Effect of Li-7 (45 MeV) ions on spinach leaves studied by thermoluminescence technique

In the present work, we have studied the effect of different fluences of Li -7 (45 MeV) (10(4)-5 x 10(7) particles/cm(2)) on the photosynthetic apparat us of spinach (Spinacia oleracia L.) leaves using the thermoluminescence (T L) technique. Fitting of the recorded TL glow curves using the general orde r kinetics theory for the control sample showed the presence of the standar d TL bands i.e. A(I), D(II), Q(III), B(IV) and C(V) at around -20 degrees C , -5 degrees C, 10 degrees C, 30 degrees C and 50 degrees C respectively. T he irradiation with fluence of 10(4) particles/cm(2) resulted in the induct ion of a new TL band at around 16 degrees C along with the other bands, whi le the sample irradiated with 10(5) particles/cm(2) showed a splitting of t he B band into its components B-1 (20 degrees C) and B-2 (30 degrees C) in addition to the new band. On irradiation with 5 x 10(7) particles/cm(2), an apparent shift of all the bands towards the lower temperature side was obs erved. These findings suggest that exposure to Li-7 (45 MeV) ions results i n an alteration of the characteristic trap distribution which represents th e energy levels of the various electron transport components within the pho tosynthetic apparatus. (C) 1999 Elsevier Science B.V. All rights reserved.