Production and qualification of an electrospun ceramic nanofiber material as a candidate future high power target

Abstract

In an effort to develop and design next generation high power target materials for particle physics research, the possibility of fabricating nonwoven metallic or ceramic nanofibers by electrospinning process is explored. A low-cost electrospinning unit is set up for in-house production of various ceramic nanofibers. Yttria-stabilized zirconia nanofibers are successfully fabricated by electrospinning a mixture of zirconium carbonate with high-molecular weight polyvinylpyrrolidone polymer solution. Some of the inherent weaknesses of electrospinning process like thickness of nanofiber mat and slow production rate are overcome by modifying certain parts of electrospinning system and their arrangements to get thicker nanofiber mats of millimeter order at a faster rate. Continuous long nanofibers of about hundred nanometers in diameter are produced and subsequently heat treated to get rid of polymer and allow crystallize zirconia. Specimens were prepared to meet certain minimum physical properties such as thickness, structural integrity, thermal stability, and flexibility. An easy innovative technique based on atomic force microscopy was employed for evaluating mechanical properties of single nanofiber, which were found to be comparable to bulk zirconia. Nanofibers were tested for their high-temperature resistance using an electron beam. It showed resistance to radiation damage when irradiated with 1 MeV Kr^{2++} ion. Some zirconia nanofibers were also tested under high-intensity pulsed proton beam and maintained their structural integrity. This study shows for the first time that a ceramic nanofiber has been tested under different beams and irradiation condition to qualify their physical properties for practical use as accelerator targets. Advantages and challenges of such nanofibers as potential future targets over bulk material targets are discussed.