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Indigenous development of microwave tubes like 2MW S-Band pulsed magnetrons,
5MW S-Band pulsed klystron, 3MW S-Band pulsed magnetrons and 40kV, 3kA high
voltage thyratrons was taken up by, to have self reliance in the field of
microwave devices and to have their consistent supply for the Indian accelerator
programme RRCAT in collaboration with CEERI, Pilani under BRNS funding., RRCAT
initiated development of 2MW S-Band pulsed magnetrons in collaboration with
CEERI, Pilani. The design, development and testing of the microwave test
facilities for ageing, conditioning and performance testing of Indian
magnetrons, was successfully done by RRCAT indigenously. After the rigorous
testing, the test facility was shifted, installed and commissioned at CEERI,
Pilani by RRCAT. Over a period of 10 years, nine prototypes were aged and
tested, two magnetrons were life tested and two magnetrons under production
programme have been successfully conditioned and tested. Testing of more numbers
is underway. Under this 9 prototypes were developed and tested on the
facilities developed by RRCAT and after successful development of the magnetrons
in the prototype mode Pilot production of 2MW magnetrons was entrusted upon
CEERI by RRCAT under BRNS project.
Pilot Production of 2MW
S-Band Magnetrons:
Development of prototypes of 2MW magnetron was completed and pilot production of
this tube has been done at CEERI , Pilani. Seven tubes under pilot production
have been fabricated and their testing is in progress.
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Table 2 Indigenous
pulse modulator Characteristics |
|
Pulse o/p voltage |
kV max |
7.5 |
|
O/p Pulse duration |
µs |
5 |
|
Pulse o/p current |
A min |
700 |
|
Pulse repetition rate |
Hz |
1-250 |
|
Average o/p power |
kW min |
5 |
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Table 3 Indigenous pulse
transformer specs |
|
Pulse o/p voltage |
kV max |
47 |
|
O/p Pulse duration |
Μs |
5 |
|
Pulse o/p current |
A max |
110 |
|
Pulse rise time |
μs |
0.6 |
|
Pulse fall time |
Μs |
0.8 |
|
Average o/p power |
kW min |
5 |
|
Turns ratio |
|
1:6 |
|
Pulse top droop |
% |
<1.6 |
|
Pulse duration |
|
5 |
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Table 1
Specifications of Indigenous 2MW S-Band magnetron |
|
Peak
output power |
2 MW |
|
Average
power |
2 kW |
|
Frequency
range |
2991-3004
MHz |
|
RF pulse
duration |
4 micro
sec |
|
Repetition
rate |
250 Hz |
|
Peak Anode
voltage |
42 kV |
|
Peak anode
current |
100 amp |
Indigenous development of 5
MW S-Band pulsed klystrons:
RRCAT took up development of 5MW S-Band klystrons indigenously in collaboration
with CEERI Pilani. The development of klystron prototype is completed. These
klystrons are very crucial devices, for energizing the 10-20 MeV electron
accelerators1, which are developed in the country for various
industrial, medical and scientific applications. A test station has been
developed indigenously at RRCAT for these klystrons. It consists of a 12 MW peak
power 130kV klystron pulse modulator, a 1: 10 pulse transformer, 130kV high
voltage deck having high voltage pulse divider, pulse current transformer as
well indigenously built klystron socket, filament supplies, klystron support
structure and pulse transformer oil tank. After development /rigorous testing
the test stand was shifted to CEERI and was installed and commissioned there by
RRCAT. Gun collector test module and prototypes of the 5MW klystron were tested,
aged and conditioned at high power using this test stand. Three prototypes of
the klystron have been successfully fabricated and tested.
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Table
1 Specifications of Indian 5MW S-Band klystron
Peak power output 5 MW
Frequency of operation 2856 ±2.5 MHz
Gain 50 dB
Efficiency 40 %
Pulse duration 5 msec
Beam voltage max. 130 kV
Beam current, max. 95 A
Heater voltage 8 V
Heater current 35 A
RF
output wave guide WR 284
RF
input N type coaxial
Cooling Liquid
Focusing Electromagnet |
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Table 2 Klystron
Modulator Specifications |
|
Beam voltage 130 kV max. |
|
Beam current 95 A. max. |
|
Pulse width 5 msec
Pulse repetition rate 250 Hz |
|
Heater voltage 8 V |
|
Heater current 35 A. |
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Table
3 Specifications of pulse transformer |
|
Output pulse
voltage 130 kV max. |
|
Output pulse
current 95 A. |
|
Turns
ratio 1:10 |
|
Rise
time 0.8 msec |
|
Fall time
1 msec |
|
Insulation oil |


3MW
magnetrons:
Two prototypes
under the project have been fabricated and testing in the test station at RRCAT is
under way.
40KV
Thyratrons: So far four prototypes under this project have been developed and
supplied to RRCAT for partial testing. Two have been tested for limited ratings.
Fifth prototype has also been fabricated at CEERI.
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