Mass Spectrometry: Alpha Cleavage of Ketones

After a ketone is put through electron impact (EI), the bond NEXT to the carbonyl carbon breaks apart. This gives a radical (uncharged) and a positive ion. Which side of the ketone breaks off? Usually, the LONGER chain of the two will be the one to fall off Which fragment gets the positive charge? Usually the fragment that has the C=O keeps the + charge because it's resonance stabilized. Check me out: http://www.chemistnate.com