The Noise Performance of Electron Multiplying Charge-Coupled Devices at soft X-ray energies

The use of EM-CCDs for high resolution soft Xray spectroscopy has been proposed in previous studies and the analysis that followed identified and verified experimentally a Modified Fano Factor for X-ray detection using an Fe X-ray source. However, further experiments with soft X-rays at 1000 eV were less successful, attributed to excessive split events. More recently, through the use of a deep depletion e2v CCD220 and on-chip binning, it was possible to greatly reduce the number of split events allowing the result for the Modified Fano Factor at soft X-ray energies to be verified. This paper looks at the earlier attempt to verify the Modified Fano Factor at 1000 eV with a e2v CCD97 and shows the issues created by the splitting of the charge cloud between pixels. It then compares these earlier results with new data collected using the e2v CCD220, investigating how split event reduction allows the Modified Fano Factor to be verified for low energy X-rays.