I am building a high power 12V portable Xenon strobe light, and I am trying to make it as bright as possible so I need a few opinions here before I continue designing my circuit.

I am torn whether I should go with a 40mm round flashtube (rated at 100ws, like the one here) or a smaller spiral flashtube (rated at 40ws, like the one here). I am aiming for around 15 Hz (15 flashes per second), so I would be firing the round flashtube at 6.5 joules per flash (for a total of 97.5 joules per second) and I would be firing the spiral flashtube at 2.6 joules per flash (for a total of 39 joules per second).

My question is this: How much brighter would the 40mm round flashtube truly be than the spiral flashtube?

To fire the 40mm round flashtube at 6.5 joules per flash, I will need 144 uF at 300 volts per flash. Will I be able to fill 144 uF of capacitors 15 times per second to successfully fire the round flashtube a full 6.5 joules per flash?

Thank you to everyone for your help and ideas!

 

If you accept the assumption that the bulbs offer the same efficiency in converting energy to visible light, then you've answered your own question. The energy striking the eye of the beholder will be proportional to the energy released. I believe the perception of brightness is more-or-less proportional to the energy received, at least within the narrow range of comparing these two.

The answer to your supply question depends on the nature of your supply. The theoretical answer is "of course" but there are practical considerations. Come on back with a schematic and you'll get plenty of feedback.