Four pi arrays
From GOSIA
(creation) |
(Added notes on absolute efficiency and normalization to Rutherford) |
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See the manual entries on OP,GDET and "Gamma Detector Solid Angle Attenuation Factors" for more information on these attenuation coefficients. | See the manual entries on OP,GDET and "Gamma Detector Solid Angle Attenuation Factors" for more information on these attenuation coefficients. | ||
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+ | The accuracy of this calculation depends on the uniformity of the array's acceptance over <math>\theta, \phi</math> polar and azimuthal angles. For example, the largest gap in coverage in Gammasphere is near <math>\theta=0</math>, <math>\phi=0</math>. If this non-uniformity does not have a significant influence on the accuracy, then the technique above using the angular attenuation coefficients can be used. | ||
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+ | Approximately uniform gaps in the acceptance of the Ge array can be absorbed into the overall absolute efficiency of the array. Since Gosia fits to ''relative'' <math>\gamma</math>-ray yield data, the absolute efficiency has no influence on the "typical" calculations. (See the page on [[normalizing_to_the_rutherford_cross_section | normalizing to the Rutherford cross section]]. This technique requires special considerations. |