On Wednesday 01 March 2017 23:47:59 Kurt Jacobson wrote: > > What sort of bearings if any does the shaft spin in? > > Gene, I don't want to remove the encoder disk as it has to be > positioned just right, but I can just see through the encode slots > what looks to be the outer race and metal shield of a small ball > bearing that the shaft runs in. Pretty impressive build quality for > the cost even if it did come from china! > > What sort of an inspection tool with a radioactive sign on it were we > looking > > > at, along with its scintilator pulse outputs on the scope? > > I did not mean to include those pictures. It is an alpha particle > detector I am building. Don't know if you can see them but there are > some 1.75 thou tungsten wires stretched over the copper plate. The > wires are held at about +5kV and the copper is grounded resulting in a > high E field. When an alpha particle enters the field it is > accelerated and ionizes some air resulting in a spark. I use your > favorite device (Raspberry Pi) to count and log the sparks per sec, > and from that I can get the alpha flux. I just got a 500uCi Po210 > source (it's a static eliminator so exempt!!!) this morning and was > trying to determine the upper count rate of the Pi. Before I just had > a 1uCi Am241 source form a smoke detector. That Po210 source is hot! > but it has a half life of only 138 days vs 432 years for the Am so I > better play with it while it's still going strong. > > Hope that satisfies your curiosity. > > Kurt
Sure does Kurt, thanks. I didn't know alpha detectors could work at ambient atmo pressure, so I learned something too. Now if I can remember it in the morning... :( Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
