ASTM E545 Determining the Image Quality

Scope:

The standard test method ASTM E545 is used to determine quantitative data on neutron beam and image system parameters that influence film exposure and, as a result, image quality. In addition, the Beam Purity Indicator (BPI) is used to check the neutron radiography quality on a day-to-day basis. The BPI is developed and tested using gadolinium conversion screens and single-emulsion silver-halide films exposed together in a neutron imaging beam.

Procedure:

In the ASTM E545 test, a beam of radiation is directed perpendicularly on the film plane. Firstly, a conversion screen is used that responds to neurons of thermal energy; exposure contributors are also calculated. Then, the value of G, H, and sensitivity level is determined. Finally, neutron radiography parameters are determined, and images of wire are compared visually in the BPI.

Data:

Following data is calculated in ASTM E545 testing:

Effective thermal neutron content,
NC =  ( (D_H – (higher D_B + ΔD_L) x ½) x 100
Effective scattered neutron content
S = (∆D_B/D_H) × 100
Effective gamma content,
γ = (D_T – lower D_L)/D_H × 100
Effective pair production content,
P = (∆D_L/D_H) × 100

Conclusion:

The standard test method ASTM E545 is used to determine quantitative data on neutron beam and image system parameters that influence film exposure and, as a result, image quality.