Hi rossyb,
Welcome to the board.
You have to be a bit more specific to get the best help. A frequency of 65KHz is very high for an arduino, do you want to sample it or do you just need the amplitude. I suspect what you want to do is possible but not simply by plugging a high frequency into an arduino.
How is the information conveyed from your sensor? Is it frequency, amplitude? A link to the sensor would be good.