Hello there Claudio, It could well be that your plasma tube is overpressure: if the tube has not been run for a time the gas fill circuit may have given it a shot of gas at startup and overcompensated: as the tube warms up the tube goes overpressure and shuts off, at the moment, the bore pressure after warm-up is *just* below the cutoff value. with luck, running the laser will eventually bring the bore pressure back down, if it does not, and you experience repeated cutouts the solution is (if I remember correctly from our I90) to disable the overpressure cutout (which is what I suspect is closing down the tube) and run the laser for an extended period (anything up to a few weeks!) to bring the bore pressure down. There should be a test point on the laser control PCB which will give you a bore pressure readout (there will be a conversion factor from mV to millitorr) If the manufacturers are friendly they should be able to give you this info -certainly Coherent in the UK were very helpful in getting my overpressure Innova-90 running again) A good on line resource for lasers is http://www.cord.org/lev3.cfm/48 Arnold. >At 11:37 AM 8/20/01 +0200, Claudio Vallan wrote: > >>Hi, >> >>I am experiencing some problems with our Spinnaker Laser (from >>Spectra-Physics) and would like to ask if somebody can tell me what is >>happening. The Spinnaker is a water cooled 1 Watt Ion Laser. It's maximal >>output is 272 mW as measured on the multimeter of the remote controller. I >>usually use it at 30 mW, where it consumes 7.8 AMP. >> >>After coming back from Holidays (Laser has been 3 Weeks without running) >>the laser started to give troubles. It would turn up, but after a certain >>period at 30 mW it just would stop lasing (more than 30 minutes). The same >>effect could be reached in a few seconds if turning the power higher than >>150 mW. Though, it did not completely stop leasing, as there were sparks >>of blue light generated. The indicators on the remote control did not show >>anything unusual even when the laser was sparking (AC ON green / Emission >>white/ Sum Fault, Interlock and Water Flow OK). The only unusual thing >>which I had noticed was that some weeks ago, when putting the laser at >>maximum output it took it some seconds to reach 272 mW while usually that >>is not the case. After I let it run for a 30 Minutes at full output this >>behaviour had disappeared. I do not think the problem I have has to do >>with cooling as there seem to be no problem with the water (Though I can >>not be 100% sure). >> >>BD told me that I have to buy a new laser and while searching money to do >>that I replaced the Spinnaker with the second Laser (I am working on a >>Vantage), so we can at least work with 3 colours in the meanwhile. But when >>I tried to turn on the Spinnaker the next day (just for fun) the laser was >>working normal again. On the third day I had again the problems, but just >>once, when turning it on a second time it just worked normal. Since then it >>seems to have no problems. >> >>Can somebody tell me what happens? Will I need a new laser very soon? Could >>the laser be repaired? Does Spectra-Physics still exist and what is their >>address? Is there a good book out there about Lasers with the topics: how >>they work, how you maintain, troubleshoot and repair them? >> >>Answers to any of above questions very appreciated >> >>cheers >> >>Claudio >> >>=================================================== >>Claudio Vallan PhD Phone Lab: 031 / 632 88 76 >>FACS-LAB DKF Phone Office: 031 / 632 99 68 >>University of Bern E-Mail: vallan@dkf7.unibe.ch >>c/o Institute of Pathology >>Murtenstrasse 31 Insel hosptial area only: >>3010 Bern Beeper: 181 67 59 >>Switzerland >>=================================================== > >Derek Schulze >Flow Cytometry and Confocal Microscopy Facility Manager >Cancer Research Labs >Queen's University >Kingston, ON >Canada > > > _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ Arnold Richard Pizzey Department of Haematology Royal Free and University College London Medical School 98 Chenies Mews London WC1E 6HX U.K voice: +44 020-7679-6234 Fax: +44 020-7679-6222 email: a.pizzey@ucl.ac.uk _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
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