1988 Ed.]
Import and Export (Strategic Commodities) Regulations
[CAP. 60
G83
[Subsidiary]
IL1556
IL1558
Optical elements and elements for optical tubes, as follows-
(a) Non-flexible fused fibre-optic plates or bundles, having all of the following characteristics:
(1) A fibre pitch (centre-to-centre spacing) of less than 10 micrometres;
(2) A light-absorbing medium surrounding each fibre, or interstitially placed between fibres;
(3) A diameter greater than 13 mm (1 inch);
(b) Microchannel-plates for electron image amplification having both of the following characteristics:
(1) 15 000 or more hollow tubes per plate; and
(2) Hole pitch (centre-to-centre spacing) of less than 25 micrometres;
(c) Semi-transparent photocathodes incorporating epitaxially grown layers of compound semiconductors, such as gallium arsenide;
(For associated starting materials see Item IL1757.)
(d) Diffractive type optical elements specially designed for display screens with any of the following characteristics:
(1) A transmission of more than 10 per cent outside the reflection band and a reflection of more than 75 per cent inside the reflection band, which has less than 15 nanometres bandwidth and is matched to the frequency of the display light source;
(2) A rear projection screen Brightness gain of more than 10 times the gain of a Lambertian scatterer with an equivalent area, and less than 10 per cent variation in brightness across the exit aperture;
(3) Specially designed for use in helmet-mounted displays.
Electronic vacuum tubes (valves) and cathodes, as follows, and other components specially designed for those tubes-
(a) Tubes in which space charge control is utilized as the primary functional parameter, including but not limited to triodes and tetrodes, as follows:
(1) Tubes rated for continuous wave operation having either of the following characteristics:
(i) Above 4 GHz at maximum rated anode dissipation; or
(ii) Within the frequency range 0.3 to 4 GHz and for which, under any condition of cooling, the product of the maximum rated anode dissipation (expressed in watts) and the square of the maximum frequency (expressed in Gigahertz) at the maximum rated anode dissipation is greater than 10, except for tubes specially designed for television transmitters operating in the frequency range of 0.47 to 0.96 GHz and rated for operation without a grid current, for which the product of the rated anode dissipation (expressed in watts) and the square of the maximum frequency (expressed in Gigahertz) may reach 2 × 104;
(2) Tubes rated only for pulse operation having either of the following characteristics:
(i) Above 1 GHz, with maximum peak pulse output power greater than 45 kW; or
(ii) Between 0.3 and 1 GHz and for which, under any condition of cooling, the product of the peak pulse output power (expressed in watts) and the square of the maximum frequency (expressed in Gigahertz) is greater than 4.5 × 104;
(3) Tubes specially designed for use as pulse modulators for radar or similar applications, having a peak anode voltage rating of 100 kV or more, or rated for a peak pulse power of 20 MW or more (see also Item IL1514):
(b) Tubes which utilize interaction between a beam of electrons and microwave elements and in which the electrons travel in a direction perpendicular to the applied magnetic field, including but not limited to magnetrons, crossed-field amplifier tubes and crossed-field oscillator tubes, except: