Development and application of cobalt source layout interface program for gamma irradiation device

Fig. 2. Product space dosimeter distribution grid (a) and source rack surface dosimeter distribution grid (b)

Fig. 3. Manual layout design process for cobalt sources

Fig. 4. Cobalt source manual layout operation interface

Fig. 5. Automatic layout design process for cobalt sources

Fig. 6. Cobalt source automatic layout effect calculation interface

Fig. 7. Software generated GEANT4 program executable macro file (partial display)

Fig. 8. Cobalt source manual layout effect calculation interface

Fig. 9. Comparison of cobalt source layout interface program with GEANT4 and experimental testing of dose distribution on vertical of product

Fig. 10. Experimental gamma irradiator source frame structure diagram

Fig. 11. Effect diagram of cobalt source concentrated and dispersed layout (color online)

Table 1. Comparison of cobalt source layout interface program with GEANT4 and experimental testing

Table 1. Comparison of cobalt source layout interface program with GEANT4 and experimental testing

BFT-II伽玛装置（1.13×10¹⁷ Bq） BFT-II gamma rrradiator（1.13×10¹⁷ Bq）	剂量不均匀度 Dose uniformity ratio	钴源利用率 / % Cobalt $u t i l i z a t i o n$ efficiency	产能（3.7×10¹⁶ Bq, 0.1 g/cm³, 25 kGy, m³/h） Production capacity （3.7×10¹⁶ Bq, 0.1 g/cm³, 25 kGy, m³/h）
Cobalt_OS（A）	1.24	20.53	4.38
GEANT4（B）	1.36	19.94	4.03
实验测试结果（C） Experiment result(C)	1.31	19.90	4.24
相对偏差1（A-B）×100%/B Relative deviation 1（A-B）×100%/B	-8.8%	3.0	8.7%
相对偏差2（A-C）×100%/C Relative Deviation 2（A-C）×100%/C	-5.3%	3.2	3.3%

Table 2. Distribution proportion of gamma irradiator source module by concentrated layout

Table 2. Distribution proportion of gamma irradiator source module by concentrated layout

装置活度 / Bq Irradiator activity	集中排布Concentrated layout
装置活度 / Bq Irradiator activity	横向模块比例 / % Horizontal module proportion	纵向模块比例 / % Vertical module proportion
3.48×10¹⁶	13.1∶36.8∶36.9∶13.2	0.0∶0.0∶19.7∶29.8∶30.9∶19.6∶0.0∶0.0
7.25×10¹⁶	11.4∶38.6∶38.6∶11.4	0.0∶0.0∶16.0∶34.6∶35.7∶13.7∶0.0∶0.0
1.13×10¹⁷	14.3∶35.7∶35.7∶14.3	0.0∶0.0∶20.7∶29.3∶29.3∶20.7∶0.0∶0.0

Table 3. Distribution proportion of gamma irradiator source module by dispersed layout

Table 3. Distribution proportion of gamma irradiator source module by dispersed layout

装置活度 / Bq Irradiator activity	分散排布 Dispersed layout
装置活度 / Bq Irradiator activity	横向模块比例 / % Horizontal module proportion	纵向模块比例 / % Vertical module proportion
3.48×10¹⁶	22.9∶31.6∶16.5∶29.0	12.5∶12.2∶13.7∶18.5∶17.8∶10.4∶9.7∶5.2
7.25×10¹⁶	20.2∶28.1∶27.1∶24.6	12.8∶10.8∶13.5∶13.4∶13.8∶12.1∶10.8∶12.8
1.13×10¹⁷	22.8∶28.2∶25.8∶23.2	12.5∶12.4∶13.0∶14.5∶12.5∶12.2∶11.0∶11.9

Table 4. Calculation and analysis of production capacity for concentrated and dispersed layout of cobalt sources of different activities

Table 4. Calculation and analysis of production capacity for concentrated and dispersed layout of cobalt sources of different activities

测试活度 / Bq Test activity	集中排布-产能（3.7×10¹⁶ Bq, 0.1 g/cm³, 25 kGy, m³/h） Concentrated layout-production capacity （3.7×10¹⁶ Bq, 0.1 g/cm³, 25 kGy, m³/h）			分散排布-产能（3.7×10¹⁶ Bq, 0.1 g/cm³, 25 kGy, m³/h） Dispersed layout-production capacity （3.7×10¹⁶ Bq, 0.1 g/cm³, 25 kGy, m³/h）
测试活度 / Bq Test activity	Cobalt_OS（A）	GEANT4（B）	相对偏差 / % Relative deviation (A-B)×100%/B	Cobalt_OS（A）	GEANT4（B）	相对偏差 / % Relative deviation (A-B)×100%/B
3.48×10¹⁶	4.01	3.74	7.2	3.86	3.54	9.0
7.25×10¹⁶	4.17	3.86	8.0	4.03	3.74	7.8
1.13×10¹⁷	4.38	4.03	8.7	3.93	3.87	1.6

Table 5. Calculation and analysis of utilization efficiency for concentrated and dispersed layout of cobalt sources of different activities

Table 5. Calculation and analysis of utilization efficiency for concentrated and dispersed layout of cobalt sources of different activities

测试活度 / Bq Test activity	集中排布-利用率 / % Concentrated layout- $u t i l i z a t i o n$ efficiency			分散排布-利用率 / % Dispersed layout- $u t i l i z a t i o n$ efficiency
测试活度 / Bq Test activity	Cobalt_OS（A）	GEANT4（B）	相对偏差 / % Relative deviation (A-B)×100%/B	Cobalt_OS（A）	GEANT4（B）	相对偏差 / % Relative deviation (A-B)×100%/B
3.48×10¹⁶	20.67	19.73	4.8	18.54	17.70	4.7
7.25×10¹⁶	20.93	19.71	6.2	18.88	17.94	5.2
1.13×10¹⁷	20.53	19.94	3.0	18.32	18.04	1.6

Table 6. Calculation and analysis of dose uniformity ratio for concentrated and dispersed layout of cobalt sources of different activities