1. Efficiency correction of 2D-Large PSD by C language Jong-kyu Cheon Radiation Physics Lab.

2. contents Introduction Simple theory Algorithm Experiment C Programming Result Conclusion

3. Introduction Large PSD In 2003, KAERI fabricate Large PSD for Small Angle Neutron Scattering. Uniformity test Small non-uniform area it need Efficiency correction.

4. Simple theory e : efficiency correction coefficient n : count n : mean of counts

5. Algorithm White beam 2d-data mean of counts Efficiency matrix(e ij ) Apply efficiency matrix to data matrix Correction data

6. Experiment Sample : plexyglas Exp.time : 1 hour x 9 Resolution : 256x256 Effective area : X : 8 - 244 channel Y : 13 - 240 channel (228 × 237 = 54036 pixel)

7. C Programming for(j=0; j < 256; j++){ for(i=0; i < 256; i++){ if ( i > 12 && i 7 && j < 245 ) { eff[i][j] = (double) 11939.42/(double)select[i][j]; } center

8. Result

9. Low count error

10. Conclusion Efficiency correction is useful in non-uniform data. Need to consider low count data