E2V Technologies CX1191D Deuterium Thyratron - Alphatron

E2V Technologies 

CX1191D 

Deuterium Thyratron 

The data to be read in conjunction with the Hydrogen 

Thyratron Preamble. 

ABRIDGED DATA 

Deuterium-filled tetrode thyratron of ruggedised construction, 

suitable for use in airborne or mobile military radar systems. It is 

used for switching peak powers up to 8.0 MW at high repetition 

rates under a wide range of operating conditions. It has a 

rugged, internally connected reservoir. Samples are subjected 

to extensive environmental test procedures including vibration 

at 2g from 50 to 200 Hz. 

Peak forward anode voltage . . . . . . 35 kV max 

Peak anode current . . . . . . . . 500 A max 

Average anode current . . . . . . . 0.5 A max 

Anode heating factor . . . . . . 8.0 x 10 9 VApps max 

Peak output power . . . . . . . . . 8.0 MW max 

GENERAL 

Electrical 

Cathode (connected internally 

to one end of heater) . . . . . . . . oxide coated 

Heater voltage . . . . . . . . . . 6.3 + 7 1 / 2 %V 

Heater current . . . . . . . . . 12.5 A 

Tube heating time (minimum) (see note 1) . 5.0 min 

Inter-electrode capacitances (approximate): 

anode to grid 2 (grid 1 

and cathode not connected) . . . . 9.0 pF 

anode to grid 1 (grid 2 

and cathode not connected) . . . . 4.5 pF 

anode to cathode (grid 1 

and grid 2 not connected) . . . . 18 pF 

Mechanical 

Overall length . . . . . 223.8 mm (8.812 inches) max 

Overall diameter . . . . . . 65.1 mm (2.562 inches) max 

Net weight . . . . . . . . 340 g (12 ounces) approx 

Mounting position (see note 2) . . . . . . . . . any 

Base . . . . . . . . . . . . . . B4D, bayonet 

Top cap . . . . . . . . . . . . . BS448-CT3 

Cooling (See note 3) . . . . . . . . . . natural 

E2V Technologies Limited, Waterhouse Lane, Chelmsford, Essex CM1 2QU England Telephone: +44 (0)1245 493493 Facsimile: +44 (0)1245 492492 

e-mail: enquiries@e2vtechnologies.com 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: enquiries@e2vtechnologies.us 

# E2V Technologies Limited 2002 A1A-CX1191D Issue 3, October 2002 

527/5630

PULSE MODULATOR SERVICE 

MAXIMUM AND MINIMUM RATINGS 

(Absolute values) 

Min Max 

Anode 

Peak forward anode voltage 

(see note 1) . . . . . . . . – 35 kV 

Peak inverse anode voltage 

(see note 4) . . . . . . . . – 10 kV 

Peak anode current . . . . . . – 500 A 

Average anode current . . . . . – 0.5 A 

Rate of rise of anode current 

(see note 5) . . . . . . . . – 2500 A/ms 

Anode heating factor . . . . . . – 8.0 x 10 9 VApps 

Min Max 

Grid 2 

Unloaded grid 2 drive pulse voltage 

(see note 6) . . . . . . . . 200 750 V 

Grid 2 pulse duration . . . . . . 1.0 – ms 

Rate of rise of grid 2 pulse 

(see note 5) . . . . . . . . 1.0 – kV/ms 

Grid 2 pulse delay . . . . . . . 0.5 3.0 ms 

Peak inverse grid 2 voltage . . . . – 200 V 

Loaded grid 2 bias voltage . . . 750 7120 V 

Forward impedance of 

grid 2 drive circuit . . . . . . 100 1000 O 

Grid 1 – DC Primed (See note 7) 

DC grid 1 unloaded priming voltage . 75 150 V 

DC grid 1 priming current . . . . 50 100 mA 

Grid 1 – Pulsed 

Unloaded grid 1 drive pulse voltage 

(see note 6) . . . . . . . . 300 750 V 

Grid 1 pulse duration . . . . . . 2.0 – ms 

Rate of rise of grid 1 pulse 

(see note 5) . . . . . . . . 1.0 – kV/ms 

Peak inverse grid 1 voltage . . . . – 200 V 

Loaded grid 1 bias voltage . . . . . . . . see note 8 

Peak grid 1 drive current . . . . 0.3 1.0 A 

Cathode 

Heater voltage . . . . . . . . . 6.3 + 7 1 / 2 % V 

Tube heating time (see note 1) . . 5.0 – min 

Environmental 

Environmental performance . . . . . . . see note 9 

Ambient temperature . . . . . 755 +90 8C 

Altitude . . . . . . . . . . – 3 km 

– 10 000 ft 

CHARACTERISTICS 

Min Typical Max 

Critical DC anode voltage for 

conduction (see note 10) . . . – 0.3 1.0 kV 

Anode delay time 

(see notes 10 and 11) . . . . – 0.15 0.25 ms 

Anode delay time drift 

(see notes 10, 12 and 13) . . – 20 50 ns 

Time jitter (see notes 10 and 13) . – 1.0 5.0 ns 

Heater current (at 6.3 V) . . 11 12.5 13 A 

RATINGS FOR SINGLE-SHOT OR 

CROWBAR SERVICE (See note 7) 

DC forward anode voltage (see note 1) . . 35 kV max 

Peak anode current . . . . . . . 5000 A max 

Product of peak current and 

pulse duration . . . . . . . . . . 0.2 A.s max 

Repetition frequency . . . . . . . 1 pulse per 10 s max 

NOTES 

1. The maximum permissible peak forward voltage for 

instantaneous starting is 20 kV and there must be no 

overshoot. 

For single-shot and crowbar applications, each tube is 

tested to withstand 35 kV DC at 6.3 V heater voltage for 

10 minutes, with 100 mA grid 1 drive current and 7100 V 

grid 2 bias. 

2. Clamping is only permissible by the base. 

3. In some applications, air cooling may be necessary to 

prevent the base temperature from exceeding 200 8C. 

4. The peak inverse voltage must not exceed 25 kV for the 

first 25 ms after the anode pulse. 

5. The rate of rise refers to that part of the leading edge of the 

pulse between 25% and 75% of the pulse amplitude. 

6. Measured with respect to cathode. In certain cases the 

maximum drive pulse voltage may be exceeded without 

damage to the tube; a maximum value of 2.5 kV is then 

recommended. 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. 

7. 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 recommended for pulse modulator 

and crowbar service. 

8. 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. 

CX1191D, page 2 

# E2V Technologies

9. All tubes are subjected to an acceleration of 10 g at 50 Hz 

before testing. In addition, samples are tested under the 

following conditions: 

(a) Linear Acceleration 12 g (min) is applied and 

maintained for 1 minute at right angles to and in each 

direction along the major axis of the tube. A heater 

voltage of 6.3 V is applied during the test. 

(b) Resonance Search Vibration is applied in two 

mutually perpendicular directions, one of which is 

parallel to the longitudinal axis of the tube. The 

frequency is swept at a rate not exceeding one 

octave per minute between 10 and 200 Hz, with 

accelerations of 2 g (min). All resonances detectable 

visually or electrically are noted for information and 

also for use in test (c). Normal operating voltages are 

applied during the test. 

(c) Vibration Fatigue Each tube is subjected to vibration 

for two periods of ten hours. In one period the 

direction of vibration is parallel to the longitudinal axis 

of the tube, and in the other the direction is 

perpendicular to the longitudinal axis of the tube. An 

acceleration of 2 g is used and the frequency is that of 

the strongest resonance detected during the 

resonance search. If no resonances were detected in 

the search, then a frequency of 150 Hz is used. A 

heater voltage of 6.3 V is applied during the test. 

Tubes must pass operational tests after the above 

procedure has been completed. 

10. Typical figures are obtained on test using conditions of 

minimum grid drive. Improved performance can be 

expected by increasing the grid drive. 

11. 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. 

12. The drift in delay time over a period from 10 seconds to 

10 minutes after reaching full voltage. 

13. For equipment where jitter and anode delay time drift are 

not important, the tube may be triggered by applying a 

single pulse to grid 2 and connecting grid 1 to grid 2 via a 

1000 pF capacitor shunted by a 0.1 MO resistor. 

14. For screened grid operation, grid 2 may be connected to 

cathode provided that a low impedance grid drive pulse 

(say 50 O) is used. Under these conditions the critical DC 

anode voltage for conduction may be higher than normal. 

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. 

# E2V Technologies CX1191D, page 3

OUTLINE 

(All dimensions without limits are nominal) 

2953A 

1D 

Ref Millimetres Inches 

C 

A 217.5 + 6.4 8.562 + 0.250 

B 65.08 max 2.562 max 

C 12.7 min 0.500 min 

D 14.38 + 0.18 0.566 + 0.007 

E 15.88 0.625 

F 14.28 0.562 

G 19.05 0.750 

H 4.750 + 0.076 0.187 + 0.003 

J 25.4 1.000 

Millimetre dimensions have been derived from inches. 

A 

1B 

Pin 

Element 

1 Grid 1 

2 Heater, cathode 

3 Heater 

4 Grid 2 

Top cap Anode 

E 

SUPER JUMBO 

B4D BASE 

WITH BAYONET 

4 PINS 1H 

ON J PCD 

3 

4 

F 

2 

1 

G 

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. 

CX1191D, page 4 

Printed in England 

# E2V Technologies

E2V Technologies CX1191D Deuterium Thyratron - Alphatron

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