Definition of straw effective diameter Andrey Zinchenko 29
- Slides: 7
Definition of straw effective diameter Andrey Zinchenko 29. 01. 2010
Used data and procedure • It was used 2009 run pion data for CO 2/iso. C 4 H 10/CF 4 (90: 5: 5) with beam size in prototype about 10 mm and muon data for Ar. CO 2. • It was used the same tube in both cases. • It was used events with less or equal one hit per layer • Track was reconstructed using any 4 hits from 8, excluding investigated layer.
Pion tracks taken for analysis Straws # 6 5 2 1 5 31 29 15 25 11 30 29 22 9 27 18 5 1 Layer 6 (Aluminum) 2 19 21 Layer 1 (Aluminum) 17 3 22 23 14 21 7 15 19 6 25 26 13 11 23 10 1 10 9 26 13 2 7 27 14 3 6 3 30 31 4 17 18 Pion tracks taken for analysis Layer 7 (Gold) Layer 8 (Gold) beam
efficiency Definition of straw edges by approximation of the efficiency falls by straight lines (CO 2/iso. C 4 H 10/CF 4) Distance of track from the wire (cm)
efficiency Definition of straw edges by approximation of the efficiency falls by straight lines (Ar. CO 2) Distance of track from the wire (cm)
Effective diameter dependence from straw efficiency (red - CO 2/iso. C 4 H 10/CF 4, blue – Ar. CO 2)
Summary If we suppose that at the efficiency=50% the effective diameter is equal to real diameter of straw then for 100% efficiency the effective diameter of straw is decreased by about 300 µm in both cases (150 µm in radius)
