<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>Hi everyone,<br><br>We are performing CT simulation on a big water phantom. We would like to see all the Compton scattering within the phantom. If I am right, we should use attachPhantomSD. I would assume that if we use attachPhantomSD, all the interactions will be recorded in a root file. However, when we looked at the root file, we almost didn’t see Compton events.<br><br>I captured the histograms of "nPhantomCompton" and "ComptVolName" in this email. Does anyone have any insight with this problem?<br><br>Thanks,<br>Ney</div></div><img height="315" width="240" apple-width="yes" apple-height="yes" id="5d1628eb-fd5a-4107-89e9-8932b820c36b" src="cid:175E18C6-988F-47D2-8897-2E54AC018CE7@mgh.harvard.edu"></body></html>