Radon measurement with DIY track detectors

Radon: origin, health effects, measurements, Marco Silari, CERN:



Playing with Radioaktiviät - cool.

Alpha particles form the gas or liquid shoot holes in the plastic, then you develop it to make the hole bigger. Take CR-39 Plastic (from laser googles ?) etch it with 7M NaOH, 70°C for 5h ?

1 M NaOH is 40g

NaOH is commonly used to develop photo-resist when making DIY printed circuit boards... so we should have some in the lab.

PMMA/Acryl should work as well...

Can we use the DVD laser scanner to see the holes?

And could we use a DVD as detector material (Polycarbonat)? And how about modifying a DVD player to read the holes? And using old CDs or DVDs from a cellar to determine the radon concentration? Make it a community science project?

People have looked into this before: Application of polystyrene films for indoor radon dosimetry as SSNTD

Radon mapping by retrospective measurements – an approach based on CDs/DVDs

echt geil

How about Electrochemical etching or Ultrasonic etching?

First Experiments
Let's try and meet at SDG Solution Space in Geneva for "Open Hackuarium 228 "Sans les murs" #2, Spécial Genève"





Hmm... did not work. No traces.

Second Experiment
Let's try again.

Maybe we need to use ultrasonic bath or electrochemical etching?

Electrochemical etching with 15 kV AC/cm, 40 kHz.

Electrochemical etching studies of the CR-39 plastic



Getting the CR39 from ebay, it's cheap. (Look for "CR39 welding")



Put a piece of CR39 and a piece of delaminated DVD-R on an alpha source (Quantum Pendant), then 2 hours in 7M NaOh in an ultrasonic bath a 70-80°C.

The source produces about 2-5 big alpha impacts per cm2 per second.

And there seems to be something. One side of the plastic sample turned milky. The other side that was covered by a scotch tape during radiation (not during the etching) is clean.



DVD sample and CR39 sample

Inspecting the samples under the microscope. There are holes or bumps in different densities and with a size of about 3um of diameter.



DVD sample and CR39 sample under the web cam microscope. (400x)

Tried to look at the samples with the DVD scanning microscope. Looks nice:



Links:

Measurement of Radon Gas Concentrations in Tap Water for Baghdad Governorate by Using Nuclear Track Detector (CR-39)