5.5.1                 Uncertainties associated with EEE component radiation susceptibility data

a.              It shall be demonstrated that the achieved RDM includes the uncertainties that arise in component susceptibility data from the radiation hardness assurance programme specified in ECSS-Q-ST-60 for Class 1, 2 and 3 components, including:

1.              uncertainties in the results from irradiation: the beam characterization and dosimetry, and the subsequent statistical errors in the measured or derived results such as SEE cross-sections;

2.              differences between the test circuit and the application circuit, such as bias conditions, opportunities for annealing or ELDRS;

3.              differences in the radiation susceptibility of different components within the same batch, or within the collection of batches selected for testing;

4.              differences between part batches or collection of batches, where errors arise from relating the results from component irradiations to devices employed in the final application;

5.              the possible effects of packaging on low-energy proton beams (<30 MeV);

NOTE              The reason is that this packaging can affect the penetration and energy (LET) of the particles.

6.              the stated accuracy of the facility together with the uncertainties in requirement 5.5.1a.1, taking into account position, attenuation;

NOTE 1      In the absence of contemporaneous beam characterisation, quoted particle accelerator characteristics are assumed to be no better than ±30 % accurate in beam intensity.

NOTE 2      For g-ray sources such as 60Co, uncertainties in the total ionising dose delivered are typically better than ±10 %.

7.              the variations in performance within a device population, be determined by employing one or more of the following and in accordance with the radiation hardness assurance programme defined according to ECSS-Q-ST-60 for Class 1, 2 and 3 components:

(a)            statistical techniques applied to test data;

(b)           data from heritage information concerning the part;

(c)            data from previous worst case analyses.

NOTE              Such techniques are defined in the clauses of ECSS-Q-ST-60 relevant to “Radiation Hardness”.