MINOS detector simulation: gminos

What's new with `gminos`

News about gminos, neugen and reco_minos are now topics under the Minos HyperNews web server. More general topics on code management and misc software issues, This threaded system retains a history of questions, comments and remarks. A Web page of status & milestones information that documents major updates and improvements prior to HyperNews (6/02/97).

Numbering Conventions and Co-ordinate Systems

A document (NuMI-L-243 local ps copy) has been written to describe the various conventions used in gminos. Diagrams of the 4 defined detector orientations (X,Y,U,V) are included. Also included are descriptions of standard subroutine calls used to transform co-ordinate systems or retrieve position information.

Using the software at FNAL

The standard code repository at FNAL (the labyrinth) at Fermilab has been set up on the afs filesystem. Executables, and libraries have been created for a variety of different platforms. Scripts are available to help the average user perform common tasks.

Standard files and example reader(s)

Standard files (from the FNAL farm) (the page pointed at by this link is outdated; see the link under http://www-numi.fnal.gov:8875/fnal_minos/computing/computing.html for a more recent index).
Outdated files
- the ffr files used to make them
reading files with TIP
reading file with FORTRAN (reco_minos)

Subroutine call tree

Call trees of who-calls-whom in gminos have been generated in text (html) and graphical (postscript) form. The html version has annotations with brief descriptions of the purpose of many of the routines. The graphical version includes file information (including the subdirectory name). No guarantees on how up-to-date or accurate either is at any given time... Note added 1997.07.24: These were generated ~May 1996, and are almost certainly out-of-date

Data Structures & IO

ADAMO data structures:

For those who haven't yet read any of the ADAMO reference material, RWH has written up (his interpretation of) some of the terms used in ADAMO. A tutorial on ADAMO is available and should be read by everyone planning on accessing the data. Discussions about using ADAMO on MINOS can also be found in the HyperNews sub-thread "ADAMO -- getting started, Q&A".

Most of these data structures are the output from the Monte Carlo (or in some cases an intermediate structure, possibly kept for convenience sake and historical record). The reconstructed quantities describe data structures that are the end result or intermediates to the event analysis.

Current MINOS .ddl files

Still missing are some RSet specifications.

Making choices

User specification of the geometry:

Hand editing a full ADAMO specification of the geometry is infeasible: many of the values are calculated from the interplay of the components. Secondly, such an approach is unwieldy in the case of relatively standard setups. Instead we plan to implement a simpler method using reduced ADAMO tables specific for user input. This development work is still in its infancy.

In the mean time, FFREAD cards to override default values in specifying a geometry are in place for many of the changes that a user might desire. This approach has not fully implemented all possible knobs and switchs but it does provide much of them.

A description of the geometry cards is available.

Other user specifications:

Other FFREAD cards (non-geometry) that allow the user access to knobs, buttons and switches concerning other aspects in running gminos A description of the cards is available.

User specification of the neutrino interaction type:

Nothing has yet been decided on how users specify what interactions to model or how input neutrino beams get selected. This will probably depend on what "knobs" and "buttons" the beam file and event generator packages provide. These should allow, at minimum, the user to select:

the beam (WBB, NBB, #horns...)
possibly additional shifts of hall vs. beam axis
allowed reactions (CC, NC, QE, QE+pi)
allowed oscillations (eg. nu_mu -> nu_e)
delta_m**2, sin(2theta)**2
choice of structure functions for DIS

Tau Talk

There is a growing interest in supplementing (not supplanting) the course grained MINOS far detector with a wall of emulsion based detectors. These would consist of alternating layers of thin iron (~1mm) and sheets of plastic backing (~1mm) that have emulsion on both faces (~70micron thick). The necessity of additional tracking hardware is a topic that warrents further study. Additions to the gminos geometry have been implemented and futher discussions concerning the simulation of this proposal have been moved to a separate page

Other Items

Random number generators

Alan Wehmann (Fermilab X4692, M.S. 220) wrote up some documentation on the random number generators GRNDM and RANECU.

Until such time that Fermilab gets their server up and running, IU will be happy to provide a home for documentation that our Fermilab collaborators (or others) would like to distribute via the Web.

Tigger planes

At the 3/7/96 video conference the concept of trigger planes or sparsely placed special planes (eg. every 10th) was brought up. This was the first I (RWH) had heard the idea suggested. Is this a serious proposal, something we need to implement in the geometry at some point? The current geometry is limited (in each supermodule) to a regular structure based on a order parameter of 16 pairs (passive absorber, active detector) of planes. One can independently choose the type & configuration of each plane, but they must come as pairs (though dummy plane types allow the user to circumvent this restriction). The orientation of each active plane can also be specified (currently only X,Y,U,V for rotations of 0, 90, 45 and 135 degrees). The pattern then repeats... It should be possible to implement almost any configuration of trigger planes that can be reasonably imagined in this scheme.

Older Items

These are generally resolved issues.

Overview

A (possible) breakdown into the component steps of the simulation.
General thoughts about data structures and IO.

Neutrino Event Generator

A separate committee has been formed to study the issues of modelling the "physics". One topic concerns how to combine the physics processes of quasi-elastic, resonance production and deep-inelastic scattering in the problematic `medium' energy range. Other issues include: nuclear effects (Fermi motion, shadowing, anti-shadowing, the EMC-effect), higher twist, hadronization models, and charm production.

This "committee" is really a "working-group" made of individuals with an active interest in these topics; all are welcome to join. Current membership:

Jorge Morfin
Hugh Gallagher
Alan Wehmann
Maury Goodman
Rob Edgecock
Robert Hatcher - "secretary"

If you'd like to be added/removed please mail me at: hatcher@astro.indiana.edu

Jorge wrote up an proposal for studying additional interesting neutrino physics topics (besides oscillations); this group will be instrumental in implementing the code necessary to simulate the physics described in that message.

putting the pieces together

Discussions of integrating the interaction event generator (that knows about "physics") into gminos (which knows about the detector "geometry") and how these interface with routines to read the neutrino flux files (which reflect the "beam" information) have been moved to a separate page:
http://mimosa.astro.indiana.edu/minos/simulation/neu_gen_discuss.html
(This integration was essentially complete as of July 1996)

Back in Jun 1996, I (RWH) sent out a general message concerning working groups focussed on (a) improving the neutrino physics and (b) flux, neugen, gminos integration.
(The current relevance of particular items may vary)

Other views

A link to Robert Hatcher's page on similar topics. Views and opinions on that page are his own and do not necessarily reflect those of, well, anyone else.

hatcher@astro.indiana.edu

Last modified: Thu Jul 24 14:43:17 1997

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