Problem 458

Summary:	Problems with G4Torus
Product:	Geant4	Reporter:	tumakov
Component:	geometry/solids	Assignee:	Vladimir.Grichine
Status:	CLOSED LATER
Severity:	major
Priority:	P2
Version:	other
Hardware:	Other
OS:	Linux
URL:	http://meco.ps.uci.edu/~tumakov/Geant4_problems_fixed.html

Description tumakov 2003-02-20 18:01:36 CET

The problem with geometry check comes when Torus volume was placed.
(Rmin=25cm,Rmax=26.cm,Rtorus=290cm. Phy_start=0 deg; Phy_range=90deg.
Xc=104cm,Yc=0cm;Zc=290cm
Torus  was rotated by -90deg around X axis.

Somehow I fixed the problem which I think is related to the machine accuracy.

But I want the authorized people check my changes, or properly fixed
the ploblem themselves, so that this problem will not appear in future versions
of GEANT4.

The modified files are in
http://meco.ps.uci.edu/~tumakov/Geant4_problems_fixed.html

		Regards, Vladimir Tumakov

Comment 1 tumakov 2003-02-20 18:04:59 CET

Release  is Geant4.5.0

Comment 2 tumakov 2004-03-11 12:19:59 CET

Year ago I reported this problem. Now we are starting more intense
simulations with Geant4 for MECO experiments.
Toroidal magnets are essentual parts of snake solenoid in MECO experiment.
Original  G4Torus.c makes segmentation fault even in simple
procedure of /geometry/test/run
and during the particle tracing as well.

My edition by cutting off some bad parts of G4Torus.c file
helps to escape this problem, but I don't think it is a correct way to proceed.

It looks  strange to me  that in simple geometry (only one volume -
quater of torus) Geant4 has problem.

Of course, if you agree with my way to solve the problem,
than just include my version of G4Torus.cc,G4PolynomialSolver.icc files
into core Geant4 code.
   Regards, Vladimir Tumakov

Comment 3 Vladimir.Grichine 2006-03-24 01:40:59 CET

We verified the geometry specified here about
G4Torus, using latest version of Geant4 (8.0.p01)
which includes revised code for G4Torus. We
could not reproduce the problem reported any
longer.