  We demonstrate a controllable depletion of the nitrogen buffer gas pressure
in a micro-machined cesium (Cs) vapor cell from the dynamic heating of an
alkali dispenser pill. When the alkali source is laser activated, the gettering
compounds within the alkali pill dispenser reduce the nitrogen (N$_2$) content
from the vapor for fine-tuning of the alkali to buffer gas pressure ratio.
Additionally, we decrease the buffer gas pressure below 100$\,$mTorr to
evaluate the presence of other potential broadening mechanisms. Real-time
control of the gas pressure ratio in the vapor cell will have notable benefits
for refining atomic sensor performance and provide a routine to achieve various
target pressures across a wafer bonded with a uniform back-filled buffer gas
pressure.
