The plant transfer factor of natural radionuclides and the soil radiation hazard of some crops.

In the present study, the transfer factors of the natural radionuclides 238U, 232Th, and 40K were estimated for several crops cultivated in farms in the suburbs of Baghdad and one farm in Al-Najaf. The transfer factor (TF) is the ratio of activity transfers from soil to plant. The specific activities of the natural radionuclides were measured with a gamma-ray spectrometer with a HPGe detector. The crops include cereals (rice and wheat), fruits (lemons and oranges), podded vegetables (vigna and okra), fruity vegetables (chili peppers and Solanum melongena), and leafy vegetables (Apium graveolens, Raphanus sativus, and Ocimum basilicum). The results showed that the highest transfer factors for 238U, 232Th, and 40K are 0.32, 0.70, and 3.44, respectively, in wheat. The average transfer factors for 238U and 232Th were founded 0.23 and 0.2 which are lower than the default unitiy value but the 1.85 were reported for 40K higher than unity.

Investigation of the favorable etching time of CN-85 nuclear track detector.

The favorable etching time of alpha tracks registered in CN-85 solid-state nuclear track detector was explored by chemical etching heated by three different techniques: the classical water bath, unconventional microwave, and ultrasound techniques. The parameters that affect the etching of the tracks, namely the rate of bulk etching (VB), the rate of track etching (VT), the ratio of track etching (V), the critical angle (θc), and the registration efficiency (η), were determined. The favorable etching times to develop the highest number of registered tracks in CN-85 irradiated with alpha particles emanated from a 241Am source was found to be 30, 10, and 20min for water bath, microwave, and ultrasound heating techniques, respectively. The obtained results showed the track density possesses the highest value when the detector was etched by different heating techniques: ultrasound, water bath, and microwave heating technique respectively. As well as, the etching time was faster when the etching was done by microwave, ultrasound, and water bath. Moreover the results might also showed that the etching parameters (except ƟC) are maximum with using microwave, ultrasound, and microwave, respectively.