The phrase "an initial radiation" is correct and usable in written English.
It can be used in contexts related to physics, medical imaging, or any field discussing the first instance of radiation emitted or detected.
Example: "The study focused on an initial radiation emitted during the first moments of the experiment."
Alternatives: "a preliminary radiation" or "an early radiation".
Intrinsic molecular radiosensitivity was measured by using an initial radiation-induced DNA damage assay on lymphocytes obtained from breast cancer patients before radiotherapy.
A fast initial radiation at the time of colonization of the terrestrial habitat by the ancestors of modern streptophyte algae as proposed by Stebbins and Hill [ 41] may also explain the relative difficulty to infer the phylogenetic relationships among the four groups of streptophyte algae, enhanced by the accelerated evolutionary rate of the Zygnematales.
Five of them belong to the basal branches of the Caprinae tree, thus supporting the hypothesis of a very fast initial radiation of this group.
It is likely that the lack of resolution in the basal branches is due to the existence of a very quick initial radiation in the Caprinae subfamily.
Divergence dates from the multilocus concatenated analysis suggests a relatively synchronous initial radiation of the four major clades in Melanohalea with mean diversification times occurring between 14.9 – 17.2 Ma, with no clear temporal pattern in subsequent diversification events.
This truly supports the existence of a quite fast initial radiation that led to the differentiation of nine clades (including the Myotragus lineage) that are at the base of all extant genera.
The purpose of this study was to evaluate dose response relationships for the in vivo induction of micronuclei (MN) as a measure of both initial radiation damage and the induction of genomic instability.
5, 20 Buscariollo et al 20 (2012) reported on 144 ATRT patients in a retrospective study and noted that those who received initial radiation therapy had a better overall survival when compared to those who did not (34 months to not yet reached vs 6 months, P<0.001).
Several authors have illustrated examples of increasing ammonoid shell size during initial radiation of a group [ 46, 129, 133, 134].
