低エネルギーX線によるタマネギおよびジャガイモ発芽防止のための効果的照射方法

Abstract

The sprout inhibition of onion and potato by low energy X-rays was investigated using a 160 kV X-ray irradiation system to determine optimal irradiation conditions. The sprouting of onion was effectively suppressed by irradiating 20 Gy at a depth of 3.2 mm from root side for small onion and at 8.0 mm depth for large onion, respectively. For potato, double-sided irradiation was necessary to irradiate the entire potato because the buds were distributed throughout the entire potato. Irradiation on double-sided at a depth of 8.0 mm with 50 Gy (60 Gy at 5.4 mm) effectively inhibited the sprouting. The throughput calculated to be 80.9 kg/h for large onion, 34.1 kg/h for small onion, and 9.9 kg/h for potato at a distance of 350 mm from the focal point of source. Dose uniformity (Dmax at surface/Dmin at 8.0 mm depth) of potato in case of double-sided irradiation was improved from 3.6 (182 Gy/50 Gy) to 1.2 (58 Gy/50 Gy) by using an aluminum 1.0 mm filter (F1) to cut off low energy X-rays, whereas the throughput capacity decreased from 9.9 kg/h to 7.4 kg/h.