# Presentation: 863608

## GEANT Study of Electron ID and 0 Rejection for Containerized detectors

- Compare detectors in shipping containers to idealized continuous detector with no cracks
- Determine e and 0 id efficiency
- Use energy and angle information from MINOS MC for electrons and 0
- Only e and 0 produced.  No “underlying event”
- Use shipping container specifications provided by J. Cooper

- R. Ray
- FNAL
- 1/24/03

## GEANT Implementation

- Absorber
- Polyethylene + air
- 1/3 XL, =0.70

- Detector
- x, y readout
- at each station.
- 3 cm cells

- 2.8 cm thick
- Wood Floor

- Corner Blocks
- 20 x 20 x 20 cm3

- 5 cm x 5 cm box beams
- 1 cm wall thickness

- 6.06 x 2.59 x 2.44 m3
- shipping container

- 2 mm thick steel skin

## 3 x 8 x 33 Stack of Containers

- Gaps from
- corner blocks

- x

- y

- z

- Small vertical gaps
- between containers

## Kinematic Input Distributions

- “Oscillated” electrons

- “Non-oscillated” 0

- Distributions input to Geant
- Obtained from MINOS MC
-      (Courtesy of Debbie)
- Distributions not generated
- with 3 beam angle
- Vertices uniformly distributed
- in volume 10 x 10 x 60 m3
- about the center of the detector

## Analysis Cuts

- Number of hit counters > 20
- (~ proportional to energy cut)
- 1 hit in each of the first 3 planes with hits
- (look for min ionizing e before it showers)
- 40% of all hits in event lie in  4 cm road along shower axis in both views.

## Cuts, No Containers

- Red - e
- Green - 

## Cuts for Containerized Detectors

- Red - e
- Green - 

## Typical e Events in Containerized Detector

- Typical e Events in Containerized Detector

## Typical 0 Events in Containerized Detectors

- Typical 0 Events in Containerized Detectors

## Results

|  | e | 0 | e | 0 | e | 0 |
| --- | --- | --- | --- | --- | --- | --- |
| Events | 10000 | 10000 | 10000 | 10000 | 10000 | 10000 |
| Nhits>20 | 7614 | 2055 | 7409 | 1988 | 7477 | 1966 |
| 1 hit in first 3 planes | 6457 | 882 | 5602 | 585 | 5650 | 586 |
| Road cut | 5354 | 264 | 4388 | 164 | 4868 | 222 |

|  | No Container | Containerized
Same Cuts | Containerized,
Tuned Cuts** |
| --- | --- | --- | --- |

| electron eff. | 53.5% | 43.9% | 48.7% |
| --- | --- | --- | --- |

| S/N* | 20.3 | 26.8 | 21.9 |
| --- | --- | --- | --- |

- *   Not Properly normalized!
- ** Road Cut optimized

## Results

|  | e | 0 | e | 0 | e | 0 |
| --- | --- | --- | --- | --- | --- | --- |
| Events | 10000 | 10000 | 10000 | 10000 | 10000 | 10000 |
| Nhits>20 | 7348 | 1923 | 7267 | 1878 | 6861 | 1722 |
| 1 hit in first 3 planes | 5503 | 567 | 5367 | 554 | 4906 | 486 |
| Road cut | 4296 | 181 | 4196 | 178 | 3832 | 164 |

|  | Containerized
3 cm border | Containerized
6 cm border | Containerized
15 cm border |
| --- | --- | --- | --- |

| electron eff. | 43.0% | 42.0% | 38.3% |
| --- | --- | --- | --- |

| S/N* | 23.7 | 23.6 | 23.4 |
| --- | --- | --- | --- |

| e | 0 | e | 0 |
| --- | --- | --- | --- |
| 10000 | 10000 | 10000 | 10000 |
| 6006 | 1486 | 3942 | 946 |
| 4153 | 410 | 2597 | 235 |
| 3190 | 151 | 2029 | 95 |

| Containerized
30 cm border | Containerized
60 cm border |
| --- | --- |

| 31.9% | 20.3% |
| --- | --- |

| 21.1 | 21.4 |
| --- | --- |

- * Not Properly normalized!

## Conclusions

-  Effects from containers are noticeable
-  Do  not appear to be debilitating
-  Decreased Electron ID efficiency is primary effect rather
- than increase in background.
-  Before committing to a containerized solution the study
- 	should be extended to include a full event simulation