Other

USA As Represented by Secretary of the Navy

Leland Stanford Junior University

United States of America As Represented by the Secretary of the Air Force

Todd I Smith

John M Madey

Luis R Elias

David A Deacon

William M Fairbank

William B Colson

Michael S McAshan

Magnetic shielding of a magnet such as a first set of superconducting coils as used in nuclear magnetic resonance (NMR) applications includes a second set of coils around and spaced from the first set of coils. The magnetic flux of the second set of coils opposes and offsets the magnetic flux of the first set of coils in the region outside of the second set of coils but is less than the magnetic flux of the first set of coils in the region within the first set of coils. The uniformity of the magnetic flux within the first set of coils is not adversely affected by the magnetic flux produced by the second set of coils. In a preferred embodiment the coils of the first set are independently energized to establish a uniform field within the coils having suppressed lower order derivatives of flux with respect to position within the uniform field. The external field of the first set of coils comprises a dipole which is offset by the field of the second set of coils. Higher order multipoles beyond the dipole are also suppressed by the geometries of the two sets of coils.

Magnetic structure for NMR applications and the like

A storage-ring free-electron laser in which the electrons remain trapped in the optical potential wells formed by the laser fields. This is accomplished by preserving the electrons' bunched structure from pass to pass.

Isochronous free electron laser

The invention involves a free electron laser having reduced sensitivity to variations in the energy of the input electrons. This effect is achieved by first laterally dispersing the electrons in accordance with their energies and thereafter injecting the dispersed electrons with angular and/or lateral variations to alternate polarity deflecting means.

Free electron laser

A method and apparatus for constructing a continuous wave (CW) free elect laser (FEL) system capable of providing tunable high power laser radiation at short wavelengths using low-energy recirculating DC electron beams. This method replaces the static periodic magnetic field used in conventional FEL systems with an equivalently intense and continuous electromagnetic pump field having spatial periodicity less than 1 cm. The pump field is generated by a low-energy recirculated DC electron beam interacting with a transverse static periodic magnetic field.

Short wavelength free electron laser using low energy electrons

An apparatus and method is described for greatly enhancing the power output f a free electron laser. To enhance the electron kinetic energy that is converted to laser radiation, the wave amplification resonance condition is continuously changed along the length of the laser interaction region. The changing resonance condition is achieved by use of a static magnetic field transverse to the injected electron beam, the magnetic field having a longitudinal magnetic field gradient.

FEL Gain enhancement effect by a static transverse magnetic field with a

Improved gain and the elimination of beam insertion and extraction compensation in free electron lasers is realized by means of a helical periodic magnet. The magnet comprises one or more layers of coaxial bifilar helical conductors each being 180.degree. displaced and conducting current in opposite directions. The end portions of the magnet are tapered by extending successive layers one or more turns to provide a field gradient that uniformly decreases to zero.

Growing community of inventors

Palo Alto, CA, United States of America

Todd I Smith