NOVELTY - The system comprises an elongated pipe (12) defining a reaction chamber for fluid flow of a liquid in an axial flow direction, an electrode disposed within the reaction chamber and extending coaxially in the direction of fluid flow, a pulsed voltage source electrically connected to the pipe and the electrode, and an ionizing radiation source (18) directing ionizing radiation (20) in the reaction chamber transverse to the direction (16) of fluid flow. The pipe is made from an electrically conductive material. The electrode is electrically insulated from the pipe.    USE - The system is useful for conversion of molecular weights of fluids such as hydrocarbons including crude oil, kerosene, diesel oil, ethanol and vegetable oil by cracking or reformation.    ADVANTAGE - The system increases the monetary value and essential resources of petroleum through the removal of impurities and by effective and economical conversion of molecular weights of hydrocarbons.    DETAILED DESCRIPTION - The system comprises an elongated pipe (12) defining a reaction chamber for fluid flow of a liquid in an axial flow direction, an electrode disposed within the reaction chamber and extending coaxially in the direction of fluid flow, a pulsed voltage source electrically connected to the pipe and the electrode, and an ionizing radiation source (18) directing ionizing radiation (20) in the reaction chamber transverse to the direction (16) of fluid flow. The pipe is made from an electrically conductive material. The electrode is electrically insulated from the pipe. The voltage source impresses opposite polarities on the pipe and the electrode to generate a radially extending electric field between the pipe and the electrode. The liquid flowing through the pipe is ionized and energized so that the molecular composition of the liquid is reformed, converted to compounds of different molecular weight. A magnet is disposed adjacent to the pipe and oriented to generate a magnetic field axially though the reaction chamber defined by the pipe. The ionizing radiation source is disposed external to the pipe and disposed internal to the electrode, and comprises a source of gamma ray radiation. A heat exchanger (20) is connected to the pipe for removing and recovering heat energy generated during conversion of the molecular weights of the fluid, and comprises a conduit exiting and re-entering the pipe and a unit for extracting heat from a portion of the conduit external to the pipe. A transparent window (14) is formed in the pipe for viewing and analyzing the fluid. An INDEPENDENT CLAIM is included for a method for conversion of molecular weights of a liquid.    DESCRIPTION OF DRAWING(S) - The figure shows a side view of a system for conversion of molecular weights of fluids.    Elongated metal pipe (12)    Window (14)    Flow direction (16)    Ionizing radiation source (18)    Ionizing radiation (20)    Heat exchanger. (22)