RS counters in UMC
Takeshi K. Komatsubara (KEK-JPNS), since 2002.Nov.18
1. General Descriptions
The geometry of E949's RS(upto layer 19)_plus_BVL subsystem is set into UMC by calling GEOMRS1.
(The geometry of E787's RS (upto layer 21) subsystem is set into UMC by calling GEOMRS.)
Some important parameters on the geometry is stored in geomrs.cmn.
The initla geometrical parameters are determined in geodat.F with geopar.cmn.
2. "Cavity"
RS counters are located within "cavities" that are defined in GEOMRS1.
Cavity # 1: RS layers T,2,3,4,5
# 2: RS layers 6,7,8,9,10
# 3: (RSSC-1)
# 4: RS layers 11,12,13,14
# 5: (RSSC-2)
# 6: RS layer 15,16,17
# 7: RS layer 18,19
# 8: (BVL)
..
#12: (BVL)
#13: (blank)
- The thickness of each cavity is determined by TCAVBL(1-13).
- Al supports (corresponding Spier Web) are located between each cavity for RS.
2. Material in each "Cavity"
Remind that the RS counters in UMC are "pure" plastic-scintillators;
the counters are not wrapped in foil and there are no gaps between them.
All the gap is at the top and bottom of each module and is vacuum.
(Example) Cavity # 1: RS layers T,2,3,4,5
The thickness of Outer Clearance Gap is calculated
within GEOMRS1;
TCAVBL(1) - "sum of other parts" = 0.395625 cm > 0.0.
< Al support >
----------------------------------- ---
| Outer Clearance Gap (vacuum) | |
----------------------------------- |
| 5-counter (scintillator) | 1.905 cm |
----------------------------------- |
| 4-counter (scintillator) | 1.905 cm |
----------------------------------- |
| 3-counter (scintillator) | 1.905 cm | TCAVBL(1)=8.730 cm
----------------------------------- |
| 2-counter (scintillator) | 1.905 cm |
----------------------------------- |
| T-counter (scintillator) | 0.635 cm |
----------------------------------- |
| Inner Clearance Gap (vacuum) | 0.079375 cm |
---------------------------------- ---
< Al support >
^
|
| Charged Track from UTC
|
^
The analyses have looked at the stopping layer distribution of
Kpi2 and Kmu2 decay events and tried to match these up with the distributions from UMC data generated at different
range counter thicknesses.
The aim was to reproduce the Range distribution (and the stopping layer distribution)
of the real data by UMC and to estimate the UMC-based Trigger Acceptance in the RS correctly.
However, such determination does not necessarily reproduce the Energy distribution in each of
the RS counters in the same time.
Suppoer a muon track that stops in the (invisible) material between Layer 15 and 16;
the stopping layer in the RS is 15 in this case and, to reproduce the stopping layer distribution,
the RS thickness in UMC should be set to be **larger** than the real thickness,
which follows the the energy deposit in each counter in UMC is **larger** than the real case.
4. Furure plan: realistic RS ??
< Al support >
-----------------------------------
| Outer Clearance Gap (vacuum) | <--- much thinner than before
-----------------------------------
| ////// wrapping & air ///// |
-----------------------------------
| 5-counter (scintillator) |
-----------------------------------
| ////// wrapping & air ///// |
-----------------------------------
| 4-counter (scintillator) |
-----------------------------------
| ////// wrapping & air ///// |
-----------------------------------
| 3-counter (scintillator) |
-----------------------------------
| ////// wrapping & air ///// |
-----------------------------------
| 2-counter (scintillator) |
-----------------------------------
| ////// wrapping & air ///// |
-----------------------------------
| T-counter (scintillator) |
-----------------------------------
| ////// wrapping & air ///// |
-----------------------------------
| Inner Clearance Gap (vacuum) |
----------------------------------
< Al support >
^
|
| Charged Track from UTC
|
^
Last modified by T.K.Komatsubara(KEK), Mon Nov 18 18:46:54 JST 2002