Illumination

In Strickland's paper, it's mentioned that they used 8000 mcd LEDs from [http://www.theledlight.com theledlight.com], with 20º viewing angle and 468 nm at 3.4 V.

It's also mentioned that a single LED was used per tube, with a cross section of 0.12 cm² = 1.2x10^-5 m².

20º viewing angle, 0.35 rad, means a solid angle of 2π(1-cos(0.35)) = 0.381 sr.

This gives a luminous flux of 0.381*8 = 3.05 lm per LED.

The illuminance they used was then 3.05/1.2x10^-5 = 2.54x10⁵ lux (or lm/ m²).

A bioreactor that has some 0.2*π*0.3 = 0.19 m², we would need at least 2.54x10⁵ * 0.19 = 48260 lm, or some 16000 LEDs just to make sure the outer surface of the bioreactor has the same light conditions!!

This doesn't take into account reflections in the bioreactor, so I hope it will lower this number.