1、Lessons Learned Entry: 0545Lesson Info:a71 Lesson Number: 0545a71 Lesson Date: 1996-04-01a71 Submitting Organization: LARCa71 Submitted by: Ruth M. AmundsenSubject: Ion Pump Recommendations: Baking, Ion Gauge Use Description of Driving Event: The MIDAS ion pump was at the top of its load rating when
2、 it was pumping the vacuum chamber. When the chamber was baked, the ion pump went out of range, so once the pump was turned off during this bake, on a prototype unit. This is not recommended for optimum pump operation. Also, when the ion gauge was operated, the pump would go out of range, which was
3、due to water being forced off the walls.Lesson(s) Learned: If a system is baked with the ion pump off, the contaminants driven off of the chamber walls during baking may be driven into the pump, and it will then take quite a while to be able to restart it. If the system is not baked sufficiently, th
4、en the act of turning on a vacuum ion gauge will drive so much water off the walls of the chamber and gauge that the ion pump may not be able to continue running.Recommendation(s): Ion pumps like to run as much as possible. If one is having problems or not stabilized, keep running it. Also, if you b
5、ake a system with an ion pump on it, keep the ion pump running during the bake. Bake the system to get water off the walls (especially if you will be running an ion gauge).Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: Provided by IHSNot for ResaleNo reproduction or ne
6、tworking permitted without license from IHS-,-,-N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 HardwareAdditional Info: Approval Info: a71 Approval Date: 1997-05-05a71 Approval Name: Elijah C. Kenta71 Approval Organization: 421a71 Approval Phone Number: 757-864-3345Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-