1. ......... PMT x y BATATA in the Lab.... Simulation parameters must be tuned with measurement. Key parameters: 1) Attenuation length by the WLS fiber 2) Light yield in the per energy deposition unit

2. BATATA planes response Bicron specifications BCF-92: 1/e Length > 350 cm N phe (x) = Edep Yield(l) Ceff(l) Qeff(l) Att(x) Att(0 cm) = 1 Yield(l) Ceff(l) Qeff(l)  k (cte) = / Att(x) 1Fiber = 4-6 phe/MeV 2Fibers = 5-8 phe/MeV  2 MeV A measure of N phe (x 0 ) is necessary to determine

3. 2 Fiber at 350 cm from PMT: Median 8.5 phe MPV 5.3 phe 1 Fiber at 350 cm from PMT: Median 6.4 phe MPV 4.6 phe BATATA planes response

4. Expected mean number of phe at 350 cm assuming that Nphe(150cm) is the true value: expected = Att(350cm) / Att( 150cm) measured  7.8 (4.6) ( expected - measured ) / measured  20-30% 2 Fiber at 150 cm from PMT: Median 11.0 phe MPV 6.5 phe BATATA planes response

5. 2 Fiber at 150 cm from PMT 2 Fiber at 350 cm from PMT 1 Fiber at 350 cm from PMT

6. Towards a full understanding of BATATA planes response.... 1 Fiber at 260 cm, 170 cm and 70 cm rom PMT: Median(phe) MPV(phe) 10.36.8 6.30 4.00 5.003.19 using k = 4.2 phe/MeV Conversion factor 1phe  25-30 QADC

7. Gracias....