LET effects following neutron irradiation of lithium formate EPR dosimeters

The energy dependence of lithium formate and alanine EPR dosimeters for medium energy x rays

“…Malinen et al 41 observed an increase in the EPR resonance line width of the lithium formate exposed to neutrons of high LET compared to ␥-rays. In this work, as LET effects were indicated by a relative effectiveness below unity, the line widths of irradiated lithium formate were measured ͑data not shown͒.…”

Potassium dithionate EPR dosimetry for determination of absorbed dose and LET distributions in different radiation qualities

“…Without using sophisticated methods like those described by Malinen et al (2006) and Waldeland et al (2010b) differences in line width in EPR spectra from samples irradiated with different beam qualities were not detectable. This might be explained by the fact that the increase in line width due to higher ionisation density is small.…”

“…inhomogeneous broadened EPR signals. In literature it has been reported that lithium formate irradiated with neutrons (Malinen et al 2006) and protons and nitrogen ions (Waldeland et al 2010b) have a slightly increased line width as compared to samples irradiated with photons. Rakvin et al (2007) observed a change in Tm using pulsed EPR methods in alanine irradiated with different ions as compared to photon irradiated samples.…”

“…The increased temperature expected in the heavy charged particle tracks (Norman (1967)) might induce changes in the relative amounts of radicals in irradiated alanine, detected as slight changes in the relative ratio of EPR lines in the alanine spectra. However, as pointed out by Malinen et al (2006), the underlying mechanisms need to be further studied.…”

“…They found experimental evidence that the radical distributions are indeed dependent on radiation LET. Several investigators (Ciesielski and Wielopolski (1994), Ciesielski et al (1998), Malinen et al (2006)) report changes in the power saturation properties of material irradiated with high LET as compared to photon irradiated samples indicating that high-LET irradiation may alter the crystal lattice and therefore the spin-lattice relaxation time T1.…”