[en] Rate coefficients for the excitation of the 4.3-μm bands of CO₂ by low-energy electrons in CO₂ have been measured using a drift-tube technique. The CO₂ density [(1.5 to 7) x 10¹⁷ molecules/cm³] was chosen to maximize the radiation reaching the detector. Line-by-line transmission calculations were used to take into account the absorption of 4.3-μm radiation. A small fraction of the approximately 10^-8 W of the 4.3-μm radiation produced by the approximately 10^-7-A electron current was incident on an InSb photovoltaic detector. The detector calibration and absorption calculations were checked by measuring the readily calculated excitation coefficients for vibrational excitation of N₂ containing a small concentration of CO₂. For pure CO₂ the number of molecules capable of emitting 4.3-μm radiation produced per cm of electron drift and per CO₂ molecule varied from 10^-17 cm^-2 at E/N = 6 x 10^-17 V cm² to 5.4 x 10^-16 cm^-2 at E/N = 4 x 10^-16 V cm². Here E is the electric field and N is total gas density. The excitation coefficients at lower E/N are much larger than estimated previously. A set of vibrational excitation cross sections is obtained for CO₂ which is consistent with the excitation coefficient data and with most of the published electron-beam data