National Institutes of Health, Division of Procurement, AB-A 6120 Executive Blvd., Room 898, Rockville, MD 20892

66 -- ELECTRON MICROSCOPE SOL 263-95-B(BN)-0052 DUE 083195 POC Foteni T. Tiffany, Contract Specialist 301-402-3079. 17. The National Institutes of Health, National Eye Institute, requires a Transmission Electron Microscope and accessories for their laboratory in Bethesda, Maryland. The microscope will be used to conduct research which involves the preparation and analysis of animal and human tissues that are either normal or affected by a wide range of disorders, particularly immunology diseases. The microscope shall have that following minimum required specifications: 1) ACCELERATING VOLTAGE: The accelerating voltage shall be variable from 100 kV to 40 kV in increments of choice down to 25 volt steps. 2) COOL BEAM WEHNELT: Shall have conical wehnelt to allow adjustment of filament tip to a specific distance from aperture of wehnelt, for maximum coherence of electrons, uniform beam density and use of very low beam currents (4-5 microamps), thus optimizing image quality and greatly extending filament life. Filaments shall be pre-centered. Single crystal LaB6 shall be supplied as a standard electron source and easily interchanged with a hairpin filament. 3) AUTO-START AND FILAMENT SATURATION: Built in timer shall allow for pre-selected start of microscope. Filament saturated automatically. 4) MULTIPLE OBJECTIVE LENS POLE PIECES: The Government will choose any single pole piece to be furnished with the microscope, among the following (all shall be field exchangeable): a) High-tilt, wide- field/high contrast: Focal length of 5.0 mm, +60 degrees tilt, guaranteed resolution of 0.2 nm by lattice test and 0.45 nm point to point. Magnification range of 50X through 500,000X. By repositioning the O.L. aperture assembly, to reside in the back focal plane, it shall be possible to observe a full field of view using a 20u aperture. Tilt of +25 degrees. This configuration shall provide the highest possible contrast. b) High contrast: Shall have a focal length of 3.9 mm, +20 degrees of tilt, and a guaranteed resolution of 0.2 nm by lattice test and 0.4 nm point to point. Magnification range shall be 50X through 600,000X. c) High resolution: Shall have a focal length of 2.5 mm, +25 degrees of tilt, and a guaranteed resolution of 0.14 nm by lattice test and 0.3 nm point to point. Shall have a magnification range of 50X through 1,000,000X. 5) LOW MAGNIFICATION MODE: Fully focussable, photographable images shall be provided from at least 50X through 1000X in twelve or more steps. 6) ELECTRON DIFFRACTION: Both selected areas (SAD) and high dispersion (HD) diffraction shall be available - free of rotation - on the standard instrument. This capability may vary slightly with each pole piece: a) SAD = 200 to 5,000 mm, 15 steps, HD = 4 to 80 m, 14 steps. b) SAD = 150 to 3,500 mm, 15 steps, HD = 4 to 80 m, 14 steps. c) SAD = 100 to 2,500 mm, 15 steps, HD = 4 to 80 m, 14 steps. 7) ROTATION-FREE IMAGING: Shall be provided through the entire magnification range. There shall be no shift in the center of the field of view. 8) DARK FIELD IMAGING: Continuous beam tilt to +6 degrees shall be provided in both X and Y directions with instant changeover between bright field and dark field modes. Five (5) condition memories shall be available. 9) SPECIMEN HOLDERS: Standard specimen holder shall provide approximately 8 mm of travel, along the tilt axis, enabling two grids to be loaded in simple quick-load, snap-lock retainer mechanisms. A motor drive shall provide rapid grid selection. A multiple- specimen holder shall be furnished to load at least five (5) specimens simultaneously. Exchange shall be made by positive click-stop action. A rotational specimen holder shall be furnished to provide 360 degrees rotation in the tilted plane. Tilt range as per pole piece above. 10) FIELD POSITION MEMORY: Shall be supplied. It shall display on CRT - label, store and recall on command - X and Y coordinates for up to ten (10) selected areas of interest. 11) MEMORY FUNCTION: Shall be provided. It shall store up to twenty (20) combinations of lens, deflector and stigmator conditions for illumination and imaging systems. It shall permit instantaneous recall as desired. 12) IMAGE ORIENTATION SYSTEM: Shall be provided to rotate the image up to +90 degrees. Increments of 15 degrees shall be possible. After setting desired orientation, magnification shall be variable. A range of approximately 2,000X to 50,000X (depending on O.L. pole piece (above) in use) shall be possible. 13) ON- SCREEN MEASUREMENT FUNCTION: Shall be provided to allow measurements of a TEM image or diffraction pattern, on line, while observing the image. Capability shall include length of lines and curves, ratio between two lengths or d-spacing values, area and perimeter of features, angle between two lines or two lattice planes. 14) FILE SYSTEM: Shall be available to store in memory the personal data of up to ten (10) operators. Data shall include operator code, film number of last photograph taken, all camera conditions including film sensitivity, direction, frequency and amplitude settings of image wobbler, through-focus conditions and user-programmable magnification, low magnification and camera length steps. Shall recall all, automatically and/or manually entered data, from the fifty most recently exposed films. 15) PHOTOGRAPHIC SYSTEM: Shall provide for loading fifty (50) 3.25 inch X 4 inch (8.26cm X 10.2cm) sheet films in a single load. Two loading boxes and two receiving boxes shall be provided. Data recorded on film shall include 4-digit number, two characters for operator I.D., magnification/camera length with micron bar, kV and up to 18 characters of text, entered through a standard keyboard, supplied with the microscope. 16) VACUUM SYSTEM: Shall consist of two high speed (420 1/sec) diffusion pumps (DPs). The DPs shall be arranged in a cascade fashion. During normal operation, the lower DP shall pump the viewing and camera chambers while backing the upper DP continuously. This design shall provide a much higher backing vacuum to the upper DP and, consequently, a cleaner, higher column vacuum. After rough pumping the camera chamber, following film exchange, the camera shall be evacuated to high vacuum by a DP before the camera airlock is opened to the electron optical column, thus eliminating degradation of vacuum in the column following film exchange. Routine column vacuum shall be in the 10/-7 Torr range. A large buffer tank shall be included to support the upper DP during the film exchange configuration. A low-maintenance DP/DP system is considered best for most biological specimens, as it is extremely efficient in removing water vapor. Turbo pumps increase the possibility of vibration in the image and catastrophic failure, while ion pumps degenerate over time. Neither turbo or ion pumping is desired. The Contractor shall be required to furnish, deliver, install and provide training in accordance with salient characteristics/specifications specified in the solicitation. All requests for solicitation shall be in writing. All responsible sources may submit a bid which shall be considered by the agency. (0193)

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