1. OD Calorimetry Study Update — Leakage Effect and slot optimization Jaewon Park University of Rochester MINERvA/Jupiter Group Meeting, June 21, 2006

2. 2 Contents Leakage study  OD geometry used Original: 5.75—5.72—5.72—11.43cm 5.75cm x 25 layers 2.5cm x 25 layers  5.72 cm x 5,10,15,20,25 layers  2.5 cm x 5,10,15,20,25 layers  5.72 cm x 6,7,8,9 layers added to see gap between 5 layers and 10 layers  2.5 cm x 11,12,13,14 layers added similarly Slot optimization  Original: 5.72 —5.72—5.72—11.43—(17.15)cm  5.72 —5.72—11.4—11.43—(11.43)cm Total volume kept constant  5.72 —11.43—11.43—11.43—(5.72)cm Structural support layer

3. 3 Same color and symbol are used for two groups:  5.72cm x 5, 10, 15, 20, 25 layers  2.5cm x 5, 10, 15, 20, 25 layers For 5.72cm geom, more layers didn’t affect much on resolution without leakage effect. 2.5cm geom shows better resolution than 5.72cm geom For 5.72cm geom, leakage is almost eliminated when more than 10 layers are used. Uncalibrated resolution wasn’t affect much by increasing more layers Dependence of number of OD layers - Previous data

4. 4 Dependence of number of OD layers - 5.72cm x 5, 6,7,8,9,10, 15, 20, 25 layers Same color and symbol are used for two groups:  5.72cm x 5, 6,7,8,9,10, 15, 20, 25 layers  2.5cm x 5, 10, 15, 20, 25 layers For 5.72cm geom, leakage changes gradually between 5 and 10 layers 5 6 7 8 10 layers 15,20,25

5. 5 Same color and symbol are used for two groups:  5.72cm x 5, 6,7,8,9,10, 15, 20, 25 layers  2.5cm x 5, 10, 15, 20, 25 layers For 5.72cm geom, leakage changes gradually between 5 and 10 layers 10 11 12 13 15 layers 20,25 Dependence of number of OD layers - 2.5cm x 5, 10,11,12,13,14,15, 20, 25 layers

6. 6 5.72—5.72—5.72—11.43—(17.15)cm(Original conf) 5.72—5.72—11.43—11.43—(11.43)cm 5.72—5.72—11.43—11.43—(5.72)cm Reducing thickness of most outer layer increase total OD thickness  Hoping reducing leakage Need to know what is the allowed minimum thickness without causing mechanical or background particle shielding problem etc. Different slot position

7. 7 Summary 5.72cm x 5 layers is similar to current OD configuration 5.72cm x 6 layers wouldn’t affect much  With current calibration scheme, utilizing last outer supporting layer won’t help greatly as we hope Need to specify minimum thickness of most outer layer