1. K. Andeen, U. Wisconsin, 6mTagger Calibration, DESY Summer Student Fest, Hamburg, GermanyApril 7, 2004 - 1 Calibration of the 6m Tagger Karen Andeen, University of Wisconsin DESY Summer Student Fest, Hamburg, Germany, April 7, 2004 Outline: Lumi Logistics Tagger Trauma Pedestal Problems Correct Calibration? Abbreviated Acknowledgements This talk will eventually be available on the web, somewhere. If you really want it and can’t wait, my e-mail address is kgandeen@mail.desy.dekgandeen@mail.desy.de

2. K. Andeen, U. Wisconsin, 6mTagger Calibration, DESY Summer Student Fest, Hamburg, GermanyApril 7, 2004 - 2 Lumi Logistics  Original System  γ Calorimeter (92.5m)  e Calorimeter (-27.5m)  New System  γ Calorimeter  Spectrometer  6m Tagger

3. K. Andeen, U. Wisconsin, 6mTagger Calibration, DESY Summer Student Fest, Hamburg, GermanyApril 7, 2004 - 3 Tagger Trauma  2000-initial calibration  2001-installation  2002-leak from cooling system  2003-6m removed and rebuilt  2004-tagger recalibration  Top: Damaged 6m Tagger  Left: Damaged Inside of 6m

4. K. Andeen, U. Wisconsin, 6mTagger Calibration, DESY Summer Student Fest, Hamburg, GermanyApril 7, 2004 - 4 Pedestal Problems  Raw Data Issues  Pedestal Extraction Options  Examination of Options  Mean and RMS  Time Variation  Beam Variation  Correlated Shifts? Channel 38: Number of Events vs. Energy (ADCs)

5. K. Andeen, U. Wisconsin, 6mTagger Calibration, DESY Summer Student Fest, Hamburg, GermanyApril 7, 2004 - 5 Mean & RMS Mean and RMS plot for same channel as before but selected for highest energy events on the right side of the tagger.

6. K. Andeen, U. Wisconsin, 6mTagger Calibration, DESY Summer Student Fest, Hamburg, GermanyApril 7, 2004 - 6 Time Variation Plot of pedestal means in adcs vs. channel number vs. (illegible) run number

7. K. Andeen, U. Wisconsin, 6mTagger Calibration, DESY Summer Student Fest, Hamburg, GermanyApril 7, 2004 - 7 Beam Variation Difference in pedestals for each channel by row between a pedestal run and a beam run selected for events without beam energy

8. K. Andeen, U. Wisconsin, 6mTagger Calibration, DESY Summer Student Fest, Hamburg, GermanyApril 7, 2004 - 8 Correlated Shifts Correlation Histograms: On the left is channel 50 (top left) plotted against itself, on the right is channel 50 plotted against channel 51

9. K. Andeen, U. Wisconsin, 6mTagger Calibration, DESY Summer Student Fest, Hamburg, GermanyApril 7, 2004 - 9 Correct Calibration?  Pedestals done  Calibrate the tagger using Sascha’s Spectacular Six-Step Sequence:  Subtract Pedestals  Select events with 50% of all energy in a certain column and two surrounding columns between 15-30% of all energy  Use x-position of column as a reference  Add energy of all cells in column and set a certain weight, N (not the actual energy, but should remain constant): N = Σcn  Plot N vs. n (weight for each of three middle cells in the column).  Hope for straight line by chi² minimization.  Find correspondence between N and actual energy (NOT actual energy, just relationship between certain slices).  Use the spectrometer such that KN = 27.52-E(spec) for a constant K.  Use only mean values of N and E(spec)  Now can use CΣKΣcn = 27.52 – E(spec)  Hope that C is the same no matter which position is chosen and that our data matches with the Spectrometer.

10. K. Andeen, U. Wisconsin, 6mTagger Calibration, DESY Summer Student Fest, Hamburg, GermanyApril 7, 2004 - 10 Abbreviated Acknowledgements  Special thanks to Tim Gosau who has found himself stuck finishing this project.  Thanks also to both Dorian and Tim for helping me learn ROOT and being patient with me when I’ve been very slow at thinking things through.  Last minute thanks to Wesley for help getting these plots to show up properly. The way I felt last night