Fig. 4
Sub-critical approach to the divergence of CP-1. We display the inverse of the amplification factor as a function of the number i of completed layers: experimental data (blue squares) correspond to the quantity \(i/A_i\), where \(A_i\) is the detector response reported in Ref. 21, Table 1 (the value \(A_{41}=350\) in the report was clearly a typo and should read \(A_{41}=846\), or possibly \(A_{41}=850\), based on the available data). The values computed with tripoli-4 (red circles) correspond to \(1-k_\text {eff}\). The tripoli-4 curve has been normalized to match the experimental values at layer 54. Values for layers beyond 54 were not provided in Ref. 21; CP-1 went slightly supercritical at layer 57.
