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Re: hdds and hdfast
Curtis,
I have fixed the problems you raised and checked new sources for the
hdds tools into the Gluex cvs repository at cvs.jlab.org. People should
update their hdds area and do "make hddsMCfast.db" to try the new
database so that we are all working from the same sources. Sorry for
the delay in completing the fixes, but some changes were needed to make
the code easier to follow. Hopefully bugs will be fixed more quickly
from now on.
Richard Jones
Curtis A. Meyer wrote:
>Hi Richard -
>
> we have run into issues with the material definitions in hdds when a file
>is produced for hdfast. It appears that when compound materials are created
>in hdds, there are missing arguments in the hdfast geom file.
>
>A material requires a name, plus 7 more parameters (A, Z, density, rad.
>length, Nuclear Interaction Length, Nuclear Collision Length and de/dx).
>The hdds output file only contains the last 5 for non-elements, missing two very
>important numbers.
>
>A mixture requires the name, the number of materials in the mixture (up
>to 5), then a list with the names of the materials involved followed by
>the relative proportions of each. The hdds file listed the number and the
>names of the materials involved, but never the proportion to mix them at.
>
>Finally, there is a maximum number of materials + mixtures in mcfast of about
>50. We need to only define the stuff that we really need and is not already
>defined in the mcfast material and definition files. We can do this by hand
>now after we have produced the file, but it would be better to perhaps add
>some sort of tag the specifies what needs to be produced for hdfast, rather than
>producing everyhting that is needed in geant.
>
>Lastly, there needs to be a couple of lines about hitsontarcks in order for
>stuff to work properly.
>
>include db/hitsontrack.db
>make HitsOnTrack 4 0 0
>
>
>
>
>The following came from Zisis anf one of his students:
>------------------------------------------------------------
>
>This is a list of the problems with the latest hddsMCFast.db that Curtis
>Meyer recently sent us. Attached, you will find hdds.db (hddsMCFast.db
>from Curtis, just renamed. Doesn't work), superdb.db (The hand-made
>database complete with comments. Works) and mixtures.db & materials.db
>(I've defined all of the materials and mixtures from hddsMCFast.db right
>in the their databases instead of in the geometry db). Please forward to
>Curtis.
>
>Thanks.
>
>
>========
>
>After receiving the latest version of hddsMCFast.db (I've attached it,
>named hdds.db), I tried to run a simulation using it but was getting
>errors.
>
>Tired of playing with this database, we decided to use the version of
>the database that we knew worked, HDFast.db.cvs, and manually change
>each parameter to match the file that you sent us. This version
>(superdb.db) worked,
>but we only saw 50% acceptance. The problem, it turns out, is that the
>database that you sent does not contain the following at the end:
>
>include db/hitsontrack.db
>make HitsOnTrack 4 0 0
>
>Once I added these lines to the end, I saw ~95% acceptance.
>
>Another problem that I saw with hddsMCFast.db was the definition of the
>materials/mixtures:
>
>A material requires a name, plus 7 more parameters (A, Z, density, rad.
>length, Nuclear Interaction Length, Nuclear Collision Length and de/dx).
>Your file only contained the last 5 for non-elements, missing two very
>important numbers.
>
>A mixture requires the name, the number of materials in the mixture (up
>to 5), then a list with the names of the materials involved followed by
>the relative proportions of each. Your file listed the number and the
>names of the materials involved, but never the proportion to mix them at.
>
>The XML files contain all of this information, so clearly it is not
>being handled correctly by the hdds-mcfast program. What I have done is
>taken the materials that are actually used in our geometry and copied
>them directly into materials.db. I calculated A and Z where necessary. I
>have also added the mixtures to mixtures.db, using the proportions
>defined in the XML files.
>
>Also, there is an issue with units between the old and new materials
>information. As you can see in materials.db, most materials do not have
>the same values for the final 4 parameters, some differening by a few
>orders of magnitude. Which set of units do we want to be using?
>
>Finally, some suggestions for handling the output from the hdds-mcfast
>program. We feel that it is important for the output database to contain
>comments, similar to superdb.db (attached). The current format is very
>hard to
>follow, and the numbers seem meaningless if I want to work on it. Also,
>perhaps a better way to handle the materials and mixtures would be to
>have hdds-mcfast output the definitions directly into materials.db and
>mixtures.db, rather than defining them at the top of hddsMCFast.db. It
>seems pointless to have separate db's if we are going to redundantly
>define all of the materials in the geometry database.
>
>Hopefully I've given you some useful information, not just repeating
>things that you are already aware of.
>
>Cheers,
>Blair Jasper
></pre>
><pre cols="72" class="moz-signature">--
>Dr. Zisis Papandreou | email: <a class="moz-txt-link-abbreviated"
> href="mailto:zisis@uregina.ca">zisis@uregina.ca</a> Department of Physics |
> tel. : (306) 585-5379
>University of Regina | tel. : (306) 585-4149
>Regina, SK S4S 0A2 | fax. : (306) 585-5659
>
>World Wide Web: <a class="moz-txt-link-freetext"
> href="http://www.phys.uregina.ca/sparro/zisis/">http://www.phys.uregina.ca/s
>parro/zisis/</a> </pre>
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