Hurricane Harvey

A project log for Gamma Ray Spectroscopy - small, cheap

The goal of this project is to design a light weight gamma ray scintillator in a 1u CubeSat frame

sparks.ronsparks.ron 09/09/2017 at 03:110 Comments

Life is amazingly adept at throwing "curve balls" that can bend you out of shape and ruin your plans.  It has been a lot that way here lately.  The latest massive disruptor was named Hurricane Harvey.  It revved up in only 3-4 days from a disturbance to a Cat 5 hurricane.  That is precious little time to prepare anyway.  But in this case preparations were not enough.  No forecaster had ever dreamed of an event this large, let alone one that stuck in basically the same area for 4 days.

Thankfully I did a lot of research before building our place and it paid off.  We had no flooding around our home or shop.  The amount of water was unbelievable.  At our bunkhouse/ham radio clubhouse we have an 18ft round above ground pool.  It was empty on Friday when the storm began.  By the following Monday it was full.  That is 42 inches (1.06 m) of rain in 3 days!  Many of my family had evacuated the lower areas of Houston and came here to ride out the storm.  Most hectic and tense as they watched the news to see if their houses were still standing.

The good news is all of my family is ok and will be able to get back on their feet quickly.  The sad news is that 50,000 homes and 1,000,000 cars were damaged or destroyed.  Only 15% of them have National Flood Insurance.  They will be suffering for years.  Please do not forget them 6 months from now.  Most people will get distracted and not remember.

As for the project: I have been working on the design for the pulse stretcher and the pulse height digitizer.  This is the trickiest part of the design.  It is easy to stretch the pulse and then use the longer time constant to allow reasonable A to D conversion.  The hard part for me is to be able to ensure that this process does not alter the overall energy of the pulse so it can be an accurate measurement.

Pulses with picoseconds of rise time and nanoseconds of duration are not easy to simulate or handle (I have no access to the mega-buck software needed).  That means I have to do the math as well as possible and then prototype it and work from there.  For me that is a lengthy process.

Suggestions are welcome.

Stay safe (particularly if you are in a hurricane area).