RE: geometry setup problem

From: Chris Theis (
Date: Thu Feb 07 2008 - 09:40:54 CET

  • Next message: Paola Sala: "Re: geometry setup problem"

    Dear Jiasen,

    I quickly checked det1b.inp and your geometry is (mathematically)
    correct. Your problem is not related to the number of subtractions
    within a single boolean operation, which to my experience is huge and
    I've never reached it even with very complex geometries. But it's
    related to the use of parentheses. There was a similar problem just 3
    weeks ago, so I'll refer you to the list archive for more details:

    In the log file you will find an error message at the top above (!!!)
    the license text which tells you that there has been a subscript out of
    range in the rpnorm function. This indicates that the code crashed
    during the expansion of parentheses. However, to my knowledge there is
    no way for the user to find out at which point this happened exactly. If
    anybody knows an easy way I'd be very interested. From my experience I'd
    suspect the culprit region is RCC03.

    In order to run your geometry in FLUKA you will have to simplify the
    geometry. In order to make your life much easier you could consider
    using bigger axis aligned boxes (RPP) in combination with a number of
    cutting planes to obtain the small slabs. This makes the construction
    easier as there is no need to define all of them with infinite planes as
    it was very common in MCNP(X). Furthermore with this approach you can
    avoid the use of parentheses in your case for RCC03.

    Hope that helps

    Chris Theis
    CERN/SC-RP - European Organization for Nuclear Research
    1211 Geneva 23, Switzerland
    Phone: +41 22 767 8069 Office: 892-2A-015
    e-mail: www:

    > -----Original Message-----
    > From: [mailto:owner-fluka-
    >] On Behalf Of Jiasen Ma
    > Sent: 06 February 2008 20:46
    > To:
    > Subject: geometry setup problem
    > Dear All,
    > I have a detector which is a quare around the square beam hole.
    > Inside it, there arelots of tungsten(36) and scintillator(42) plates
    > hold in a iron shell.
    > I used a series of infinite half space or planes to define them as in
    > the attached det1a.inp and det1b.inp. Then I substract all the
    > volumes(W and scint plates) in the world definition. But Fluka won't
    > run on the card. The program will be aborted. If I only use five
    > volumes or less, then it works.
    > The difference between det1a.inp and det1b.inp is just that det1a.inp
    > has less bodies defined.
    > The same problem happened when I was defining the other detector as in
    > det2.inp where there are just BOXs, ARBs, and no infinite planes. The
    > only difference is that the number limit for different bodies went up
    > to 10.
    > It seems to me that it's not possible to substract more than a certain
    > number of boolean operation of different bodies although it works with
    > any numbers of single bodies.
    > Is this true? Can I get around this to define this kind of geometry?
    > Thanks a lot. Sorry if the input cards are too messy.
    > Jiasen

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