[Laser] ultra-fast S/H and Positive or Negative Peak Detector circuit

[robotics]

I need ultra-fast S/H and Positive or Negative Peak Detector circuit for
nuclear pulses of <5ns rise time and 200ns fall time pulse, required hold
time 2us to 12-bit accuracy. If any one of you have good schematic for this
application then kindly give me a link with part number and details. I need
a working circuit and not just ideas that may or may not work.

Thanks in advance.

Shyam Sunder Tiwari, Ph. D.
Managing Director
Sensors Technology Private Limited
AM-51 Deen Dayal Nagar, Gwalior, MP 474020, India
Tel: +91-751-470680 Fax: +91-751-545716 Email: robotics@mantrafreenet.com