User specification of MINOS geometry

Note: This is still fairly preliminary. This is documents most of the geometry/materials FFREAD cards that were defined as of 5/1/96 (partially updated 2006-03-14). The details are still subject to change. The use of FFREAD as the basic mechanism was chosen simply for convenience (it is a CERN product, it is straightforward, it works straight out of the box, it's already used by GEANT).

FFREAD long writeup @ CERN

Note: a common mistake is to overwrite previously set values by re-issuing the same card without using a positioning indicator ('='). In particular:

leaves the array held by RTAG with the values:
'F4PL' 'F5PL' 'F3PL' .... remainder unchanged ...
There are two possible means of achieving what the user probably desired. First, one can use continuation cards; these are lines without a key name as the first element. Such lines are associated with the key that immediately preceded them. The alternative is to explicitly position the additions (eg. change the second card to RTAG 4='F3PL' 'F5PL'). It is only necessary to position the first element on a card as futher elements on the same card are incremented from that position.

Choosing from defaults

Note:Default configurations will get implemented. But the details of exactly what they are has not yet been decided. When they are "set in stone" then they will get documented. Interested parties should contact the author(s) about what defaults they wish to see implemented.

SUPR card

Usage: SUPR isuper
   SUPR 2
The SUPR card chooses the super-module organization out of a predefined list, eg. The default would be to build the basic LST far detector. Other pre-defined setups (including sub-variants) could be added to the list upon demand.

Deviations from basics choices

For further discussion of what some of the terms in this section mean, please refer to the documentation in the beginning of the Geometry ADAMO specification.

Cards to specify the super-module organization

C overall detector layout
VHAL 700. 700. 4500.
NPLS   300    300    300      0
SSPA 2*100. 2*200. 2*150. 
SX0      0.     0.     0. 
SY0      0.     0.     0. 
CSET     1      1      1  
CCUR   -1.    -1.    -1.  
S1PA 'C1L1' 'C1L1' 'C1L1' 'C1L1' '....'
S2PA 'B4F4' 'B4F4' 'B4F4' 'B4F4' 'B4T1' '....'
S3PA 'C1R1' 'C1R1' 'B1L1' 'B1L1' 'B4F4' 'B4F4' '....'

VHAL card

Usage: VHAL xhalf yhalf zhalf
The VHAL card sets the size of the 'HALL' volume. Sizes are given as half-lengths in cm.

LTHK card

Usage: LTHK thickness
The LTHK card sets the thickness of the liner volume 'LINR' surrounding the 'HALL' volume. The thickness given in cm, which is added to the size of the 'HALL'. This volume is used for limiting the range of particles that exit the hall; if they leave the hall into the liner and then leave the liner without re-entering the hall then they are deemed uninteresting and no longer tracked.

HXY0 card

Usage: HXY0 x0 y0
The HXY0 card sets the center of the hall relative to the center of the detector. The (x0,y0) of the detector are at (0,0) in MARS coordinates and the hall might be offset from that.

VMAR card

Usage: VMAR xhalf yhalf zhalf
The VMAR card sets the size of the 'MARS' volume; this is the size of the "world". Sizes are given as half-lengths in cm. By default the world is very large. User changes are limited to no smaller that the size set by the VHAL + LTHK cards (or defaults).

NORF card

Usage: NORF inear
The NORF card sets whether the current configuration is interpreted as being in the Near Hall or Far Hall. Any negative value is taken as "Near".

NPLS card

Usage: NPLS nsup1 nsup2 ... nsupn 0
The NPLN card specifies the number of detector planes (or passive-active pairs) in each supermodule. This must be a multiple of the pair pattern length (the number of detector planes in each module) since fractional modules are never constructed; it will be adjusted downwards to fit so that NPairs = int(NModules) * int(NPairs/Module). Up to 15 supermodules (a hex digit) can be formed; a list shorter than the maximum is terminated by a value of zero. The length of this list limits the number of values interpreted for the other cards in this section.

SSPA card

Usage: SSPA up1 down1 up2 down2 ...
The SSPA card sets the additional spacing up- and downstream of the super-module. This allows space for winding coil cross connections and separates the super-mdoules. Each super-module has a pair of values associated with it.

SX0/SY0 cards

Usage: SX0 xoff1 xoff2 ...
Usage: SY0 yoff1 yoff2 ...
The SX0 (SY0) card specifies the x (y) offset of the super-module with respect to the centerline of the hall.

SiPA cards

Usage: SiPA 'pair' 'pair' 'pair' ... '....'
The SiPA card specifies the key and instance values for the passive and active planes in each pair. The i value runs from 1 to F (hex digit), allowing each super-module to have an independent configuration. For each super-module up to 16 pairs can be specified (lists shorter than 16 should be terminated by the string '....'). Each 4 character hollerith value is constructed, in order, from the key-passive, instance-passive, key-active, instance-active values (see Geometry.ddl for the description of the terms).

In the above example, the first super-module is constructed of modules each containing 4 C1 planes (concrete) each followed by a L1 limited-streamer tube detector. The second super-module has magnetized iron B4 planes, the first four have F4 liquid scintillator planes after them and the fifth is followed by at T1 (test/trigger) plane. The final super-module has a concrete planes, RPC's, magnetized iron planes, LST's, a (possibly) different type of magnetized iron planes and FLS planes.

SiRM cards

Usage: SiRM 'rotation-keys'
The SiRM card defines the rotation applied to the active partners in a module. Each super-module (i=1-9,A-F) is constructed of modules that may have different ordering for the rotations. There should be a single key (X,Y,U,V) for each pair defined in the module (see above for the description of the SiPA card).

SiX0/SiY0 cards

Usage: SiX0 xoff1 xoff2 ...
Usage: SiY0 yoff1 yoff2 ...
These card specifies the x and y offset of the planes in a module with respect to the centerline supermodule.

Cards affecting the magnet coils

CSET card

Usage: CSET coil_org1 coil_org2 ...
The CSET card specifies the arrangement of coil winding in the super-module. A preliminary mapping of index to arrangement is:
index description
0 no coils
1 center bus; return bus in (-x,-y) corner
4 center bus; return bus bars in 4 corners
8 center bus; return bus bars at 45degree intervals
10 "dipole configuration"; 4 bus bars at 50% of half-lengths, horizontal connections


Usage: CCUR coil_I1 coil_I2 ...
Usage: BFLD maxbfld
Usage: KATURN v1 v2 v3 ...
The CCUR card is a multiplier applied to the field returned by the field maps. Each super-module has an independent multiplier. By default the original map effectively focussed mu+ and defocussed mu-. This is reversed by setting the CCUR values to -1 (default). The BFLD sets the expected maximum field in kGauss (default 20 kGauss). The KATURN doesn't seem to do anything any more.


Usage: RMAG coil_radius
Usage: CMAG coil_clearance
The RMAG card determines the radius of the coil winding bus bars. The CMAG card is used to determine the clearance necessary between the cross connection bus bars on the front/back faces from the first/last module. If insufficient space (see SSPA card is allotted) then the cross connection are not inserted into the super-module. This means that 2*(coil_radius+coil_clearance) should be larger than the value given for either up or down in the SSPA card.


Usage: RCOL rmin rmax
Usage: NCOL 'material_name'
The RCOL and NCOL define an insulating collar that is inserted into the FLS and LST active planes at (x,y)=(0,0) of the plane. The two radii in the RCOL define the size of the annulus (depth is set by the plane size). The first 4 characters on the NCOL should match a defined material.

Cards to modify the plane geometry

The planes and, in the case of active detectors, their sub-components are initialized by nominal_pln_geom.F. This forms a base family of (1..9,A-Z) instances of each component to choose from. It may occur that none of the possibilities in a set is appropriate for a desired configuration. The following section describes a method of "tweaking" individual components away from their default values.

Cell-based geometries (LST,FLS,RPC)

For a given volume (a plane, extrusion, ...) there are associated attributes (to use ADAMO terminology) containing a value. The volume names use the key/instance for the first two characters.

Type Volume Name Description
PL Plane clipping volume
BXBox artifact for extrusion division (not user adjustable)
XTExtrusion divided out of BX volume
CBComb inserted into extrusion
CVCover inserted into extrusion
CLCell displaces comb, touches cover volume
GVGap Cover-side dead region between the cover and extrusion
GBGap Comb-side dead region between the comb and extrusion

extrusion cross-section image

In this figure:

Tiled geometries (Emu)

These planes are covered by tiles set on a rectangular grid.

Type Volume Name Description
PL Plane clipping volume
XTExtrusion (tile) uniformly distributed across PL area
CLCell inserted into XT
CVCover inserted into XT

Each tile is a XT volume and should be specified with a BOX shape and both a width and length. Embedded into the XT are one or two CL (active) volumes and optionally CV volumes. These a placed so that the CL (or CV) touches the z surface(s). The number of tiles is determined by what is allowed by integer numbers of XT volumes in each direction. An emulsion plane (E?PL) would be defined to be of the desired coverage size and made of air. Into that one inserts tiles (sheets) of backing plastic. The front (and back) surfaces of the plastic are then displaced by active cells of emulsion. If cover volumes are requested they displace only plastic, not emulsion.


These cards must are used to form a triplet connecting a volume, an attribute and a value. The real valued attributes must use the 'R' cards, the others use the 'I' cards. Tag names must be truncated to exactly four characters.
RVOL 'B7PL' 'B7PL' 'R7PL' 'R7PL' 'R7XT'
RVAL    40.    50.    40.    50.    40.

IVAL 'TUBE'     2
Tag Type Volume Description
SHAPe hollerith '??PL'
'BOX ', 'TUBE', 'PGON' (taken as an octogon)
'BOX ' only
MEDIum hollerith any first 4 characters of tracking medium name
WIDTh real any transverse size of volume
LENGth real any length of volume (used in BOX shapes)
THICkness real any depth of volume in z
AIR1gap real '??PL' extra space in z allotted for "waviness" on front side of plane
AIR2gap real '??PL' extra space in z allotted for "waviness" on back side of plane
BMAP integer 'B?PL' magnetic field map (0=none,1=old GUFLD).
CHILdren integer
# of sub-volumes
for the extrusion: 1=comb alone, 2=comb+cover, >2=+gaps
for the comb: this is the number of cells
DIGType integer '??PL'
digitization scheme (1=LST, 2=FLS, 3=RPC)
if >10, upper part modifies selected method


Controls whether TX planes (NearDet spectrometer) have bypass components (i.e. coil + collar) inserted into them. On (TRUE) by default for Daikon_01 and later (not possible before that, but effectively FALSE).

Materials and Tracking Parameters


Usage: FEPLDENSITY density
Usage: LIQD density
Usage: NDBEDROCKRHO density
Usage: GREENSTONERHO density
Set the steel plane, liquid scintillator, NDBEDROCK and GREENSTONE material densities.

ROCK and LINR materials

Usage: MARSTMED 'material name'
Usage: LINRTMED 'material name'
Set, by name, the material to be used for the MARS or LINR volumes. If the name is 'OLD ' or 'NEW ' use the following table:


Usage: ABSA Aelement1 Aelement2 ...
Usage: ABSZ Zelement1 Zelement2 ...
Usage: ABSW Wfraction1 Wfraction2 ...
Usage: ABSD absorber density
Usage: ABSN 'absorber-name'
This collection of cards allow the user to specify their own admixture of elements to create a material for using in 'Z' plane. Up to 10 elements can be combined; for each the user must specify the atomic A, Z and proportion by weight. End the list with a value of 0 if less than 10 elements are supplied.


Usage: LSTD density
Usage: LSTW argon co2 isobutane sf6 freon13B1
Usage: RPCD density
Usage: RPCW argon co2 isobutane sf6 freon13B1
These cards allow the user to change the composition and density of the gas mixture in the LST or RPC. The density must be specified in g/cm**3 (not g/liter). The proportions of the different gases is given by numbers of molecules (for ideal gases, and we'll assume they are, this means by volume). It is a good idea to explicitly set all the fractions (to zero if appropriate) if any are changed from the defaults.

Sxxx/Cxxx/Fxxx (xxx = LST,FLS,RPC,EMU,FE,PB,ROCK)

Usage: SXXX tmaxfd stemax deemax epsil stmin [idray iloss dcute dcutm]
Usage: CXXX cutgam cutele cutneu cuthad cutmuo bcute bcutm dcute dcutm ppcutm
Usage: PXXX pair comp phot pfis dray anni brem hadr munu dcay loss muls stra

These cards allow the user to modify (most of) the behaviours of GEANT while tracking in the LSTGAS MIXTURE, SCINT OIL (& PSTYRENE), RPCGAS MIXTURE, EMULSION, IRON, LEAD, ROCK (also used for DOLOMITE) tracking media.

Each media has three associated cards: the "S" card for tracking parameters (mostly step size); the "C" card for energy cutoffs; and the "F" card for physics flags. The "S" card retains the ability to modify limited "C" and "F" parameters based on it's previous functionality, but use of this feature is discouraged. The "S" and "C" cards take real values, while the "F" card takes integer values.


Tracking parameters:
  1. tmaxfd max. tracking step angle (degrees)
  2. stemax max. tracking step size (cm)
  3. deemax max. fractional energy loss per step
  4. epsil boundary crossing precision (cm)
  5. stmin min. step size (cm)
    old format:
  6. idray delta-ray production flag [integer]
  7. iloss energy loss mechanism flag [integer]
  8. dcute electron generated delta-ray cut
  9. dcutm muon generated delta-ray cut


Energy cutoff values (in GeV):
  1. cutgam cutoff for gammas
  2. cutele cutoff for electrons
  3. cutneu cutoff for neutral hadrons
  4. cuthad cutoff for charged hadrons
  5. cutmuo cutoff for muons
  6. bcute electron generated bremsstrahlung cut
  7. bcutm muon/hadron generated bremsstrahlung
  8. dcute electron generated delta-ray cut
  9. dcutm muon generated delta-ray cut
  10. ppcutm total energy cut for direct pair production by muons


Physics process flags (see [PHYS001]):
  1. pair pair production flag
  2. comp compton scattering flag
  3. phot photoelectric effect flag
  4. pfis photon induced nuclear fission flag
  5. dray delta-ray production flag
  6. anni positron annihilation flag
  7. brem bremsstrahlung flag
  8. hadr hadronic interactions flag
  9. munu muon-nucleus interaction flag
  10. dcay decay in flight flag
  11. loss continuous energy loss glag
  12. muls multiple scattering flag
  13. stra collision sampling energy loss in thin materials flag
Note: the SXXX parameters have no effect unless the AUTO 0 card is issued

Obsolete/removed cards

STDG card

Usage: STDG ilst ifls irpc iabs
   STDG 1 1 1 2
The STDG card specifies the sets from which instances of the components are chosen (or act as base families). Differents sets are available for LST, FLS, RPC and absorber planes. The default is all 1's (base setup for all components). If the value is negative the members of the family may not be modified by the means described below [now above].

As of 5/1/96 only one set for each type exists, and most rely on default values. The locking mechanism is also not yet in place. The actual available configurations can be gleaned from the values given in the routine nominal_pln_geom.F and an understanding of the format used as input to set_vol_par.F. This handling needs serious work and is high on the to-do list. Users who would like help modifying the geometry of planes or components of those planes should contact R. Hatcher ( for additional help.

This card was removed 10/10/96. Multiple lists/sets of default instances will not be supported. This cleans up the code and eliminates some confusing aspects.
Last modified: Thu Jul 5 18:44:49 CDT 2007