Thyratron Grid Driver

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The Thyratron Driver is an air-cooled, high-voltage pulse amplifier in a rackmount enclosure. Designed to generate a high-voltage, steep-rise-time pulse to the control grid G2 and a DC bias for pre-ionization to the control grid G1, it is well-suited for triggering gas-filled thyratrons. 

System Operation 

The high-voltage pulse for the thyratron control grid G2 can be generated from an external remote source or locally with the internal signal generator. The specification of the output pulse for the thyratron control grid G2 is as follows:

• Amplitude   (egy): 2.0 kV 
• Duration  (tpg): 2 usec
• Time of Rise  (trg): 200 nsec
• Source Impedance (Zg): 75 Ohm

Direct Current (DC) pre-ionization signal that primes the ion discharge, reducing the pulse trigger jitter, is generated for the control grid G1. The specification of the DC signal for the thyratron control grid G1 is as follows:

• Voltage : +180 VDC
• Current : 70 mA

Since DC pre- ionization is utilized, the G2 pulse is negatively biased with -180 VDC to prevent accidental pulse triggering on the G2 control grid. 

Low-voltage Trigger Source

The source of the 5V-TTL pulse trigger can be from an external remote source or the internal signal generator. The external trigger enters on a BNC connector on the front panel. The internal signal generator has two independent channels with the pulse parameters (i.e., frequency, pulse-width, voltage level) controlled using the front panel softkeys and knobs. The signal generator default pulse-width is 2 msec with frequency set at 160 Hz and 320 Hz for channel 1 and channel 2, respectively. The default pulse parameters can be overridden using the front panel controls.

Remote Control and Interlocks

Remote logic control for selecting trigger source, routing trigger pulse, and interlock on/off is implemented. The logic control is accessed via a terminal block on the rear panel. The logic control commands the relays that route the pulse trigger.

Control Grid Output Voltage

The output signals to the thyratron control grids are outputted on 5kV Safe High Voltage (SHV) connectors. Both the control grid G1 and G2 output signals are grounded with cathode ground.

General Info

Input power requirement is nominal 120 VAC, 60 Hz. The dimension of the enclosure is 17”x13”x7” (WxDxH). The enclosure is 4U on a standard 19” rack.