Harwell Radspin

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Harwell Radspin 2017-06-21T09:30:11+00:00

When pellets containing the amino acid alanine are irradiated, stable free radicals are produced in a concentration which depends on exposure.

The measured response to microwaves of the pellet placed in a magnetic field of a paramagnetic resonance spectrometer, is quantitatively related to the radiation dose which the pellet absorbed.

Dose Range

Radspin has a functional dose range of 0.1 kGy to 70 kGy (0.01 kGy to 100kGy may also be achieved) which makes it ideal for almost any range of irradiation processes.


A white cylindrical pellet of alanine in a wax binder.

90.9% Amino acid L-alpha alanine

9.1% Paraffin wax


Diameter: 4.82mm +/- 0.01mm (5mm to special order)

Height: 2.8mm +/- 0.1mm

Mass: 60mg +/- 2mg within the overall batch, +/- 0.6mg within a lot. (standard deviation 0.3mg)


Two Formats:

Plain Pellets, bulk packed

Radspin Dosimeters, consisting of pellets sealed in bar coded labelled aluminium foil blisters, packed 1,000 per carton.

Measurement Reproducibility

Mass: CV 0.5%

Irradiation response: CV 0.5% NPL irradiated. (not packed)


Each batch is verified by NPL comparision.


Eight years from the date of release.