Publisher Summary The heat pipe has been studied for a broad variety of applications, encapsulating almost the complete spectrum of temperatures encountered in heat transfer processes. These applications range from the use of liquid helium heat pipes to aid target cooling in particle accelerators, to cooling systems for state-of-the-art nuclear reactors and potential developments aimed at new measuring techniques for the temperature range 2000-3000°C. Heat pipes have been used extensively in a variety of energy storage systems. The benefits of the heat pipe based on isothermalization/temperature flattening are also remarkable. Heat pipe technology offers a number of potential benefits to reactor performance and operation. There has been an increased interest in achieving uniformity of reactor temperature, and thus good product quality. The reason for this is that increased yield of high purity, high added value chemicals. Heat pipes, certainly at vapor temperatures up to 200 °C, have probably gained more from the developments associated with spacecraft applications than from any other area. Heat pipes are widely used in energy conservation. Another sector that has benefited from the unique properties of the heat pipe is the rapidly growing food industry.