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Question Need help with overlap 

Forum: Geometry
Date: 31 Oct, 2016
From: Sambid Wasti <Sambid Wasti>

Hi everyone,

I am relatively new to Geant4. I did a geometry test and i got few overlap errors. The first overlap is shown as following:

.....
Checking overlaps for volume av_3_impr_1_LGBotAC_log_pv_3 ... OK! 
Checking overlaps for volume av_3_impr_1_AlTopBotAC_log_pv_6 ... OK! 
Checking overlaps for volume av_3_impr_1_ElecBotAC_log_pv_7 ... OK! 
Checking overlaps for volume ElecBotAC22_phy ... 
-------- WWWW ------- G4Exception-START -------- WWWW -------
*** G4Exception : GeomVol1002
      issued by : G4PVPlacement::CheckOverlaps()
Overlap with mother volume !
          Overlap is detected for volume ElecBotAC2_phy
          with its mother volume ElecBotAC_log
          at mother local point (25.159,-21.1087,-0.5), overlapping by at least: 2.48 cm 
NOTE: Reached maximum fixed number -1- of overlaps reports for this volume !
*** This is just a warning message. ***
.....

So, i went to my detector constructions and looked at the two volumes. ElecBotAC2_phy and ElecBotAC_log. The code is as following:

....
	// Electronics box
	//
	G4double ElecBotAC_X = 101.6*mm;
	G4double ElecBotAC_Y = 98.4*mm;
	G4double ElecBotAC_Z = 51.6*mm;
	G4VSolid* ElecBotAC_sol = new G4Box( "ElecBotAC_sol", 0.5 * ElecBotAC_X, 0.5 * ElecBotAC_Y, 0.5 * ElecBotAC_Z );

	// subtract inside volume
	G4double ElecBotAC1_X = ElecBotAC_X - 1.0*mm;
	G4double ElecBotAC1_Y = ElecBotAC_Y - 1.0*mm;
	G4double ElecBotAC1_Z = ElecBotAC_Z - 1.0*mm;
	G4Box* ElecBotAC1_box = new G4Box( "ElecBotAC1_box", 0.5 * ElecBotAC1_X, 0.5 * ElecBotAC1_Y, 0.5 * ElecBotAC1_Z );
	G4ThreeVector ElecBotAC1_pos = G4ThreeVector( 0., 0., 0. );
	ElecBotAC_sol = new G4SubtractionSolid( "ElecBotAC_sol", ElecBotAC_sol, ElecBotAC1_box, 0, ElecBotAC1_pos );

	// electronics box logical volume
	G4LogicalVolume* ElecBotAC_log = new G4LogicalVolume( ElecBotAC_sol, mAl6061, "ElecBotAC_log", 0, 0, 0 );

	// add PC board
	G4double ElecBotAC2_X = 2. * 25.4*mm;
	G4double ElecBotAC2_Y = 2. * 25.4*mm;
	G4double ElecBotAC2_Z = 1.0*mm;
	G4Box* ElecBotAC2_box = new G4Box( "ElecBotAC2_box", 0.5 * ElecBotAC2_X, 0.5 * ElecBotAC2_Y, 0.5 * ElecBotAC2_Z );
	G4LogicalVolume* ElecBotAC2_log = new G4LogicalVolume( ElecBotAC2_box, mPC, "ElecBotAC2_log", 0, 0, 0 );
	G4ThreeVector ElecBotAC2_pos = G4ThreeVector( 0., 0., 0. );
	new G4PVPlacement( 0, ElecBotAC2_pos, ElecBotAC2_log, "ElecBotAC2_phy", ElecBotAC_log, false, 0); 
....

I just have a box in a hollow box and the dimensions are not even close so i do not understand why i am getting an overlap issue here. Is there some basic stuffs that i am overlooking or i do not understand. Please help

-Sam-

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1 Note: Re: Need help with overlap   (Sambid Wasti - 31 Oct, 2016)
2 More: Re: Need help with overlap   (Gabriele Cosmo - 02 Dec, 2016)
1 Ok: Re: Need help with overlap   (Sambid Wasti - 06 Dec, 2016)
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