Constant Current, 1.5 amp, high voltage into variable load
simulate this circuit &ndash; Schematic created using CircuitLab

Figure 1. Detonator circuit.

An overdamped LCR circuit might work for you. This setup, according to my calculations, would raise the current to 1.6 A in 0.2 ms, falling to 1.2 A after 1.5 ms with detonator resistance rising from 80 to 160 ohms.

L1 internal resistance and R1 should sum to 100 ohms. Detonator power dissipation would peak at 500 W, falling to 400 W.

Update

An overdamped RLC circuit (\$ R^2 &gt; \frac {4L}{C} \$) current at time (t) is given by

$$ i(t) = \frac {V_0}{\omega _0L}e^{\frac {-R}{2L}t} sinh~\omega _0t$$

where

$$ \omega _0  = \sqrt {(\frac {R}{2L})^2 - \frac {1}{LC} } $$



I calculated the information here using a spreadsheet and I'm not that confident of my results. I would appreciate if some could post a link for a simulation of the circuit to show if my results look reasonable.