US 7,321,604 B2
Ultra-short wavelength x-ray system
Donald Umstadter, Ann Arbor, Mich. (US); Fei He, Ann Arbor, Mich. (US); and Yue-Ying Lau, Potomac, Md. (US)
Assigned to The Regents of the University of Michigan, Ann Arbor, Mich. (US)
Filed on Jan. 07, 2004, as Appl. No. 10/752,604.
Prior Publication US 2005/0147147 A1, Jul. 07, 2005
Int. Cl. H01S 3/00 (2006.01); H01S 3/09 (2006.01)
U.S. Cl. 372—2  [372/73] 29 Claims
OG exemplary drawing
 
1. A method for generating electromagnetic radiation comprising:
producing free electrons;
selecting from said free electrons a group of electrons having an energy spread less than the remaining of said free electrons; and
undulating the group of free electrons with an undulator in an undulation zone, said undulator having an intensity sufficient to cause the emission of radiation from the group of electrons and causing the electron radiation to interact with radiation from the undulator to bunch the group of electrons, whereby such bunching generates further emission of radiation, wherein said selecting is accomplished by magnetic filtering and said magnetic filtering is accompanied by refocusing of the electron beam to the undulation zone.