The floodlight was designed to function at a singular power setting. Therefore, both the experiments and simulations adhered to this specific power input, resulting in a simulated photon flux received of 12.5 μmol s -1 (~4.1 W optical power received by the reaction mixture). Figure showcases the kinetic curves at different rotor rotation speeds, along with their corresponding fits. Unlike the microcapillary reactor, the molar balance for the pRS-SDR was developed under the presumption that the reactor emulates the behavior of a continuously stirred tank reactor (CSTR). This presumption is grounded in our previous studies which indicate that CSTR behavior prevails under standard pRS-SDR operation (Supplementary Information). From the experimental data, it is evident that the rotor's rotation speed has a minimal impact on the reaction rate. This suggests that the system operates not in a mass-transfer limited domain, but predominantly within a photon-limited regime. The projected geometric average path length for this reactor was estimated at the axial gap distance (i.e., the spacing between the quartz stator and rotor), which is 2.0 mm. Based on this value, an initial photon absorption rate of approximately ~0.78 can be derived. all light gets absorbed, the maximum flux through integration of the radiometric intensity, the simulated flux through raytracing simulations, and the fitted flux using the geometric average path length. C) The experimental data and kinetic curves for the investigated pRS-SDR system, showing the non-converted fraction 1 -𝑋𝑋 of starting material as a function of residence time 𝜏𝜏, for their effective optical path lengths (average of 𝑙𝑙 ̅ = 5.3 mm) and the geometric average path length ⟨𝑙𝑙⟩= 2.0 mm. d) The experimental pRS-SDR setup. The simulation in a) was done for a power input of 175 W, using 20 LEDs with 1.5•10 3 photons each, 2.4•10 4 of those interacting with the reaction mixture, with only a selection of 1•10 3 of those shown for visualization.