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I want to ask about the differences between a photon rocket and a rocket which uses conventional propellant.

A conventional rocket shoots exhaust matter out the back end, resulting in impulse and acceleration.

A photon rocket shoots photons out the back end, resulting in impulse and acceleration.

The exhaust propellant of a conventional rocket transfers some of its momentum to the rocket, which results in the impulse and acceleration for the rocket. This leaves the exhaust propellant particles with lower

The photon exhaust of a photon rocket transfers some of its momentum to the rocket, which results in the impulse and acceleration for the rocket. This leaves the photon exhaust particles with lower

A conventional rocket can incorporate an expansion nozzle and bell to drain/transfer even more momentum from the propellant exhaust particles to the rocket than would have otherwise been possible without the nozzle and bell, thus resulting in a more efficient rocket. This happens because the expansion nozzle and bell provide more collision opportunities for the exhaust propellant particles to transfer momentum to the rocket.

What is the analogous counterpart to the nozzle and bell, for a photon rocket? Is there anything?

A conventional rocket shoots exhaust matter out the back end, resulting in impulse and acceleration.

A photon rocket shoots photons out the back end, resulting in impulse and acceleration.

The exhaust propellant of a conventional rocket transfers some of its momentum to the rocket, which results in the impulse and acceleration for the rocket. This leaves the exhaust propellant particles with lower

*velocity*(energy) than they otherwise would have left with.The photon exhaust of a photon rocket transfers some of its momentum to the rocket, which results in the impulse and acceleration for the rocket. This leaves the photon exhaust particles with lower

*frequency*(energy) than they otherwise would have left with.A conventional rocket can incorporate an expansion nozzle and bell to drain/transfer even more momentum from the propellant exhaust particles to the rocket than would have otherwise been possible without the nozzle and bell, thus resulting in a more efficient rocket. This happens because the expansion nozzle and bell provide more collision opportunities for the exhaust propellant particles to transfer momentum to the rocket.

What is the analogous counterpart to the nozzle and bell, for a photon rocket? Is there anything?

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