A system for reducing clogging and deposition of feed gas on a gas tube entering an ion source chamber is disclosed. To lower the overall temperature of the gas tube, a gas bushing, made of a thermally isolating material, is disposed between the ion source chamber and the gas tube. The gas bushing is made of a thermally isolating material, such as titanium, quartz, boron nitride, zirconia or ceramic. The gas bushing has an inner channel in fluid communication with the ion source chamber and the gas tube to allow the flow of feed gas to the ion source chamber. The gas bushing may have a shape that is symmetrical, allowing it to be flipped to extend its useful life. In some embodiments, the gas tube may be in communication with a heat sink to maintain its temperature.