Reading SRI test report, I was little bit disappointed that they are using proprietary signal generator to get their 80A/100ns pulses. However, as has been stated by many replicators, probably the short and fast current pulses (i.e. with broad frequency spectrum) is essential to trigger LENR reaction.
So I started thinking what is feasible and controllable way to produce something similar to their so-called "Q Pulses".
Personally, I have very successful experience using high voltage gallium-nitride (GaN) FET transistors from GaN Systems for building various high efficiency power converters. Also I'm fun of STM32 microcontrollers, and there is a chip STM32F3348 with high resolution PWM timer (217 ps), exactly for precise generation of short pulses (or high frequency PWM).
So I put together the 32F3348DISCOVERY evaluation board for microprocessor, and one floating in my lab GS66508T-EVBHB evaluation board which is half-bridge made using GS66508T transistors (650V, 30A). Also prepared some simple firmware for 100ns pulse generation (Github).
Here is the picture:
The control signals for high and low side switches are going from microcontroller board. The output of the half bridge was loaded to ground by matched 50ohm resistor (connected by standard RG58 coaxial cable). Input DC voltage is +300V, so at 50ohms this is 6A, which is not a lot -- but enough to start.
Here is the picture of output voltage measured across the load (resistor) side. So the rise time is about 10ns for 300V or equivalently 10ns for 6A.
The actual transistor (GS66508T) is capable for 30A of short pulses, however I used also GS66516T which is 60A part and more close to desired power.
So my plan is to gradually increase the power to at least 30A using the existing half-bridge board (I should source or make some coaxial cables with lower impedances). And then switch to 60A FETs.
As a result, I'm going to propose some ready-made hardware for LENR enthusiasts, which will be a set of evaluation and custom boards. The custom board probably will be control module using STM32F3348 microcontroller (open source and open hardware, and I will sell it from my Tindie store), with maybe some external computer software to configure power level.
Please let me know (by liking this post) if you are interested in these efforts...