Ultrafast Gas Curtain and Wire-Reinforced X-Ray Window Debris Shields

Period of Performance: 05/14/1998 - 11/14/1998

$100K

Phase 1 SBIR

Recipient Firm

Alameda Applied Sciences Corp.
3077 Teagarden Street Array
San Leandro, CA 94577
Principal Investigator

Abstract

Alameda Applied Sciences Corporation (AASC) proposes to develop two components of a three-component, survivable debris shield for large area test exposures to cold (1-5keV) x-rays. These elements also have commercial potential in accelerators and in radiography. The elements are: an ultrafast gas curtain designed to be located close to the x-ray source to deflect plasma debris as well as ~um sized debris particles so that they miss the test object located at >15 cm from the source; a 1-D or 2-D grid that supports a thin soft x-ray window, making it far more robust than a free-standing foil, with high open area (~90%) and negligible artifacts in the test plane due to the grid structure. The role of this robust transmissive membrane is to stop those particles that have not been deflected by the gas curtain. These two elements are combined with an electromagnetic shutter, whose role is to stop larger but slower moving particles and late time hot gases. The three-pronged defense proposed by AASC, the gas curtain, electromagnetic shutter and robust transmissive x-ray window, constitute a debris mitigation system that is useful for today's simulators, while being eminently scaleable to the larger fluence-area products required by tomorrow's simulators. When z-pinch or laser produced plasmas are used as point x-ray or XUV sources for sub-micron lithography and microscopy, the mask/wafer region must be shielded from particulate debris. The debris shields developed here might be suitable for this purpose. Accelerator beamlines might also use these shields to protect delicate components from debris due to failures in vacuum beamlines or to make vacuum windows more robust.