7 microscope developed by AEI. That microscope was partly based on the original 750kV microscope built in the Cavendish Laboratory in the 1960s. The most important lens, the high-power objective, has been modified to improve its imaging performance. Circuits of the extra high stability required for the lens current supplies have again been made on site. It is essential to maintain the specimen in conditions of the greatest mechanical stability during photography, yet it must be possible to move it laterally and often to tilt it during observation. A specimen stage to meet these requirements was produced by Mr. J. H. Lucas (of Rickling, Essex). At present electron images are recorded in the usual way on photographic film, but an image display system of TV type, designed and constructed here, is about to be installed. The microscope has been designed and built through the skills of many members of both Departments, staff, assistants, and technicians. These include for the Cavendish Laboratory: Dr. V. E. Cosslett, FRS, Principal Investigator for the Department of Physics, Dr. P. W. Hawkes, Dr. W. O. Saxton, Dr. D. J. Smith, Mr. R. A. Camps, Mr. D. Rose, and Mr. R. H. Pryor; for the Engineering Department: Dr. W. C. Nixon, Principal Investigator for the Department of Engineering, Dr. H. Ahmed, Dr. C. J. D. Catto, Dr. J. R. A. Cleaver, the late Professor Ross, Dr. K. C. A. Smith, Mr. A. E. Timbs, and Mr. P. W. Turner; and a number of University technical assistants in both departments including Mr. L. Coe, Mr. P. Everatt, Mr. R. Hume, Mr. A. D. King, Mr. N. Leavis and Mr. J. Sales. Dr. M. E. Haine has been closely associated with the project, initially for AEI and latterly for the SRC Management Committee. Valuable
208
Press Releases and Comments on New Equipment
Fig. 1. The photograph shows the main part of the 600kV high resolution electron microscope column together with two control consoles. Part of the three-point suspension system can be seen extending from the walls to the central frame which supports the large column.
Press Releases and Comments on New Equipment
Fig. 2. The 600kV high voltage generator is mounted above the electron microscope column. The photograph also shows the gap separating the platform on which the EHT generator is mounted independently from the main floor area. (Photographs reproduced by kind permission of the Cavendish Laboratory and University Engineering Department, Cambridge.)
209
210
Press Releases and Commen~s on New Equipment
advice was given by Dr. W. D. Riecke (Germany), particularly on the high-power objective lens. Preliminary investigations, made by Dr. D. J. Smith in collaboration with specialists in Cambridge and elsewhere, have already demonstrated the potentialities of the new microscope in a range of problems of considerable scientific and technological importance. These include the structure of catalysts and small metal particles, studies of radiation-sensitive molecular crystals, and the observation of various complex inorganic oxides. Under carefully chosen operating conditions, image detail of atomic dimensions can be directly interpreted. It is notable that this pioneer development in electron microscopy was initiated and carried out by University scientists and engineers. In this country, as in France and
Germany (though not in Japan or the United States), almost all the new and sophisticated electron beam instruments have originated in academic laboratories, before being taken up by ind ustry. Cambridge alone has produced in recent years the scanning electron microscope and electron beam micro-fabrication (from the Engineering Department), and the electron probe micro-analyser and high voltage electron microscope (from the Cavendish Laboratory). Although no large market is in prospect for an instrument as costly as the HREM, interest has been expressed by several laboratories abroad. Further information is available from the Cavendish Laboratory and University Engineering Department, University of Cambridge, Cambridge, U.K.
PRESS RELEASES AND COMMENTS ON The aim of this section is to introduce readers of Micron to new equipment which may be of interest to them. No attempt is made to compare such equipment which must necessarily depend upon a variety of factors including the requirements of individual users. Any specifications quoted are those given by the manufacturers. For reasons of space, only a limited number of items can be included in any one issue.
NEW 600kV H I G H RESOLUTION ELECTRON MICROSCOPE A 600kV electron microscope, designed to provide image resolution to the atomic level, was opened by Sir James Menter, FRS on 18 May 1979. It has been financed by the Science Research Council and the University of Cambridge. Designed and constructed as a joint project between the Engineering and Physics Departments, it is situated in the Old Cavendish Laboratory in a room originally used by James Clerk Maxwell in 1874 for precision electrical and magnetic experiments. It has been built to very high standards of mechanical precision and electrical stability. Initial tests of performance suggest that it will be as powerful as any other electron microscope in the world and superior to any microscope which will be available in the U.K. in the foreseeable future. The main role of the new microscope is to examine a wide variety of crystalline and amorphous metals and semi-conductors, and macromolecules, from a number of scientific disciplines, at sufficiently high magnification and resolution to make visible detail on the atomic scale, such as defects in crystals which cannot be imaged directly in any other way. If problems of radiation damage can be reduced, the atomic structure of organic, and perhaps even biological, molecules could be displayed. Planning of the high resolution electron microscope (Fig. 1) began some 8 years ago following an invitation from the Science Research Council to submit a joint project on electron optical instrumentation based on the extensive experience of members of the Cavendish Laboratory and the Engineering Department. It has been financed mainly by grants from the Science Research Council totalling some £650,000, with support from Cambridge University in money and manpower that can be estimated roughly as £400,000 over the 8 years of the project. Smaller initial contributions came from the * Three copies of the appropriate Press Release giving a summary of the main features of the equipment together with details of the cost, and ~ne black and white gloss print should be sent to Professor R. W. Horne at the address given on the inside of the front cover. t Present Address: Imperial College of Science and Technology, Department of Metallurgy and Materials Science, London, U.K. 207
NEW
EQUIPMENT*
Department of Trade and Industry and AEI Scientific Instruments (now Kratos) through the supply of specific items from AEI. The total investment has been well over £1m. To monitor the progress of the project the Materials Science and Technology Committee of SRC appointed a Management Committee, now chaired by Dr. D. W. Pashley, FRS, the head of Tube Investment Research Laboratories.t Although this is not the first high voltage electron microscope to be designed for high resolution, it has several unique features which make it the most flexible and versatile. The electron gun employs a lanthanum hexaboride cathode which gives such a high brightness that images can be observed on the viewing screen even at a direct magnification of 500,000 times, making focusing and correction of image astigmatism much easier. The microscope, which with the electron accelerator weighs some 7 tonnes, is supported on a three-point suspension system to reduce the effect of site vibrations. The high voltage generator, supplied by the firm of Emile Haefely of Basel to a high specification (Fig. 2) has been further stabilized to better than one part in a million by electronic means designed and constructed locally. The basis of the microscope proper consists of the column of electron lenses of the EM-7 microscope developed by AEI. That microscope was partly based on the original 750kV microscope built in the Cavendish Laboratory in the 1960s. The most important lens, the high-power objective, has been modified to improve its imaging performance. Circuits of the extra high stability required for the lens current supplies have again been made on site. It is essential to maintain the specimen in conditions of the greatest mechanical stability during photography, yet it must be possible to move it laterally and often to tilt it during observation. A specimen stage to meet these requirements was produced by Mr. J. H. Lucas (of Rickling, Essex). At present electron images are recorded in the usual way on photographic film, but an image display system of TV type, designed and constructed here, is about to be installed. The microscope has been designed and built through the skills of many members of both Departments, staff, assistants, and technicians. These include for the Cavendish Laboratory: Dr. V. E. Cosslett, FRS, Principal Investigator for the Department of Physics, Dr. P. W. Hawkes, Dr. W. O. Saxton, Dr. D. J. Smith, Mr. R. A. Camps, Mr. D. Rose, and Mr. R. H. Pryor; for the Engineering Department: Dr. W. C. Nixon, Principal Investigator for the Department of Engineering, Dr. H. Ahmed, Dr. C. J. D. Catto, Dr. J. R. A. Cleaver, the late Professor Ross, Dr. K. C. A. Smith, Mr. A. E. Timbs, and Mr. P. W. Turner; and a number of University technical assistants in both departments including Mr. L. Coe, Mr. P. Everatt, Mr. R. Hume, Mr. A. D. King, Mr. N. Leavis and Mr. J. Sales. Dr. M. E. Haine has been closely associated with the project, initially for AEI and latterly for the SRC Management Committee. Valuable
208
Press Releases and Comments on New Equipment
Fig. 1. The photograph shows the main part of the 600kV high resolution electron microscope column together with two control consoles. Part of the three-point suspension system can be seen extending from the walls to the central frame which supports the large column.
Press Releases and Comments on New Equipment
Fig. 2. The 600kV high voltage generator is mounted above the electron microscope column. The photograph also shows the gap separating the platform on which the EHT generator is mounted independently from the main floor area. (Photographs reproduced by kind permission of the Cavendish Laboratory and University Engineering Department, Cambridge.)
209
210
Press Releases and Commen~s on New Equipment
advice was given by Dr. W. D. Riecke (Germany), particularly on the high-power objective lens. Preliminary investigations, made by Dr. D. J. Smith in collaboration with specialists in Cambridge and elsewhere, have already demonstrated the potentialities of the new microscope in a range of problems of considerable scientific and technological importance. These include the structure of catalysts and small metal particles, studies of radiation-sensitive molecular crystals, and the observation of various complex inorganic oxides. Under carefully chosen operating conditions, image detail of atomic dimensions can be directly interpreted. It is notable that this pioneer development in electron microscopy was initiated and carried out by University scientists and engineers. In this country, as in France and
Germany (though not in Japan or the United States), almost all the new and sophisticated electron beam instruments have originated in academic laboratories, before being taken up by ind ustry. Cambridge alone has produced in recent years the scanning electron microscope and electron beam micro-fabrication (from the Engineering Department), and the electron probe micro-analyser and high voltage electron microscope (from the Cavendish Laboratory). Although no large market is in prospect for an instrument as costly as the HREM, interest has been expressed by several laboratories abroad. Further information is available from the Cavendish Laboratory and University Engineering Department, University of Cambridge, Cambridge, U.K.