Simplify the following text for a Grade 9 native English-speaking person.
Original: He , working with I.M. Kapchinsky , invented the principle of the radio frequency quadrupole ( RFQ ) , which revolutionized the acceleration of low energy ion beams .
Simplified: He , working with his friend I.M. Kapchinsky , created the Radio Frequency Quadrupole ( RFQ ) principle , which was very important dealing with the speed of low energy ion beams .