Given very poor fit using line + power law + line, changes were made to the fitting algorithm.
- Starting paramters optimised for new typical wave shape
- Reverted to 3 lines, since signals are faster
- Subtracted wave minimum from all wave points to have a more realistic chi2 estimate
- Discarded all waves where 2nd half of signal > 1st half of signal. Should correspond to pick-up / noise

Fit: 3 lines
Free parameters: 2x boundary points between lines
Algorithm: Nelder-Mead, 20 iterations.

Attach 1: Wave amplitudes
Attach 2: Rise times
No major differences vs. power law method, but note candidate electron peak in rise time spectrum is now sharper.

Attach 3-9: Waveforms with H~90 and increasing rise times. 
Note fit shown are via Solver's GRG, not NM.
Fits in waves 1-4 give same result for GRG and NM.

Fit in wave 5: NM-> H72 t102 vs. GRG-> H80 t25
Fit in wave 6: NM-> H96 t128  vs. GRG-> H90 t23 
GRG risetimes are more realistic. This appears to be due to very short baseline pre-rise.
Will increase in next run.

Fit in wave 7 is rare pile-up event. Code cannot yet cope. Bad fit.