X-ray is an important tool for charactering and analyzing materials.However,current X-ray generation is cost with low efficiency.For X-ray tube,which is mostly used in laboratories,only has an energy usage of 1%with a...X-ray is an important tool for charactering and analyzing materials.However,current X-ray generation is cost with low efficiency.For X-ray tube,which is mostly used in laboratories,only has an energy usage of 1%with all other energy dissipated into tremendous heats,and it needs continuous cool water flows to cool down the cathode.It generates X-ray by the bremsstrahlungofhighenergy electronsbombardingonthecathodetarget,thebremsstrahlungwouldcontainX-raywith sufficiently high energy of the electrons.But most part of the electron energy becomes heats.In order to generate X-ray more cheaply with higher efficiency,methods about reusing the released heats during the working of the X-ray tube are brought up.Mimicking the photovoltaic effect,nonequilibrium carriers could also be injected via thermion emission when heating a metal,such injection is same to that of photonic injection which produces electromotive in a photovoltaic cell.In a photovoltaic cell the electron-hole pair generated by incident photons are nonequilibrium carriers that causes electromotive,while the thermion emission creates such electron-hole pairs via thermal excitation.Connecting metals suitable for thermion emission from the cathode into the p-n junction so that thermions as nonequilibrium carriers can be well injected into the p-n junction when the metals are heated by the cathode,with Thomson effect which enhances such injection,a thermal voltaic cell can be constructed and it can produce electricity only by heating the metals outside.Applying such thermal voltaic cell into current X-ray tube,it would produce electricity while absorbing the tremendous heats emerges when X-ray tube is working.Water flows are still used to control the temperature,but letting them boiling to keep the cathode at a temperature best for thermal voltaic cell,and the vapor may be used to drive a mini thermal power plant.In this way,the energy usage could be modified to a higher proportion.Stepwise up-conversion is possible to generate X-ray more cheaply but there are 展开更多
文摘X-ray is an important tool for charactering and analyzing materials.However,current X-ray generation is cost with low efficiency.For X-ray tube,which is mostly used in laboratories,only has an energy usage of 1%with all other energy dissipated into tremendous heats,and it needs continuous cool water flows to cool down the cathode.It generates X-ray by the bremsstrahlungofhighenergy electronsbombardingonthecathodetarget,thebremsstrahlungwouldcontainX-raywith sufficiently high energy of the electrons.But most part of the electron energy becomes heats.In order to generate X-ray more cheaply with higher efficiency,methods about reusing the released heats during the working of the X-ray tube are brought up.Mimicking the photovoltaic effect,nonequilibrium carriers could also be injected via thermion emission when heating a metal,such injection is same to that of photonic injection which produces electromotive in a photovoltaic cell.In a photovoltaic cell the electron-hole pair generated by incident photons are nonequilibrium carriers that causes electromotive,while the thermion emission creates such electron-hole pairs via thermal excitation.Connecting metals suitable for thermion emission from the cathode into the p-n junction so that thermions as nonequilibrium carriers can be well injected into the p-n junction when the metals are heated by the cathode,with Thomson effect which enhances such injection,a thermal voltaic cell can be constructed and it can produce electricity only by heating the metals outside.Applying such thermal voltaic cell into current X-ray tube,it would produce electricity while absorbing the tremendous heats emerges when X-ray tube is working.Water flows are still used to control the temperature,but letting them boiling to keep the cathode at a temperature best for thermal voltaic cell,and the vapor may be used to drive a mini thermal power plant.In this way,the energy usage could be modified to a higher proportion.Stepwise up-conversion is possible to generate X-ray more cheaply but there are
