E2V Technologies CX1157 (Service Type CV6241) Hydrogen-Filled Ceramic Thyratron The data to be read in conjunction with the Hydrogen Thyratron Preamble. (Absolute values) ABRIDGED DATA Hydrogen-filled tetrode thyratron with ceramic envelope, featuring low jitter and low anode delay time drift. Suitable for use at high pulse repetition rates and in applications requiring ruggedness and compactness. A hydrogen reservoir operating from the heater supply is incorporated. Peak forward anode voltage . . . . . . 20 kV max Peak anode current . . . . . . . . 350 A max Average anode current . . . . . . . 500 mA max Anode heating factor . . . . . . 7.0 x 109 VApps max Peak output power . . . . . . . . . 3.5 MW max GENERAL Min Max Anode Peak forward anode voltage (see note 3) . . . . . Peak inverse anode voltage (see note 4) . . . . . Peak anode current . . . Average anode current . . Rate of rise of anode current (see notes 5 and 6) . . . Anode heating factor . . . . . . . – 20 kV . . . . – . . . . – . . . . – 20 350 500 kV A mA . . . . – . . . . – 2500 A/ms 7.0 x 109 VApps Grid 2 Electrical Cathode (connected internally to one end of heater) . . . . Cathode heater voltage . . . Cathode heater current . . . Reservoir heater voltage (see note Reservoir heater current . . . Tube heating time (minimum) . . . . 1) . . . . . . . . . . . oxide coated V 6.3 + 7 1/2% . . 7.5 A 6.3 + 7 1/2% V . . 1.5 A . . 3.0 min Mechanical Seated height . . . . Clearance required below mounting flange . . . Overall diameter (mounting flange) . . Net weight . . . . . Mounting position (see note Tube connections . . . PULSE MODULATOR SERVICE MAXIMUM AND MINIMUM RATINGS . . 76.2 mm (3.000 inches) max . . 31.75 mm (1.250 inches) min . 57.15 mm (2.250 inches) nom . . . 284 g (10 ounces) approx 2) . . . . . . . . . any . . . . . . . . see outline Cooling . . . . . . . . natural, forced-air or liquid Where natural cooling is insufficient to maintain the envelope temperatures below the specified rated values, cooling by forced-air, or by oil or coolant immersion may be used. The temperature of the anode terminal and the base, measured at the points indicated on the outline drawing, must not exceed the values specified below. Anode terminal . . . . . . . . . . 250 8C max Base . . . . . . . . . . . . . 220 8C max Unloaded grid 2 drive pulse voltage (see note 7) . . . . . . . Grid 2 pulse duration . . . . . Rate of rise of grid 2 pulse (see note Grid 2 pulse delay . . . . . . Peak inverse grid 2 voltage . . . Loaded grid 2 bias voltage (see note 8) . . . . . . . Forward impedance of grid 2 drive circuit . . . . . . . 6) . . 200 . 1.0 . 1.0 . 0.5 . – 750 V – ms – kV/ms 3.0 ms 200 V 750 7200 V 100 1000 O 150 150 V mA . Grid 1 – DC Primed (See note 9) DC grid 1 unloaded priming voltage . DC grid 1 priming current . . . . 75 50 Grid 1 – Pulsed (See note 10) Unloaded grid 1 drive pulse voltage (see note 7) . . . . . . . Grid 1 pulse duration . . . . . Rate of rise of grid 1 pulse (see note Peak inverse grid 1 voltage . . . Loaded grid 1 bias voltage . . . Peak grid 1 drive current . . . . . . 6) . . . 300 . 2.0 . 1.0 . – . . . . 0.15 750 V – ms – kV/ms 200 V see note 11 0.5 A Cathode Heater voltage . . . . . . . . . 6.3 + 7 1/2% Heating time . . . . . . . . . . 3.0 – V min Reservoir Heater voltage (see note 1) . . . . . 6.3 + 7 1/2% Heating time . . . . . . . . . . 3.0 – V min Environmental (See note 12) Ambient temperature . . . . . 755 Altitude . . . . . . . . . . . – – +130 3 10 000 8C km ft 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: Redwood 2002 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-CX1157 Issue 3, September 2002 527/5626 CHARACTERISTICS NOTES Min Typical Max Critical DC anode voltage for conduction (see note 10) . Anode delay time (see notes 10 and 13) . . Anode delay time drift (see notes 10 and 14) . . Time jitter (see note 10) . . Recovery time . . . . . Heater and reservoir current (at 6.3 V) . . . . . . . . – 0.2 0.3 kV . . – 0.15 0.25 ms . . – 20 50 ns . . – 1.0 5.0 ns . . . see note 15 and curves . . 7.5 9.0 10.5 A SINGLE-SHOT OR CROWBAR SERVICE In applications requiring a very rapid rate of rise of anode current, the CX1157 geometry allows it to be mounted in a coaxial structure in order to minimise the total circuit inductance. Operation of the tube under the following ratings results in short anode delay times and very low time jitter. MAXIMUM AND MINIMUM RATINGS (Absolute values) Min Typical Max Anode Peak forward anode voltage (see note 16) . . . . . . . – Peak anode current (see note 17) . . . . . . . – Average anode current . . . . – – 20 kV – – 3000 300 A mA Grid 2 Unloaded grid 2 drive pulse voltage . . . . . . Grid 2 pulse duration . . Rate of rise of grid 2 pulse (unloaded) . . . . Loaded grid 2 bias voltage Forward impedance of grid 2 drive circuit . . . . . 0.5 . . . 0.25 . . 10 . 750 1.0 – 2.0 5.0 kV ms 30 7150 – 7200 kV/ms V . . 50 50 500 O . . 50 70 100 mA Grid 1 Grid 1 drive current (DC) Heaters Cathode heater voltage . . . . 5.8 Reservoir heater voltage . . . . 5.8 6.8 6.8 7.0 7.0 V V CHARACTERISTICS Anode delay time (see note 18) . . . . . . . – Rate of rise of anode current (see notes 18 and 19) . . . . – Time jitter (see note 20) . . . . – CX1157, page 2 30 100 51.0 75 ns – kA/ms 2.0 ns 1. The reservoir heater supply must be obtained either from the cathode heater supply or if a separate supply is used it must be decoupled to avoid damage to the reservoir. 2. The tube must be mounted by means of its mounting flange. 3. The maximum permissible peak forward voltage for instantaneous starting is 16 kV and there must be no overshoot. 4. The peak inverse voltage including spike must not exceed 5.0 kV for the first 25 ms after the anode pulse. 5. For single-shot or burst mode applications this parameter can exceed 100 kA/ms. The ultimate value which can be attained depends to a large extent upon the external circuit. 6. This rate of rise refers to that part of the leading edge of the pulse between 25% and 75% of the pulse amplitude. 7. 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. 8. The tube may be operated with a loaded grid 2 bias voltage of 0 to 750 V provided that care is taken to ensure that the peak grid 1 drive current is sufficiently low to prevent triode firing (tube control by the grid 1 pulse). 9. When DC priming is used on grid 1, a negative bias of 100 to 200 V must be applied to grid 2 to ensure anode voltage hold-off. DC priming is especially suitable in crowbar service. 10. Typical figures are obtained on test using conditions of minimum grid drive. Improved performance can be expected by increasing grid drive. Maximum life is obtained with a grid 1 pre-pulse. 11. DC negative bias voltages must not be applied to grid 1. When grid 1 is pulse driven, the potential of grid 1 may vary between 710 and +5 V with respect to cathode potential during the period between the completion of recovery and the commencement of the succeeding grid pulse. 12. To ensure a high standard of ruggedness, all tubes are subjected to the following tests. After each mechanical test all the tubes must then satisfy all electrical tests. (a) Vibration – The tubes are vibrated at 50 Hz with acceleration of 10 g for one minute in the direction of the cathode axis and then in one direction perpendicular to the cathode axis. See note 2. (b) Recovery Time – The tubes are tested for recovery at zero grid 2 bias voltage with a maximum limit of 35 ms. The tubes are subjected to the following tests on a sampling basis. (c) Operation under Vibration – The tubes are vibrated at 10 g in each of three planes at a sweep rate of one octave per minute from 20 to 500 to 20 Hz, under normal operating conditions. See note 2. #E2V Technologies 13. 14. 15. 16. 17. 18. 19. 20. (d) Survival under Vibration and Heater Cycling – The tubes are vibrated at 10 g at a sweep rate of one octave per minute from 5 to 500 Hz for 70 hours in each plane together with heater cycling of a 10 minute on/off cycle. See note 2. (e) Long Duration Shock – The tubes are tested at 125 g for 10 ms with two blows in each plane. See note 2. (f) High Temperature Test – The tubes are tested at a base temperature of 220 8C and an anode temperature of 250 8C under normal operating conditions for 5 hours. This implies an ambient temperature of 130 8C. (g) Low Temperature Instant Start – The tubes are cooled to 720 8C and subjected to a 3-minute warm up period with 5.8 V on the heater. The tubes must withstand a snap start at 10 kV and operate satisfactorily. (h) Standby-Life – The tubes are run with 6.3 V heater voltage applied for 500 hours. The time interval between the instant when the unloaded grid 2 voltage passes cathode potential and the instant when anode conduction takes place. The drift in delay time over a period from 10 seconds to 10 minutes after reaching full voltage. The recovery characteristics are controlled on a sampling basis. For crowbar applications where the tube is required to hold off DC anode voltage for longer than 20 ms, the maximum peak forward anode voltage is 16 kV. If the reservoir voltage is increased above normal, the DC hold-off voltage may be reduced. For pulse durations not exceeding 0.25 ms. Shorter anode delay time and higher rate of rise of anode current may be obtained by increasing the cathode and reservoir heater voltages from 6.3 V to 6.8 V. The rate of rise of anode current obtainable is also dependent on the total circuit inductance and transmission line type matching. With the grid drive conditions specified, the anode delay time jitter will normally be less than 1.0 ns. #E2V Technologies 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. CX1157, page 3 OUTLINE (All dimensions without limits are nominal) 1C 2395C ANODE CONNECTION FITTED WITH 8-32 UNC SCREW SEE NOTE 4 E A GRID 1 CONNECTION 2 HOLES 1M GRID 2 CONNECTION 2 HOLES 1L P F G MOUNTING FLANGE SEE NOTE 1 1D SEE NOTE 3 J SEE NOTE 2 SEE NOTE 5 8 HOLES 1N EQUISPACED ON H PCD RESERVOIR HEATER LEAD (RED) K LONG, TAG TO SUIT 1Q 1B CATHODE HEATER LEAD (YELLOW) K LONG, TAG TO SUIT 1Q Ref Millimetres Inches A B C D E F G H J K L M N P Q 76.2 max 57.15 44.45 + 0.79 36.5 5.59 + 0.38 24.9 17.78 51.59 + 0.25 31.75 min 152.4 3.05 3.05 4.19 2.54 4.19 3.000 max 2.250 1.750 + 0.031 1.437 0.220 + 0.015 0.980 0.700 2.031 + 0.010 1.250 min 6.000 0.120 0.120 0.165 0.100 0.165 Inch dimensions have been derived from millimetres. Outline Notes 1. The mounting flange is the connection for the cathode, cathode heater return and reservoir heater return. 2. A minimum clearance of 31.75 mm (1.250 inches) must be allowed below the flange. 3. The recommended mounting hole is 38.10 mm (1.500 inches) diameter. 4. The anode temperature is measured at the base of the anode stem. 5. The base temperature is measured at this point. CX1157, page 4 #E2V Technologies MAXIMUM RECOVERY CHARACTERISTICS 40 2396B PEAK ANODE CURRENT 300 A RE-APPLIED ANODE VOLTAGE 1 kV 35 GRID 2 VOLTAGE 0 V 30 712.5 25 725 MAXIMUM RECOVERY TIME (ms) 20 750 7100 15 10 5 0 100 500 GRID 2 RECOVERY IMPEDANCE (O) 1000 5000 10 000 50 000 SCHEMATIC DIAGRAM GRID 2 DELAYED WITH RESPECT TO GRID 1 7938 GRID 2 VOLTAGE 750 V, 1 ms CATHODE HEATER SUPPLY RESERVOIR HEATER SUPPLY G2 R2 G1 R1 0 NEGATIVE BIAS VOLTAGE GRID 1 CURRENT 0.5 A, 2 ms C1 0.5 ms MIN GRID 1/GRID 2 DELAY C2 (VARIABLE) RECOMMENDED GRID, CATHODE AND RESERVOIR HEATER CONNECTIONS R1 = Grid 1 series resistor. 12 W vitreous enamelled wirewound is recommended, of a total impedance to match the grid 1 drive pulse circuit. R2 = Grid 2 series resistor. 12 W vitreous enamelled wirewound is recommended, of an impedance to match the grid 2 drive pulse circuit. C1, C2 7 reservoir protection capacitors with a voltage rating 5500 V; C1 = 1000 pF low inductance (e.g. ceramic), C2 = 1 mF (e.g. polycarbonate or polypropylene). Components R1, R2, C1 and C2 should be mounted as close to the tube as possible. 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. #E2V Technologies Printed in England CX1157, page 5