Ginga's primary science instrument was the Large Area Proportional Counter (LAC). At the time, the LAC was the largest X-ray detector flown on a satellite. The LAC consisted of 8 identical proportional counter units.
When an X-ray entered the LAC, it would enter a chamber filled with a mixture of argon, xenon and carbon dioxide gases. The X-ray would interact with the gas, causing a cascade of electrons that would be detected by the LAC electronics. The LAC was sensitive to X-rays in the range of 1.5 to 37 keV.
