(1) In ../src/mum/mutrst.f, these are the calls made to GSDET, which are supposed to describe the path from the top (HALL) down to each of the sensitive volumes. Many odd things here, including undefined strings, lines not starting with HALL, and apparently not enough lines.  
(2) Here is the tree for HALL>MUA1>MS12. MS12 and MZ12 make up station 2 North, as can be seen below. Only the paths underlined in red correspond to paths in the calls to GSDET.  
(3) Here is the tree for MZ12. Only the paths underlined in green correspond to paths in the calls to GSDET.  
(4) OK, different approach: These are the volumes that in the code are called 'active'.  
(5) And the full paths of these volumes are: HALL + MUA1 + MS11  MQ11 + MN11  MO11 + MU11 station 1 N    + MT11   + MN12  MO12 + MU12    + MT12   + MN13  MO13 + MU13   + MT13  + MZ12  MQ12 + MX21  MY22  MU23 station 2 N   + MX22  MY22  MU22   + MX23  MY23  MU23    + MS12  MP12 + MN21  MO21  MT21   + MN22  MO22  MT22   + MN23  MO23  MT23    + MS31  MQ31 + MN31  MO31  MT31 station 3 N  + MN32  M032  MT32  + MUA2 + MS21  MQ21 + MN41  MO41 + MU41 station 1 S   + MT41  + MN42  MO42 + MU42  + MT42  + MZ22  MQ22 + MX51  MY51  MU51 station 2 S  + MX52  MY52  MU52  + MX53  MY53  MU53  + MS22  MP22 + MN51  MO51  MT51  + MN52  MO52  MT52  + MN53  MO53  MT53  + MS23  MQ23 + MN61  MO61  MT61 station 3 S + MN62  MO62  MT62  
(6) Next: MuID. Here are all the volumes constructed in the MuID code. Note they include the DX magnets.
Here the sensitive volumes are highlighted in red:
HALL → MUSD → MUSH → MUGSThere are 10 copies of MUSD. MUSH and MUGS have the same dimensions as MUSD. We discovered a 6th detector plane behind MuID South Station 5. After removing this, we have vol copy ipl z  MUIDENT 1: MUSD 1 1 695.8 MUIDENT 2: MUSD 7 1 699.8 MUIDENT 3: MUSD 2 2 737.1 MUIDENT 4: MUSD 8 2 737.1 MUIDENT 3: MUSD 3 3 774.9 MUIDENT 4: MUSD 9 3 774.9 MUIDENT 3: MUSD 4 4 824.5 MUIDENT 4: MUSD 10 4 824.5 MUIDENT 3: MUSD 5 5 870.0 MUIDENT 4: MUSD 11 5 870.0 muident  Muon hole installed at z= 975.500 muident  Muid planes placed at following Z 695.750 737.100 774.900 824.500 870.000 muident  Muon_Identifier installed  
(7) Hits are shown for all MuID planes. There is a small cluster of hits in the center. This is caused by the geom definitions: The sensitive volumes span the full height and width of MuID (black), and around the center a square hole (MUHL, in magenta) is defined, which holds the DX magnets among other things. Down the center line of MUHL a space is left out for the beam pipe. This ~4×4cm space reverts to being active volume. Both MUHL and the MUSD volumes are placed in HALL. They overlap (by design), but they are not defined as 'multi', and are not flagged by the overlap checker. Why not???  
(8) BBC: the BBC sits near the center, along the beamline. The senitive volumes are in black: The paths to the sensitive volumes are: HALL → BBCM(2) → BBCD(64) → BBCQ  
(9) Paths to the sensitive volumes SISN for the VTX, with the max copy number for each volume: HALL(1) SIEN(1) SICG(1) SI01(10) SISN(4) HALL(1) SIEN(1) SICG(1) SI02(20) SISN(4) HALL(1) SIEN(1) SICG(1) SI03(16) SISN(5) HALL(1) SIEN(1) SICG(1) SI04(24) SISN(6)Paths to the sensitive volume SISI for FVTX, with the max copy number for each volume: HALL(1) SIEN(1) SICG(1) SCMS(1) SCM1(1) SI05(1) SIPB(24) SISB(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMS(1) SCM1(1) SI07(1) SIPB(24) SISB(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMS(1) SCM1(1) SI09(1) SIPB(24) SISB(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMS(1) SCM1(1) SI11(1) SIPS(24) SISS(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMS(1) SCM2(1) SI06(1) SIPB(24) SISB(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMS(1) SCM2(1) SI08(1) SIPB(24) SISB(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMS(1) SCM2(1) SI10(1) SIPB(24) SISB(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMS(1) SCM2(1) SI12(1) SIPS(24) SISS(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMN(1) SCM3(1) SI13(1) SIPS(24) SISS(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMN(1) SCM3(1) SI15(1) SIPB(24) SISB(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMN(1) SCM3(1) SI17(1) SIPB(24) SISB(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMN(1) SCM3(1) SI19(1) SIPB(24) SISB(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMN(1) SCM4(1) SI14(1) SIPS(24) SISS(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMN(1) SCM4(1) SI16(1) SIPB(24) SISB(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMN(1) SCM4(1) SI18(1) SIPB(24) SISB(1) SISI(2) HALL(1) SIEN(1) SICG(1) SCMN(1) SCM4(1) SI20(1) SIPB(24) SISB(1) SISI(2) gugeom  finished SVX  
(10) The MPC gave a fatal error in G4. The MPC consists of a holder volume (UP1S for station 1 South), with a gas volume inside (UG1S), and 2 sheets of 'S2glassepoxy'. These sheets were defined with zero thickness, and one of them was placed outside of the mother volume. Fixed the zerothickness bug in MuonPadGeom_vol.f, though the total mass is not yet properly represented.  
(11) Volume conflicts seen: MUID: = Overlap ov00000: MUHL extruded by: MUHL/DXTF_1 ovlp=1.05975 = Overlap ov00001: LHUM extruded by: LHUM/DXTF_1 ovlp=1.05975 = Overlap ov00002: MUHL/SFLO_1 overlapping MUHL/EDXM_2 ovlp=5.43333 = Overlap ov00003: LHUM/SFLO_1 overlapping LHUM/EDXM_1 ovlp=5.43333 = Overlap ov00004: LHUM/SFLO_1 overlapping LHUM/SDXM_1 ovlp=4.87366 = Overlap ov00005: MUHL/SFLO_1 overlapping MUHL/SDXM_1 ovlp=4.87366 = Overlap ov00006: LHUM/SFLO_1 overlapping LHUM/SSDX_1 ovlp=4.035 = Overlap ov00007: MUHL/SFLO_1 overlapping MUHL/SSDX_1 ovlp=4.035 MUTR: = Overlap ov00008: MUA2/OC2E_1 overlapping MUA2/MS23_1 ovlp=1.16678 = Overlap ov00009: MUA1/E2CO_1 overlapping MUA1/MS13_1 ovlp=0.228251 = Overlap ov00010: MO42/MB21_1 overlapping MO42/MT42_1 ovlp=0.151339 = Overlap ov00011: MO41/MB21_1 overlapping MO41/MT41_1 ovlp=0.151339 = Overlap ov00012: MO43/MB21_1 overlapping MO43/MT43_1 ovlp=0.151339 = Overlap ov00013: MO13/MB11_1 overlapping MO13/MT13_1 ovlp=0.151339 = Overlap ov00014: MO12/MB11_1 overlapping MO12/MT12_1 ovlp=0.151339 = Overlap ov00015: MO11/MB11_1 overlapping MO11/MT11_1 ovlp=0.151339 BEAMPIPE: = Overlap ov00016: HALL/MUA1_1 overlapping HALL/PIP3_1 ovlp=0.07 = Overlap ov00017: HALL/MUA2_1 overlapping HALL/PIP3_2 ovlp=0.07 = Overlap ov00018: HALL/EXT6_1 overlapping HALL/BE14_1 ovlp=0.05 = Overlap ov00019: HALL/EXT3_1 overlapping HALL/BE03_1 ovlp=0.05 = Overlap ov00020: HALL/EXT7_1 overlapping HALL/BE07_1 ovlp=0.05 = Overlap ov00021: HALL/EXT7_1 overlapping HALL/BE08_1 ovlp=0.05 = Overlap ov00022: HALL/EXT7_1 overlapping HALL/BE15_1 ovlp=0.05 = Overlap ov00023: HALL/EXT7_1 overlapping HALL/BE16_1 ovlp=0.05 = Overlap ov00024: HALL/EXT2_1 overlapping HALL/BE01_1 ovlp=0.05 = Overlap ov00025: HALL/EXT2_1 overlapping HALL/BE02_1 ovlp=0.05 = Overlap ov00026: HALL/EXT6_1 overlapping HALL/BE13_1 ovlp=0.05 = Overlap ov00027: HALL/EXT3_1 overlapping HALL/BE04_1 ovlp=0.05 = Overlap ov00028: HALL/EXT3_1 overlapping HALL/BE11_1 ovlp=0.05 = Overlap ov00029: HALL/EXT3_1 overlapping HALL/BE12_1 ovlp=0.05 = Overlap ov00030: HALL/EXT2_1 overlapping HALL/BE10_1 ovlp=0.05 = Overlap ov00031: HALL/EXT2_1 overlapping HALL/BE09_1 ovlp=0.05 = Overlap ov00032: HALL/EXT6_1 overlapping HALL/BE05_1 ovlp=0.05 = Overlap ov00033: HALL/EXT6_1 overlapping HALL/BE06_1 ovlp=0.05 = Overlap ov00034: HALL/PL01_1 overlapping HALL/BA01_1 ovlp=0.02 = Overlap ov00035: HALL/PL04_1 overlapping HALL/BA07_1 ovlp=0.02 = Overlap ov00036: HALL/PL04_1 overlapping HALL/BA08_1 ovlp=0.02 = Overlap ov00037: HALL/PL04_1 overlapping HALL/PL12_1 ovlp=0.02 = Overlap ov00038: HALL/PL05_1 overlapping HALL/BA09_1 ovlp=0.02 = Overlap ov00039: HALL/PL05_1 overlapping HALL/BA10_1 ovlp=0.02 = Overlap ov00040: HALL/PL05_1 overlapping HALL/PL13_1 ovlp=0.02 = Overlap ov00041: HALL/PL06_1 overlapping HALL/BA11_1 ovlp=0.02 = Overlap ov00042: HALL/PL06_1 overlapping HALL/BA12_1 ovlp=0.02 = Overlap ov00043: HALL/PL06_1 overlapping HALL/PL14_1 ovlp=0.02 = Overlap ov00044: HALL/PL07_1 overlapping HALL/BA13_1 ovlp=0.02 = Overlap ov00045: HALL/PL07_1 overlapping HALL/BA14_1 ovlp=0.02 = Overlap ov00046: HALL/PL07_1 overlapping HALL/PL15_1 ovlp=0.02 = Overlap ov00047: HALL/PL08_1 overlapping HALL/BA15_1 ovlp=0.02 = Overlap ov00048: HALL/PL08_1 overlapping HALL/BA16_1 ovlp=0.02 = Overlap ov00049: HALL/PL08_1 overlapping HALL/PL16_1 ovlp=0.02 = Overlap ov00050: HALL/PL03_1 overlapping HALL/PL11_1 ovlp=0.02 = Overlap ov00051: HALL/PL03_1 overlapping HALL/BA06_1 ovlp=0.02 = Overlap ov00052: HALL/PL03_1 overlapping HALL/BA05_1 ovlp=0.02 = Overlap ov00053: HALL/PL02_1 overlapping HALL/PL10_1 ovlp=0.02 = Overlap ov00054: HALL/PL01_1 overlapping HALL/BA02_1 ovlp=0.02 = Overlap ov00055: HALL/PL02_1 overlapping HALL/BA04_1 ovlp=0.02 = Overlap ov00056: HALL/PL02_1 overlapping HALL/BA03_1 ovlp=0.02 = Overlap ov00057: HALL/PL01_1 overlapping HALL/PL09_1 ovlp=0.02 = Overlap ov00058: SP04/SIK3_25 overlapping SP04/SICL_13 ovlp=0.01905 = Overlap ov00059: SP04/SIK3_25 overlapping SP04/SICL_12 ovlp=0.01905 = Overlap ov00060: SP03/SIK3_4 overlapping SP03/SICL_1 ovlp=0.01905 = Overlap ov00061: SP03/SIK3_4 overlapping SP03/SICL_2 ovlp=0.01905 = Overlap ov00062: MUA2/TSIP_1 overlapping MUA2/FINS_1 ovlp=0.0174373 = Overlap ov00063: HALL/EXT6_1 overlapping HALL/BE23_1 ovlp=0.015 = Overlap ov00064: HALL/EXT2_1 overlapping HALL/BE21_1 ovlp=0.015 = Overlap ov00065: HALL/EXT2_1 overlapping HALL/BE17_1 ovlp=0.015 = Overlap ov00066: HALL/EXT3_1 overlapping HALL/BE18_1 ovlp=0.015 = Overlap ov00067: HALL/EXT3_1 overlapping HALL/BE22_1 ovlp=0.015 = Overlap ov00068: HALL/EXT7_1 overlapping HALL/BE24_1 ovlp=0.015 = Overlap ov00069: HALL/EXT7_1 overlapping HALL/BE20_1 ovlp=0.015 = Overlap ov00070: HALL/EXT6_1 overlapping HALL/BE19_1 ovlp=0.015  
(12) Stray hits are seen outside of the (F)VTX volume. There is a shell of them ar a radius of 28 cm, in the central arm area.  
(13) In Pisa, a cross section at z=0 shows no objects at 28cm. The objects further out are Ibeams of the (former) HBD support. Solution: The stray hits were located at positions 5.5× further out than real hits. This had to do with a cm→mm missing conversion when calculating the average of (x_{in}+x_{out})/2, because (1cm + 1mm)/2 = 5.5mm.  
(14) 'Unsplit' some of the FVTX volumes: the reason is that we saw (some, but not all) missing hits in some wedges at the edge of the halfdisks. We suspected that ovelapping volumes, though properly declared, might still cause trouble. Removing the East cages confirmed that all hits in the West cages now are registered properly. In the figure, you can see the South arm holder volume SCMS in black. Inside SCMS, there are 2 holder volumes SCM1 and SCM2 to hold the SW and SE cages, respectively. In the figure, you can see SCM1 in green. SCM1 contains the four station disks SI5,7,9,and 11. Holder volume SI05 is shown in black. SCM1 overlaps with SCM2, ans SI056 overlap, as well as SI078, SI0910 and SI1112.  
(15) Now the halfdisks are placed directly into the South cage (East halfdisks are not shown). All hits now appear in the G4 output, even though we still have overlapping volumes SI056 etc. HALL SIEN SICG SCMS DUMM SI05 SIPB SISB SISI HALL SIEN SICG SCMS DUMM SI07 SIPB SISB SISI HALL SIEN SICG SCMS DUMM SI09 SIPB SISB SISI This is the new volume HALL SIEN SICG SCMS DUMM SI11 SIPS SISS SISI hierarchy. Note that HALL SIEN SICG SCMS DUMM SI06 SIPB SISB SISI SCM14 have been replaced HALL SIEN SICG SCMS DUMM SI08 SIPB SISB SISI by DUMM, in order to keep HALL SIEN SICG SCMS DUMM SI10 SIPB SISB SISI the DIGI code and offline HALL SIEN SICG SCMS DUMM SI12 SIPS SISS SISI code the same. HALL SIEN SICG SCMN DUMM SI13 SIPS SISS SISI HALL SIEN SICG SCMN DUMM SI15 SIPB SISB SISI HALL SIEN SICG SCMN DUMM SI17 SIPB SISB SISI HALL SIEN SICG SCMN DUMM SI19 SIPB SISB SISI HALL SIEN SICG SCMN DUMM SI14 SIPS SISS SISI HALL SIEN SICG SCMN DUMM SI16 SIPB SISB SISI HALL SIEN SICG SCMN DUMM SI18 SIPB SISB SISI HALL SIEN SICG SCMN DUMM SI20 SIPB SISB SISI  
(16) Outstanding issues:
