<html> <head> <meta http-equiv="content-type" content="text/html; charset=GB2312"> </head> <body bgcolor="#FFFFFF" text="#000000"> Dear Gate users: I am using the Gatev6.1 to simulate the PET<a class="search-js" href="http://dict.youdao.com/w/simulate/" ,="" onmousedown="return rwt(this, '/search?q=simulate&keyfrom=E2Ctranslation')" style="color: rgb(53, 161, 212); outline: 0px; text-decoration: none; font-family: Arial, sans-serif; font-size: 14px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: 24px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;"></a>, I want to generate a box-style source and am not sure How to set the keywords (paralp,parthe,parphi). The following is my code: /gate/source/addSource twogamma1 /gate/source/twogamma1/setActivity 100000 becquerel /gate/source/twogamma1/setType backtoback /gate/source/twogamma1/gps/particle gamma /gate/source/twogamma1/gps/energytype Mono /gate/source/twogamma1/gps/monoenergy 511 keV /gate/source/twogamma1/gps/type Volume /gate/source/twogamma1/gps/shape Para /gate/source/twogamma1/gps/halfx 0.5 mm /gate/source/twogamma1/gps/halfy 0.509615 mm /gate/source/twogamma1/gps/halfz 0.509615 mm /gate/source/twogamma1/gps/paralp 90 deg /gate/source/twogamma1/gps/parthe 90 deg /gate/source/twogamma1/gps/parphi 90 deg /gate/source/twogamma1/gps/angtype iso /gate/source/twogamma1/gps/mintheta 0. deg /gate/source/twogamma1/gps/maxtheta 180. deg /gate/source/twogamma1/gps/minphi 0. deg /gate/source/twogamma1/gps/maxphi 360. deg /gate/source/twogamma1/attachTo voxel1 Thanks a lot! </body> </html>