Philosophy and Ramblings
Many more idle thoughts coming soon....
I thought for a long time about a company logo. A lot of rather feeble designs were considered, along the lines of particles fissioning atoms, gamma ray spectra etc. Winky the Sheep was hit upon as a homage to Blinky, the three-eyed mutant fish that swims in the outfall from Mr Burns's nuke in the Simpsons. Please don't confuse a homage with an homard. One is a French crustacean, the other isn't. Hope you like it. It cost me several notes and was drawn by my lovely daughter.
I've used High Resolution Gamma Spectrometry as an in-situ measurement tool since my first in-situ measurements. It has many technical advantages over Low Resolution Gamma Spectrometry which may not always be obvious.
First, however, the disadvantages: it's expensive - a HRGS system won't give you much change from £25k. It needs cooling, which either means a power supply and an electrical cooler, or liquid nitrogen. LN2 is more portable, and electricity can be a nuisance to find in a field or in a nuclear plant. LN2 is a nuisance if you need to transport it: I used to carry a big dewar around in the boot of my car, butH&S standards have come on since the seventies and the risk (rightly) isn't acceptable by current standards.
LRGS detectors (typically NaI scintillators) come in large sizes: a typical 3"x3" NaI is arbitrarily defined as having 100% efficiency at 1332 keV. By comparison, although high purity germanium (HPGe) detectors are available with large efficiencies, they're very expensive and a typical HPGe detector would only have a relative efficiency of a few tens of percent.
HRGS has a resolution of better than 2 keV at Co-60 energies, nearer 1 keV at Cs-137 energies. LRGS on the other hand has a resolution of around 80 keV at Co-60 energies, and over 40 keV at Cs-137 photopeak.
One might suppose that the higher the resolution, the better, and so LRGS wins when surveying for man-made activity. Unfortunately, it's not quite like that. One needs to consider what might be loosely called "detectability", or more accurately the time needed to reach a certain confidence level in a measurement. Suppose we're looking for the 662 keV peak from Cs-137 in the environment at low levels. There will always be natural background, from cosmic rays and natural radioisotopes (K-40 etc). Around the 662 keV region of the spectrum there will be anatural scattered background in the spectrum.
With a HPGe detector, one can quantify a photopeak with only a few counts in it - say ten to give the software a fighting chance of determining the peak. In a typical survey measurement of a few tens of seconds, thebackground behind the photopeak will be only a couple of counts or so.
Contrast this with a sodium iodide scintillator. Under the same conditions, the greater efficiency might give a peak count of thiry or more counts. However, the background under the peak will be perhaps a hundred or more counts. This makes it much harder to quantify the photopeak, or even to be confident that there is a peak.
These very rough sums show that in the real environment, one can identify and quantify a photopeak much more rapidly and confidently with a HRGS system than with a LRGS system.
I have known many project managers. Project managers are, to the committed geek, a species to be despised and, better still, wound up. The better of them are good actors and can put on an expression of anger or disappointment to order whilst maintaining inner calm. The worst of them just get angry and disappointed.
I have found two good ways to wind up a project manager. The best, and most satisfying, is to tell him that an activity on his critical path is "technically very interesting". A Geek's Interesting Problem is always bad news for a PM. If you are lucky he will give you pots of money to solve the problem, and will look pathetically grateful when you sort it out. If this technique fails, fall back on insulting him: telling him that project managers are just jumped-up admin assistants usually works, for there is an element of truth in it. It helps if you mention it casually, while running a finger over one of the more obscure pages of Abramowitz and Stegun.
I passed the APM exams with quite good marks after being ordered to take the course. This proves nothing about my abilities as a PM, it just shows that I can pass exams. Be warned: do not employ me as a Project Manager as I am easily diverted by interesting problems. On the other hand, I do enjoy Problem Management.
The Big Issue is a magazine sold by homeless people to help them get back into society and to earn an honest crust. Next time you see a Big Issue seller, don't ignore them, just 'kin buy a copy and have a chat with him or her. Got that?
Haiku on Berkeley Active Waste Vaults
Old vaults long-filled
Decayed by decades past