E2V Technologies CX1594 Deuterium Filled, Hollow Anode, Five-Gap Ceramic Thyratron The data to be read in conjunction with the Hydrogen Thyratron Preamble. ABRIDGED DATA Hollow anode, deuterium filled, five-gap thyratron with ceramic envelope, featuring high peak current, high rate of rise of current, low jitter and voltage/current reversal. The patented hollow anode structure enables the tube to cope with inverse voltage and current without consequent reduction in its high voltage hold-off capability due to electrode damage. A reservoir normally operated from a separate heater supply is incorporated. The reservoir heater voltage can be adjusted to a value consistent with anode voltage hold-off in order to achieve the fastest rate of rise of current possible from the tube in the circuit. Modulator Service Peak anode voltage (see note 1) Peak forward anode current . . Peak reverse anode current . . Average anode current . . . . . . . . . . . . . . . . 150 . 10 . . 5 . . 3.0 kV kA kA A max max max max . . . . . . . . . . . . . . . . kV kA kA C max max max max Crowbar Service Peak anode voltage (see note 1) Peak forward anode current . . Peak reverse anode current . . Conducted charge . . . . . 125 40 20 18 GENERAL Electrical Mechanical Seated height (flange to flange) . . Clearance required below flanges . . . . Overall diameter (mounting flange) . . Net weight . . . . . Mounting position (see note Tube connections . . . . 566.0 mm (22.283 inches) max . . 57.15 mm (2.250 inches) min . 152.4 mm (6.000 inches) nom . . . 13 kg (29 pounds) approx 3) . . . . . . . . . any . . . . . . . . see outline Cooling For all applications, cooling by oil or coolant immersion is desirable. Further information is contained in the relevant section of the Preamble. At and below 55 kV the CX1594 may be cooled by forced-air directed mainly onto the base, and the ceramic envelope should be maintained below the maximum rated temperature. An air flow of at least 2.83 m3/min (100 ft3/min), depending on the mechanical layout, will be necessary to keep the tube operating temperatures under the limits specified below. In addition to 300 W of heater power, the tube dissipates from 100 W per ampere average anode current, rising to 300 W/A at the highest rates of rise and fall of anode current. The cathode end of the tube must be cooled whenever heater voltages are applied, since the cathode flange will reach a temperature of 120 8C above ambient in the absence of cooling. Envelope temperature: ceramic, anode and grids . . . . . . 150 8C max cathode flange and base . . . . . . 120 8C max 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) . Inter-electrode capacitances (each gap) . . . . . . . . 2) . . . . . . . . . . . . . . . . . . oxide coated + 0.3 . 6.3 V 7 0.0 40 A . 5.0 V 10 A 15 min 40 pF approx 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-CX1594 Issue 2, October 2002 527/5640 Cathode MAXIMUM AND MINIMUM RATINGS These ratings cannot necessarily be used simultaneously, and no individual rating must be exceeded. Anode (Pulse Modulator Service) (See notes 4 and 5) . . . . Max + 0.3 Heater voltage . . . . . . . . . 6.3 7 0.0 Heating time . . . . . . . . 15 – V min Reservoir Min Typical Max Peak forward or inverse anode voltage (see notes 1 and 6) . Peak forward anode current . Peak reverse anode current . . Average anode current . . . Rate of rise of anode current (see notes 7 and 8) . . . . Pulse repetition rate (see note 4) . . . . . . Min – – – – – – – – 150 10 5 3.0 kV kA kA A . – 10 – kA/ms . – 100 – pps Heater voltage (see note 2) . . . . . 4.5 Heating time . . . . . . . . 15 6.5 – V min Environmental Ambient temperature . . . . . . 750 Altitude . . . . . . . . . . . – – +90 3 10 000 8C km ft CHARACTERISTICS Min Typical Max Anode (Single-Shot or Crowbar Service) (See note 9) DC forward anode voltage . . Peak anode current . . . . Conducted charge: capacitor discharge . . . crowbar service (see note 10) Repetition frequency . . . . . . . . . . . . 125 40 kV max kA max . . . . . 0.6 C max . . . . 18 C max . . . 1 pulse per 10 s max Grid 2 Min Unloaded grid 2 drive pulse (see note 11) . . . . Grid 2 pulse duration . . Rate of rise of grid 2 pulse (see note 8) . . . . Grid 2 pulse delay . . . Peak inverse grid 2 voltage Loaded grid 2 bias voltage Forward impedance of grid 2 drive circuit . . voltage . . . . 500 . . . . . 1.0 . . . . . . . . . . . . Max 2000 – V ms . 10 – kV/ms . . 0.5 3.0 ms . . – 450 V . 750 7150 V . . . . 50 500 O 150 150 V mA Grid 1 – DC Primed (See note 9) DC grid 1 unloaded priming voltage . DC grid 1 priming current . . . . 75 75 Grid 1 – Pulsed (See notes 5, 9 and 12) Unloaded grid 1 drive pulse (see note 11) . . . . Grid 1 pulse duration . . Rate of rise of grid 1 pulse (see note 8) . . . . Peak inverse grid 1 voltage Loaded grid 1 bias voltage Peak grid 1 drive current CX1594, page 2 voltage . . . . 400 . . . . . 2.0 . . . . . . . . . . . . . . . . 1000 – V ms . 1.0 – kV/ms . – 450 V . . . . see note 12 . 0.5 1.5 A Critical DC anode voltage for conduction (see note 13) . Anode delay time (see notes 13 and 14) . . Anode delay time drift (see notes 13 and 15) . . Time jitter (see note 13) . . Cathode heater current (at 6.3 V) . . . . . . Reservoir heater current (at 5.0 V) . . . . . . . . – 7.0 . . – 0.15 10.0 0.35 kV ms . . – . . – 15 1.0 50 5.0 ns ns . 40 45 A 10 12 A 35 . . 8.0 NOTES 1. At and below 55 kV the CX1594 may be operated in air. Above this level the tube must be operated in oil or coolant immersed. 2. The reservoir heater must be decoupled with suitable capacitors to avoid damage by spike voltages. The recommended reservoir heater voltage is stamped on individual tube envelopes. 3. The tube must be mounted using its mounting flange. 4. Triggered charging techniques are recommended because the tube has a relatively long recovery time (100 – 200 ms). 5. Pre-pulsing of grid 1 is recommended for modulator and high rate of rise of current applications. 6. This is the maximum hold-off voltage in either direction before the tube is triggered. The maximum permissible peak forward voltage for instantaneous starting is 100 kV and there must be no overshoot. 7. 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. 8. This rate of rise refers to that part of the leading edge of the pulse between 25% and 75% of the pulse amplitude. #E2V Technologies 9. When DC priming is used on grid 1, a negative bias of 100 to 150 V must be applied to grid 2 to ensure anode voltage hold-off. DC priming is recommended for crowbar service. 10. In crowbar service, most of the coulombs are often in the power supply follow-on current rather than the storage capacitor discharge. 11. 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. (See schematic diagram, page 5). 12. 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. 13. Typical figures are obtained on test using conditions of minimum grid 2 drive. Improved performance can be expected by increasing grid drive. 14. 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. 15. The drift in delay time over a period from 10 seconds to 10 minutes after reaching full voltage. #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. CX1594, page 3 SCHEMATIC DIAGRAM (Crowbar Service) 7252 ANODE (+) R2 R1 R2 R1 R2 R1 R2 R1 R1 R1 R1 R1 R2 G2 R3 TRIGGER PULSE C1 G1 CATHODE HEATER SUPPLY RESERVOIR HEATER SUPPLY C2 R4 150 V dc SUPPLY C3 (VARIABLE) 7150 V BIAS CATHODE (7) R1 R2 = = 470 O 12 W vitreous enamelled wirewound resistors. 10 to 25 MO high voltage resistors with a power rating consistent with forward anode voltage. R3 = Grid 2 series resistor. 12 W vitreous enamelled wirewound is recommended, of an impedance to match the grid 2 drive pulse circuit. R4 = Grid 1 series resistor. 12 W vitreous enamelled wirewound is recommended. C1 = 500 to 1000 pF capacitor with a voltage rating 530 kV. C2, C3 = Reservoir protection capacitors with a voltage rating 5500 V; C2 = 1000 pF low inductance (e.g. ceramic), C3 = 1 mF (e.g. polycarbonate or polypropylene). Components R3, R4, C2, and C3 should be mounted as close to the tube as possible. CX1594, page 4 #E2V Technologies SCHEMATIC DIAGRAM (Modulator Service) ANODE (+) 7251 R1 R2 C1 R2 C1 R1 R2 C1 R1 R2 C1 R1 R2 C1 R1 R1 R1 GRID 2 DELAYED WITH RESPECT TO GRID 1 R1 GRID 2 VOLTAGE 500 – 2000 V, 1 ms R1 CATHODE HEATER SUPPLY G2 R3 G1 R4 0 NEGATIVE BIAS VOLTAGE GRID 0/GRID 1 CURRENT 0.5 – 1.5 A, 2 ms 0.5 ms MIN GRID 1/GRID 2 DELAY C2 C3 RESERVOIR HEATER SUPPLY (VARIABLE) CATHODE (7) R1 R2 = = 470 O 12 W vitreous enamelled wirewound resistors. 5 to 20 MO high voltage resistors with a power rating consistent with forward anode voltage. R3 = Grid 2 series resistor. 12 W vitreous enamelled wirewound is recommended, of an impedance to match the grid 2 drive pulse circuit. R4 = Grid 1 series resistor. 12 W vitreous enamelled wirewound is recommended, of an impedance to match the grid 1 drive pulse circuit. C1 = 500 pF capacitors with a voltage rating equal to the peak forward voltage. These capacitors may be required to balance the voltages across each gap if the anode voltage rises in less than 5 ms. C2, C3 = Reservoir protection capacitors with a voltage rating 5500 V; C2 = 1000 pF low inductance (e.g. ceramic), C3 = 1 mF (e.g. polycarbonate or polypropylene). Components R3, R4, C2, and C3 should be mounted as close to the tube as possible. #E2V Technologies CX1594, page 5 OUTLINE (All dimensions without limits are nominal) 1C 7250 ANODE CONNECTION FITTED WITH 1 /4-20 UNC SCREW ALL GRID CONNECTIONS FITTED WITH 8–32 UNC SCREWS A T R GRID 2 P M U S Q N L D SEE NOTE 2 MOUNTING FLANGE SEE NOTE 1 1F SEE NOTE 3 GRID 1 LEAD (GREEN) G LONG, TAG TO SUIT 1H RESERVOIR HEATER LEAD (RED) G LONG, TAG TO SUIT 1H 1B 4 MOUNTING HOLES 1J EQUISPACED ON K PCD CATHODE HEATER LEAD (YELLOW) G LONG, TAG TO SUIT 1H CX1594, page 6 #E2V Technologies Ref Millimetres Inches A B C D F G H J K L M N P Q R S T U 566.0 max 152.4 147.0 3.18 106.36 max 177.8 min 6.35 8.0 135.74 119.9 197.8 216.0 285.5 303.7 373.2 391.4 460.9 479.3 22.283 max 6.000 5.787 0.125 4.187 max 7.000 min 0.250 0.315 5.344 4.720 7.787 8.504 11.240 11.957 14.693 15.409 18.146 18.870 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 57.15 mm (2.250 inches) must be allowed below the mounting flange. 3. The recommended mounting hole is 108 mm (4.25 inches) diameter. 4. The holes for all grid connections will be in line with the hole in the mounting flange to within 108 either side of the hole centre. 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 CX1594, page 7