Patent ID: 6240932
Filing Date: 2001-06-05
Classification: H01J

Abstract:
A process for preliminary cleaning of each metallic part for assembly of a long-life hollow cathode assembly, comprising the steps of:a) using hand-coverings to eliminate hand contact with a hollow cathode assembly part;b) cleaning any residual dirt or grease from the part first by wiping it with a clean, lint-free and reagent grade acetone, followed by 95% ethyl alcohol;c) immersing the part to be cleaned completely in a beaker, said beaker being impervious to alcohol and to acetone, and said beaker containing a solution of acetone;d) placing the beaker in an ultrasonic cleaner having a heater under a fume hood;e) heating the ultrasonic cleaner for 30 minutes, with agitation thereof when the solution of acetone reaches 56 degrees C.;f) re-positioning the part as necessary in said beaker using clean tweezers to ensure that the part is completely immersed;g) removing the part from the beaker using tweezers, and draining any moisture from the part;h) immersing the part completely in a clean beaker, said beaker containing a solution of 95% ethyl alcohol;i) placing the beaker in an ultrasonic cleaner having a heater under a fume hood;j) heating the ultrasonic cleaner for 30 minutes, with agitation thereof when the solution of ethyl alcohol reaches 60 degrees C.;k) re-positioning the part as necessary in said beaker using clean tweezers to ensure that the part is completely immersed;l) removing the part from the beaker using tweezers, and draining any moisture from the part;m) drying the part with clean, oil-free nitrogen; and,n) storing the cleaned part in a nitrogen-purged, marked hermetically sealed plastic bag, for completely elimination of dust and debris that may contaminate a hollow cathode assembly part or subassembly.