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tokens: current. We have also modified the weighting of the grid points in the velocity domain to check whether models that put less emphasis on small-scale dynamics in the corona could still resolve the bubbles. In all cases, the bubbles created were identical. However, changing the starting atmosphere will change whether a bubble is identified. This is due to the change in the transition region location with respect to the hydrogen column density. The beam will therefore not penetrate at the same location into a different starting atmosphere, which will not trap a portion of the chromosphere. It may very well be that the bubbles can be created in other starting model atmospheres but with a different set of beam parameters. In the example shown in Figure 2 , the initial bubble accelerates upward into the corona initially due to the pressure gradient caused by the beam heating in the chromosphere. However, a shock forms at T = 10 s, which highly accelerates the upper atmosphere, including the bubble. By T = 15 s into the simulation, this velocity is already over 300 km s −1 . The value of temperature, density, and electron density are all stationary within the bubble over time, which is essentially the mass motion of the material. Interestingly, due to the gas pressure increasing at the edges of the bubble, the overall width of the bubble decreases over time. For the bubble in Figure 2 , 45% of the mass is lost between 10 and 15 s due to redistribution of the bubble mass into the overall wave front. This compression can be most easily seen from T = 5 s to T = 10 s in Figure 2 . Individual well-defined bubbles were identified by investigating the temperature of each atmosphere. The location of the transition region was defined to be the lowest point in the atmosphere where the temperature gradient exceeds 5000 K between grid cells, while having a temperature value of at least 50,000 K. Any point above the transition region that has a temperature below 40,000 K was deemed to be a part of the bubble and logged. This resulted in 21/72 atmospheres with bubbles. Of these 21, all had beam fluxes above 1.0e11 erg cm −2 , and low-energy cutoff values above 15 keV. The most common value of low-energy cutoff being E c = 15 keV. This value provides the optimal penetration depth to efficiently trap a portion of the chromosphere while accelerating it upward (see Figure 1 ). The E c = 10 keV models mainly heated the upper chromosphere and some of the transition region, and did not lead to the creation of bubbles. The E c = 25 keV models only resulted in bubbles for the highest spectral indices ( δ > 5) with the highest levels of beam flux (3.0e11 erg cm −2 ). This is due to the extremely high energy density that needs to be applied to the lower chromosphere in order to heat it sufficiently and create a bubble. Harder beams tend to have a larger spread of energy into the denser portions of the photosphere and lower chromosphere. The bubble lifetimes can be as short