icon Kapiti gaigakaunta

icon latest

29Jun2017 10:32
http://zl2tod.net/gaigakaunta
http://zl2tod.net/gaigakaunta
http://zl2tod.net/gaigakaunta
http://zl2tod.net/gaigakaunta
Extreme peaks and troughs are from faults or are artifacts of me fiddling with the equipment.
spectrum
Latest spectrum 24Aug2011

icon twin peaks

2 Dec 2012
Once again a disturbed airstream from the North West has brought readings higher than this station has yet recorded.
alt
Radio New Zealand reported thunderstorms in Wellington overnight which persisted longer than the Metservice weather forecasters could remember.
animated satellite photos with lightning overlaid

icon index

icontwin peaks - highest levels yet
2 Dec 2012
iconlatest - most recent data here
29Jun2017 10:32
iconreview - up to date
26 May 2012
iconAm241 v2.0 - smoke alarm redux: hot
28 April 2011
iconAm241 - smoke alarm false start
22 April 2011
iconbias - increased voltage from 478 to 725V
21 April 2011
iconprejudice - snapshot of record before voltage increase
21 April 2011
iconperspective - tritium in local waterways
21 April 2011
iconspectra - gallery of spectra 30Mar-17Apr
17 April 2011
iconfall - southerlies eat radiation
5 April 2011
icontop model - Norwegian atmospheric projector
5 April 2011
iconrain - it's hot up north
27 March 2011
iconbulk bins - fiddling with PRA
25 March 2011
iconlinks
24 March 2011
iconproduction - just another plot of background
24 March 2011
icondimension++ - first 10½ hour run
23 March 2011
iconforth - a better regulator, discovering PRA
22 March 2011
iconthe third day - looking at pulses
21 March 2011
icontutu - rock is cold
20 March 2011
iconguff - te ahi kaa
19 March 2011
Kapiti, New Zealand

icon guff

19 March 2011
This is a scintillation detector sitting on a workbench on the Kapiti coast north of Wellington, New Zealand.
It consists of an NaI(Tl) (Thallium doped Sodium Iodide) crystal, I kid you not, under a tinfoil hat. When ionising radiation hits the crystal, scintillation, flashes of light, happens. The crystal peak emission wavelength is 430nm ("super blue").
This is faced up against a photomultiplier tube to complete the detector.
A power supply and interface came with the detector. This runs on 24VDC and generates the high voltage for the photomultiplier. The various electrodes in the photomultiplier tube are connected to a resistive divider in the power supply. A BNC connector carries the electrical output pulses.
These pulses are tee-ed off to a sound card line in, which is used for spectrographic analysis, and to a buffer and an RS232 driver which is used to make the Counts Per Minute graphs.
This all makes a highly sensitive, somewhat unstable, γ (gamma) ray detector capable of broadband spectrographic operation, with peak sensitivity around 210 keV.
Gamma rays have energies of 124 keV or more.
Uncalibrated and subject to change.
Kia kaha Christchurch.
Kia kaha Japan.
Kia kaha katoa.