<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Hi Dasuni,</div><div><br></div><div>if I remember correctly the 32 bit simulation is with geant4 8.1.p01 while </div><div>the 64 bit is 8.1.p02. If this is the case, it might be to due to improvement of the physics list. I do not expect to see any significant difference between 32 and 64 bits. Geant4 has been around in 64 bit since a long time so I would trust whatever the latest version of geant4 gives you.</div><div><br></div><div>best,</div><div>mauri</div><div><br></div><div><br></div><br><div><div>On Nov 4, 2010, at 6:12 PM, Dasuni Kalhari Adikaram Mudiyanselage wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><br><div class="gmail_quote">Hello,<br><br>I came up with some unexpected outcome with simulations in 64 bit machines. Simply, there is some additional neutron contribution in 64-bit mode than 32-bit.<br><br>Here with I’m sending you some figures that compare the new nominal configuration in 32-bit and 64-bit modes.<br>
<br>*Note that 10 million initial electrons were considered in each case.<br>*No floor particles are included. (i.e. electrons passes y<-610cm are cutoff.)<br><br>Figure 1: TOF and DC hits (Vertex plots Vy Vs. Vz)<br>
- Gives the counts of all the particles that hit the detectors. (No energy threshold is applied) <br>
- It is clear that there is a ~50% additional background in TOF and DC3.<br>- And ~25% additional background in DC1.<br><br>Figure 2: Energy dist. Of TOF hits<br>- The energy distribution of TOF hit (in log scale) tells us the, this additional particles carrying a neutron mass. (~940MeV)<br>
<br>Figure 3: Vertex plot for neutrons only.<br><br>And also we saw a smaller
increase in neutron flux when we simulating the test run conditions in 64 bit machines.<br><br>Looking forward for your comments and ideas to solve this Problem.<br><br>Sincerely,<br>Dasuni<font color="#888888"></font><br>
</div><br>-- <br>Dasuni Adikaram<br>
Graduate Research Assistant<br>Old Dominion University<br>Physics Department<br>4600 Elkhorn Ave<br>Norfolk, VA 23529<input type="hidden"><input type="hidden"><div></div><br>
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