Echo detected EPR as a tool for detecting radiation-induced defect signals in pottery

Archaeological fragments of pottery have been investigated by using CW-EPR and Echo Detected EPR (EDEPR). EDEPR allows to remove the CW-EPR dominant Fe(III) background spectrum, hiding much weaker signals potentially useful for dating purpose. EDEPR spectra attributed to a methyl radical and to feldspar defects have been recorded at room and low temperature for an Iron Age cooking ware (700 B.C.). A study on the dependence of EDEPR intensity over absorbed dose on a series of γ-irradiated brick samples (estimated age of 562 ± 140 B.C.) has confirmed the potential efficacy of the proposed method for spotting defect signals out of the strong iron background.

► Fe(III) CW-EPR signals cover CW-EPR-detectable defects in ceramics.
► Echo detected EPR gets rid of Fe(III) signals, disclosing defect signals.
►  Echo detected EPR detects defect signals even at relatively low doses.