ETC CX1157

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: 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-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