# Presentation: 268661

## Progress Report on GEANT Study of 

**Containerized Detectors**

-  Implement containerized detectors in GEANT.  Consider
- 1/3 XL and 2/3 XL sampling configurations.
-  Use  MINOS event generator, off-axis neutrino spectrum
-  Weight interaction vertex in GEANT by number of target
- nucleons in various materials
-  Parabolic fit to multiple tracks in an event.  Assume
-  longest track is electron.

- R. Ray
- 4/26/03

## GEANT Implementation

- 2.8 cm thick
- Wood Floor (not shown)

- Corner Blocks
- 10 x 10 x 10 cm3

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

- 6.06 x 2.49 x 2.44 m3
-    shipping container

- 2 mm thick steel skin

- Detector dimensions: 5.94 x 2.39 m2

## Consider two configurations:

- Absorber
- Polyethylene + air
- 1/3 XL, =0.70,
- 10 detector stations.

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

- Absorber
- Polyethylene + air
- 0.625 XL, =0.73,
- 6 detector stations.

- 1/3 radiation length sampling
- 2/3 radiation length sampling.

## 50 kton Detector

- 4 x 10 x 50 Stack of Containers

- x

- y

- z

- 15 cm horizontal and
- 20 cm vertical gaps
- between detectors in
- adjacent containers

- Cell Guides

- 50  kt of absorber
- 2.1 kt of steel
- 0.7 kt of wood
- 0.14 kt of Al.

## Weighted Neutrino Energy Spectra

- e CC

-  NC

- Flat neutrino spectrum
- generated between
- 0.5 - 3.5 GeV for e and
- 0.5 - 20 GeV for .
- Weight applied at analysis level.

## Event Reconstruction

- Essentially same as described yesterday by Leslie:
-  Hough Transform - step through slope and intercept space
-  Find best straight line fit.  Iterate.
-  Assign hits within  15 cm of fit to track.
-  Final parabolic fit to track.
-  Eliminate all but the first few hits on track from further
-      consideration
-  Repeat to look for additional tracks.

## e charged current

- e charged current

## e charged current

- e charged current

## e charged current

- e charged current

## e charged current

- e charged current

##   Neutral Current

-   Neutral Current

##   Neutral Current

-   Neutral Current

##   Neutral Current

-   Neutral Current

##  Neutral Current that Passes Cuts

-  Neutral Current that Passes Cuts

- ******2** of longest track in each view ****50
-  10 (6) or more hit planes in each view
-  Width of longest track (RMS) in each view < 5.5 cm2
******>******1.4 hits/plane ave for longest track, combined views
-  Fraction of hits on longest track/total hits****0.80, combined views
- 	(~ a fractional energy cut)
****35 - 105  (24 - 60) hits on longest track, combined views
- (Red indicates different cut for 2/3 radiation length sampling)

**CUTS**

- Calculate Figure of Merit = signal events/sqrt(e beam +  NC)
-       normalized to LOI flux for 50 kton detector

## 1/3 Radiation Length Sampling

- e CC

-  NC

- Cut distributions are
- weighted, successive

## 1/3 Radiation Length Sampling

- e CC

-  NC

- cm2

- cm2

- Cut distributions are
- weighted, successive

## 1/3 Radiation Length Sampling

- e CC

-  NC

- Cut distributions are
- weighted, successive

## 1/3 Radiation Length Sampling

- e CC

-  NC

- GeV

- GeV

- GeV

- GeV

- Cut distributions are
- weighted, successive

## 2/3 Radiation Length Sampling

- e CC

-  NC

- Cut distributions are
- weighted, successive

## 2/3 Radiation Length Sampling

- e CC

-  NC

- cm2

- cm2

- Cut distributions are
- weighted, successive

## 2/3 Radiation Length Sampling

- e CC

-  NC

- Cut distributions are
- weighted, successive

## 2/3 Radiation Length Sampling

- e CC

-  NC

- GeV

- GeV

- GeV

- GeV

- Cut distributions are
- weighted, successive

## 1/3 Radiation Length Sampling

|  | e CC* |  NC | e Center |  Center | e Beam |  Beam |
| --- | --- | --- | --- | --- | --- | --- |
| Total Events (weighted) | (467.8) | 89.7 | 487.4 | 90.6 | 487.3 | 82.7 |
| 2 < 50 | 408.9 | 30.2 | 444.0 | 31.9 | 364.8 | 26.4 |
| Nplanex,y  10 | 270.7 | 11.0 | 321.0 | 12.1 | 170.5 | 8.4 |
| Track width > 5.5 | 211.0 | 5.3 | 252.4 | 5.5 | 121.3 | 3.8 |
| Ave hits/plane  1.4 | 185.6 | 0.8 | 221.4 | 1.0 | 98.9 | 0.6 |
| Frac of hits on track > 0.80 | 156.8 | 0.2 | 184.0 | 0.12 | 82.9 | 0.13 |
| Hits on track bet 35-105 | 152.5 | 0.2 | 180.0 | 0.08 | 78.0 | 0.1 |
| Efficiency | 0.326 | 0.002 | 0.369 | 0.0009 | 0.160 | 0.001 |
| Number of Events (LOI, 50 kt) | 238.6 | 28.5 | 270.3 | 12.6 |  |  |
| FOM** | 32.6 |  | 44.1 |  |  |  |

-   * Events initiated in absorber
- ** Assumes 25 events from e in beam

## X

**X**

## 2/3 Radiation Length Sampling

|  | e CC* |  NC | e Center |  Center | e Beam |  Beam |
| --- | --- | --- | --- | --- | --- | --- |
| Total Events (weighted) | 472.8 | 82.4 | 487.4 | 79.0 | 486.7 | 73.4 |
| 2 < 50 | 349.2 | 17.9 | 384.4 | 21.2 | 250.6 | 15.1 |
| Nplanex,y  10 | 262.3 | 11.4 | 303.5 | 12.5 | 145.0 | 8.8 |
| Track width > 5.5 | 206.1 | 5.6 | 228.2 | 5.7 | 107.3 | 3.9 |
| Ave hits/plane  1.4 | 171.4 | 1.6 | 197.0 | 1.6 | 86.3 | 1.3 |
| Frac of hits on track > 0.80 | 142.8 | 0.58 | 165.2 | 0.4 | 72.5 | 0.49 |
| Hits on track bet 24-105 | 121.6 | 0.31 | 146.1 | 0.12 | 56.4 | 0.10 |
| Efficiency | 0.257 | 0.004 | 0.300 | 0.001 | 0.116 | 0.001 |
| Number of Events (LOI, 50 kt) | 188.3 | 53.6 | 219.4 | 20.7 |  |  |
| FOM** | 21.3 |  | 32.5 |  |  |  |

-  * Events initiated in absorber
- ** Assumes 25 events from e in beam

## Summary

-  Electron efficiency and background rejection attainable with containerized
-        detector appear reasonable, *but you do pay a price in electron efficiency.*
-  Background from structural elements negligible.
-  Difference between 1/3 XL and 2/3 XL sampling larger than in other analysis.
-        Requires more investigation.
- Still to do:
-  Simulate beam e and  CC
-  Add cross-talk (need a model) and RPC inefficiency
-  Final optimization of cuts
-  Generate new, high-statistics MC samples to smooth out peaks from large
-        weight events and obtain final results independent of training samples.
-  Categorize  NC events that pass cuts and e CC events that fail cuts.