Code for laser ablation of material

Hi, so basically I'm not great with matlab but I need to use it for a project I have; I'm writing a script to calculate the number of laser pulses required to change the velocity of a small block floating in space and I need to create a loop to account for the reduction in mass of the block with each laser pulse that strikes it. I know the initial mass and the change in velocity required but not the final mass, I have equations for the amount the mass reduces by with each laser strike, the velocity change with each strike and I know the desired velocity change. So basically what I want to know is how can I create a loop (or whatever method works best) to feed the new mass into the velocity change equation and finish when the velocity change reaches a set value.

TIA

Answer 1

[Walter Roberson]

Something like

initialize mass
initialize velocity
while velocity < target
    decrease mass
    increase velocity by force / mass
end

It is, though, fair to ask about the timing of the increase in velocity versus decrease in mass. Can the pulse be treated and removal of mass be treated as instantaneous, or is it necessary to model the fact that energy is arriving over time and there is more mass to distribute it over at the beginning of the pulse than at the end of the pulse.

Is the mass that is vaporized going to travel in the same direction and at the velocity it had at time of vaporization, but as a gas? As a plasma? Does it cool down and reappear as a solid? As long as it continues to exist then unless it moves to the side, it is going to be in the path of the pulse and so might be acted upon by the pulse, potentially to the point where the pulses end up heating the plasma but no longer reaching the block. Does the abalated mass somehow jet away from the block, and by action/reaction thereby increase the velocity of the block? Is that possibly even the primary propelant system, rather than the photon energy delivered into the block ?