Thermal bremsstrahlung

How are the X-rays produced in this hot gas? Since the gas temperature is very high, most elements are highly ionised, and so the gas is really a hot plasma. The negatively charged electrons in this plasma experience a force when they pass close to an ion, and an accelerating charge emits electro-magnetic dipole radiation: this is the radiation that we observe. Since the electron looses energy in the encounter, it will slow down. Hence the name thermal bremsstrahlung^7.3. And as the electron slows down, the plasma also looses energy, and so the gas cools.^7.4 The electron is not bound to any particular ion throughout the interaction and this process is therefore also called free-free radiation. This is all you need to know about this, but if you want more details, here they come.