<div dir="ltr">Hello,<div><br></div><div>I have a question about volumeID variable.</div><div><br></div><div>In my simulation I have a system of two plastic scintillating strips. At both ends of each strip, there are photomultipliers.</div>
<div><br></div><div>System looks like that:</div><div><br></div><div>PMT1==========PMT2 - strip with two PMTs </div><div><br></div><div> S - point source of back-to-back gamma in the middle of the system </div>
<div><br></div><div><div>PMT3==========PMT4</div></div><div><br></div><div>In my case, coincidence is a situation when I have optical photons at each of 4 photomultipliers at both strips.</div><div><br></div><div>When I analyze root output, I check if in single event there were hits with different volumeID[1]. Unfortunately for each event volumeID[1] has the same value for all hits so it gives me no coincidences.</div>
<div><br></div><div>But when I analyze positions of hits in each event and numbers of photons at each of four PMTs, I have many coincidences. Results of analysis looks like that:</div><div><br></div><div>Nr of photons at PMT1 || PMT2 || PMT3 || PMT4 || Nr of photons with volumeID[1]==0 || volumeID[1]==1</div>
<div>...</div><div><div>412 163 63 49 892 0</div><div>339 455 475 295 0 2314</div><div>184 82 599 696 2305 0</div><div>588 423 293 375 2487 0</div><div>553 478 51 56 0 1685</div><div>212 266 85 151 0 1045</div><div>269 345 79 81 1127 0</div>
<div>491 692 32 39 1876 0</div><div>387 602 31 8 1476 0</div><div>522 625 34 58 0 1825</div><div>587 722 46 57 2097 0</div><div>485 452 163 277 2060 0</div><div>89 144 619 640 2170 0</div><div>9 17 59 51 197 0</div><div>
52 96 376 91 788 0</div>
</div><div>...<br></div><div><br></div><div>All photons from all photomultipliers has only one value of volumeID[1] though they are from different volumes.</div><div><br></div><div>Is this a problem with my interpretation of volumeID variable or there is an error in GATE software?</div>
<div>It looks like GATE gives value of volumeID[1] of first hit in event for all hits in an event. </div><div><br></div><div>Thank you in advance for your help.</div><div><br></div><div>Best regards,</div><div>Paweł Kowalski,<br>
</div><div>National Centre for Nuclear Research,</div><div>Świerk Computing Centre</div></div>