60W 40kHz Ultrasonic Transducer Circuit: SCR Trigger, 555 Astable, R/C Values?

Hello, I'm trying to make this circuit(attached) but I need different components to adhere to my transducer.. I have a 60 watt, 40kHz ultrasonic transducer that requires excitation voltage of 600V. Rn I'm struggling with the 4th part, which uses 2 scr to trigger the storage capacitor, thus running the unit.

Can anyone help me find values for resistor and capacitor? Also I am not sure why the 555 is in astable mode if the capacitor in the high voltage pulse generator only needs the scr to turn on once to activate capacitor, exciting the transducer and starting oscillation?


Any help would be appreciated, I've only started learning a month ago at home and I absolutely must make this transducer run, it's why I started.


Thank you!

This is the pdf I got my info from. It seems you must start with RC values, the smaller RC the better for exciting high frequency transducers (circuit is designed for frequencies between 0.25 and 2.2MHz), but R must be smaller then the max current allocated by scr's