The main factors which affecting the formation and extension of the blue loops of the middle mass stars are studied and the correlation between the feature of blue loops and the variation of the total energy production rate of the star during the core He-burning is found. The variation of the total energy production rate is mainly contributed by the H-burning shell and the core He-burning, the H-burning shell is dependent, however, on the temperature and the hydrogen profile in the μ-gradient region and the inward penetration of the outer convective zone. Both of the size of the He core and the temperature in the region of the He core determine the core He-burning which not only contributes to the total energy production rate, but also has influence on the H-burning shell.
ObjectiveThe effects of field size and asymmetric field on wedge factors are studied.Method The measurment of wedge factors were performed for 60°autowedge of the BJ- 6B linear accelerator for field size from 4 cm×4 cm up to 18 cm×18 cm and asymmetric field.ResultWedge factors had an obvious dependence on the field size, and although dependence on the asymmetric field.ConclusionIn clinical dose calculation, it is sig- nificant to use relative field size wedge factors. It should be adjusted that effect of field size and asymmetric field on wedge factors.
