E2V Technologies CX1622 Deuterium Thyratron The data to be read in conjunction with the Hydrogen Thyratron Preamble. ABRIDGED DATA Deuterium-filled, flange mounted tetrode thyratron featuring high peak current, high rate of rise of current, low jitter and low anode delay time drift. It has been specifically designed to switch discharge circuits for pulsed lasers and for switching long pulses. It has an internally connected reservoir operated from the cathode heater supply and an internal shield to minimise X-ray emission from the region of the anode. Peak forward anode voltage . . . . . . 35 kV max Peak forward anode current . . . . . . . 5.0 kA max Average anode current . . . . . . . . 0.5 A max Rate of rise of current . . . . . . . . 50 kA/ms max Pulse repetition rate . . . . . . . . 200 pps max GENERAL DATA Electrical Cathode (connected internally mid-point of heater) . . . Heater voltage . . . . . Heater current . . . . . Tube heating time (minimum) to . . . . . . . . . . . . . . . . . . oxide coated . . 6.3 + 5% V . 22 A . . 5.0 min Mechanical Seated height . . . . . 304.8 mm (12.000 inches) max Clearance required below mounting flange . . . . . 44.45 mm (1.750 inches) min Overall diameter (excluding mounting flange) . . . 84.12 mm (3.312 inches) max Net weight . . . . . . . 0.7 kg (1 1/2 pounds) approx Mounting position (see note 1) . . . . . . . . . any Top cap connector (see note 2) . . . . . B.S.448-CT3 Cooling (see note 3) . . . . . . . . . . forced-air MAXIMUM AND MINIMUM RATINGS (Absolute values) Min Max Min Anode (Pulse Laser Service) Peak forward anode voltage (see note 4) . . . . . Peak inverse anode voltage (see note 5) . . . . . Peak forward anode current . Average anode current . . Rate of rise of anode current (see notes 6 and 7) . . . Pulse repetition rate . . . Max Anode (Pulse Modulator Service) . . . . – 35 kV . . . . – . . . . – . . . . – 25 5.0 0.25 kV kA A . . . . – . . . . – 50 50 kA/ms pps Peak forward anode voltage (see note 4) . . . . . Peak inverse anode voltage (see note 5) . . . . . Peak forward anode current . Average anode current . . Rate of rise of anode current (see notes 6 and 7) . . . Pulse repetition rate . . . . . . . – 35 kV . . . . – . . . . – . . . . – 25 5.0 0.5 kV kA A . . . . – . . . . – 5.0 kA/ms 200 pps E2V Technologies Limited, Waterhouse Lane, Chelmsford, Essex CM1 2QU England Telephone: +44 (0)1245 493493 Facsimile: +44 (0)1245 492492 e-mail: [email protected] Internet: www.e2vtechnologies.com Holding Company: E2V Holdings Limited E2V Technologies Inc. 4 Westchester Plaza, PO Box 1482, Elmsford, NY10523-1482 USA Telephone: (914) 592-6050 Facsimile: (914) 592-5148 e-mail: [email protected] #E2V Technologies Limited 2002 A1A-CX1622 Issue 5, October 2002 527/5640 MAXIMUM AND MINIMUM RATINGS NOTES (Continued) Min Max Grid 2 (See note 7) Unloaded grid 2 drive pulse (see note 8) . . . . Grid 2 pulse duration . . Rate of rise of grid 2 pulse (see note 6) . . . . Grid 2 pulse delay . . . Peak inverse grid 2 voltage Loaded grid 2 bias voltage Forward impedance of grid 2 drive circuit . . voltage . . . . 600 . . . . . 0.5 . . . . . . . . . . . . . . . . 2000 – V ms . 1.0 – kV/ms . 0 3.0 ms . – 450 V 750 7200 V . . . . 50 200 O Grid 1 – Pulsed (See note 7) Peak grid 1 drive current Unloaded grid 1 drive pulse (see note 8) . . . . Grid 1 pulse duration . . Rate of rise of grid 1 pulse (see note 6) . . . . Peak inverse grid 1 voltage Loaded grid 1 bias voltage . . . . . 0.3 voltage . . . . 300 . . . . . 1.0 1.0 2000 – A V ms . . . . . 1.0 – kV/ms . . . . . – 450 V . . . . . . . . see note 10 Grid 1 – DC Primed (See note 9) DC grid 1 unloaded priming voltage . DC grid 1 priming current . . . . 75 50 150 100 V mA 1. The tube must be fitted using its mounting flange. 2. A large area anode connector, E2V Technologies type MA360A, is recommended. 3. Cooling of the anode stem is necessary under conditions of high voltage and high anode dissipation in order to avoid damage to the tube. 4. The maximum permissible peak forward voltage for instantaneous starting is 25 kV and there must be no overshoot. 5. The peak inverse voltage must not exceed 10 kV for the first 25 ms after the anode pulse. Amplitude and rate of rise of inverse voltage contribute greatly to tube dissipation and electrode damage; if these are not minimised in the circuit, tube life will be shortened considerably. The aim should be for an inverse voltage of 3 – 5 kV peak with a rise time of 0.5 ms. 6. This rate of rise refers to that part of the leading edge of the pulse between 10% and 90% of the pulse amplitude. 7. For applications requiring the highest rate of rise of anode current, grid 1 should be pulse driven. Maximum grid drives should be used, the rate of rise of grid 2 trigger pulse should be as high as possible and the grid 2 pulse delay should be 0.2 ms min. For less severe applications, good results can be obtained by driving both grids from a single pulse using the circuit shown in Fig. 1. 5502A 1.0 kV 100 O GRID 2 Cathode 0.5 ms Heater voltage . . . . . . . . . Tube heating time . . . . . . . . 6.3 + 5% 5.0 – V min 0.1 mF 1.0 kO GRID 1 Environmental Ambient temperature . . . . . . 750 Altitude . . . . . . . . . . . – – +90 3 10 000 8C km ft Min Typical Max CX1622, page 2 CATHODE Fig. 1 Circuit for single pulse drive CHARACTERISTICS Critical DC anode voltage for conduction (see note 11) . Anode delay time (see notes 11 and 12) . . Anode delay time drift (see notes 11 and 13) . . Time jitter (see note 11) . . Heater current (at 6.3 V) . 10 kO . . – 0.5 2.0 kV . . – 0.15 0.25 ms . . – . . – . 18 20 1.0 22 50 5.0 25 ns ns A 8. Measured with respect to cathode. When grid 1 is pulse driven, the last 0.25 ms of the top of the grid 1 pulse must overlap the corresponding first 0.25 ms of the top of the delayed grid 2 pulse. 9. When DC priming is used on grid 1, a negative bias of 100 V to 200 V must be applied to grid 2 to ensure anode voltage hold-off. 10. DC negative bias voltages must not be applied to grid 1. The potential of grid 1 may vary between 710 V and +5 V with respect to cathode potential during the period between the completion of recovery and the commencement of the succeeding grid pulse. 11. Typical figures are obtained on test using conditions of minimum grid drive. Improved performance can be expected by increasing grid drive. 12. The time interval between the instant at which the rising unloaded grid 2 pulse reaches 25% of its pulse amplitude and the instant when anode conduction takes place. 13. The drift in delay time over a period from 10 seconds to 10 minutes after reaching full voltage. #E2V Technologies OUTLINE (All dimensions without limits are nominal) 1K 4900B L 1B A Ref Millimetres Inches A B C D E F G H J K L 304.8 max 84.12 max 215.9 + 13.0 111.1 95.25 1.6 6.5 381.0 6.35 14.38 + 0.18 12.70 min 12.000 max 3.312 max 8.500 + 0.512 4.375 3.750 0.063 0.256 15.000 0.250 0.566 + 0.007 0.500 min Inch dimensions have been derived from millimetres. Outline Notes C 1. The recommended hole in the mounting plate is 76 mm (3.0 inches) diameter. 2. A minimum clearance of 44.45 mm (1.750 inches) must be allowed below the mounting surface. 3. The mounting flange is the cathode connection, and this is connected internally to the mid-point of the heater. SEE NOTE 3 F SEE NOTE 1 SEE NOTE 2 GRID 1 LEAD (GREEN) H LONG, TAG TO SUIT 1J 3 HOLES 1G EQUISPACED ON E PCD GRID 2 LEAD (WHITE) H LONG, TAG TO SUIT 1J 1D CATHODE HEATER LEADS (YELLOW) H LONG, TAGS TO SUIT 1J #E2V Technologies CX1622, page 3 HEALTH AND SAFETY HAZARDS E2V Technologies hydrogen thyratrons are safe to handle and operate, provided that the relevant precautions stated herein are observed. E2V Technologies does not accept responsibility for damage or injury resulting from the use of electronic devices it produces. Equipment manufacturers and users must ensure that adequate precautions are taken. Appropriate warning labels and notices must be provided on equipments incorporating E2V Technologies devices and in operating manuals. High Voltage Equipment must be designed so that personnel cannot come into contact with high voltage circuits. All high voltage circuits and terminals must be enclosed and fail-safe interlock switches must be fitted to disconnect the primary power supply and discharge all high voltage capacitors and other stored charges before allowing access. Interlock switches must not be bypassed to allow operation with access doors open. X-Ray Radiation All high voltage devices produce X-rays during operation and may require shielding. The X-ray radiation from hydrogen thyratrons is usually reduced to a safe level by enclosing the equipment or shielding the thyratron with at least 1.6 mm ( 1/16 inch) thick steel panels. Users and equipment manufacturers must check the radiation level under their maximum operating conditions. Whilst E2V Technologies has taken care to ensure the accuracy of the information contained herein it accepts no responsibility for the consequences of any use thereof and also reserves the right to change the specification of goods without notice. E2V Technologies accepts no liability beyond that set out in its standard conditions of sale in respect of infringement of third party patents arising from the use of tubes or other devices in accordance with information contained herein. CX1622, page 4 Printed in England #E2V Technologies