## 4 Results and Discussion
### Influence of Changing Plasma Power on the Dust Particle Size and Dust Density  
In the previous sections, we have introduced the method of determining the dust particle radius and the dust density from the measurement of the free electron density and the laser light extinction. In this section, we will continue by investigating the behavior of the dust particle radius and dust density as a function of plasma power. In these experiments, the partial pressures of argon and HMDSO are similar to those described in Section 3.1, while the power is varied from 8 W to 23 W. In line with the reasoning presented in Section 4.1 we selected the point in time right before the formation of the void, which coincides with the turning point in the transmittance (see Figure 3b). At this point, the dust particle radius and the dust density were recorded and plotted in Figure 8, both as a function of plasma power. In this Figure, the error bars arise from the propagation of  
Figure 7: Sensitivity analysis for the negative ion density. Using the same raw data set, the dust particle radius (shown in panel (**a**)) and dust density (shown in panel (**b**)) are determined for negative ion densities ranging between \(n_{\text{i-}}=2\)-\(8n_{\text{e,initial}}\), while a constant value of the electron temperature \(T_{\text{e}}=3\) eV is assumed.  
errors in the measured electron density \(\hat{n}_{\mathrm{e}}\) and the transmittance \(\hat{T}\), which via the fitting procedure results in errors in the estimated \(a\) and \(n_{\mathrm{d}}\). In order to guide the eye, polynomial fits are included through the data points.  
Figure 8 shows that by increasing the plasma power, the determined dust particle radius decreases while the dust density increases. By increasing the plasma power, (i) the overall plasma densities increase, while (ii) the growth cycle time decreases. For both effects, we will hypothesize about what happens to the resulting dust particle size \(a\) during the accretion phase. An increase in the plasma densities will increase the ion/radical fluxes towards the particle, leading to faster particle growth. The decreasing growth cycle time is a direct result of a change in the force balance acting on the particles. By increasing the plasma power, both the densities and the electric field strength increase, which eventually causes the ion drag force to be able to overcome the electrostatic force at shorter timescales [36]. This leads to a shorter growth cycle, which translates to a shorter residence time of the dust particles in the plasma and eventually leads to smaller dust particles.  
From the previous discussion, the two mentioned effects counteract each other. In our previous work [36] it was argued that using the transmittance \(\hat{T}\) enabled measuring only the combined quantity \(a^{2}n_{\mathrm{d}}\), which made it difficult to differentiate between effects in the dust particle size and the dust density. However, using the newly developed method, Figure 8 shows that we are able to disentangle the behavior of the dust particle size and density evolution. This indicates that for higher plasma power, the effect of the shorter growth cycle leads to smaller dust particles, even though the fluxes towards the dust particles' surfaces are larger.