Low energy electron-cooling system and method

A method of cooling a low energy particle beam with an electron beam while containing neutralizing-background-ions, comprising the steps of:

• operating a vacuum-chamber to allow passage, merging and separation of said electron beam and said particle beam including an overlap-region wherein said electron beam and said particle beam are overlapped and where a first port allows entrance of said particle beam into said vacuum-chamber and where a second port allows exit of said particle beam out of said vacuum-chamber;
• operating an electron supply device including a cathode to produce said electron beam;
• operating an electron collector to collect said electron beam;
• operating a first electrode located downstream from said cathode and biased at a positive potential with respect to said cathode in order to accelerate said electron beam;
• operating a second electrode located downstream from said first electrode and upstream from said overlap-region and biased at a less positive potential than said first electrode to provide a first end of a longitudinal electric potential trap for said neutralizing-background-ions;
• operating a magnetic field production device to create magnetic fields to guide said electron beam along a desired path, merge and separate said electron beam and said particle beam, provide radial trapping for said neutralizing-background-ions and including an adiabatic-solenoid located upstream from said overlap-region to adiabatically increase the size of said electron beam, thereby reducing the transverse velocity spread within said electron beam;
• operating a third electrode located downstream from said overlap-region;
• and
• operating a fourth electrode located downstream from said third electrode and biased at a more positive potential than said third electrode to provide a second end of said longitudinal electric potential trap for said neutralizing-background-ions.