1. J. Vandenbroucke N. Bramall, M.D’Agostino, A. Morey, P. Sandstrom, M.Solarz, I.Taboada Calibration of the Standard Candle: How Standard Is It? IceCube Collaboration Meeting, Baton Rouge, April 10, 2006

2. J. Vandenbroucke Baton Rouge April 10, 2006 Motivation An IceCube calibration source whose absolute intensity is known precisely for each pulse Extend the flasher energy range to cover IceCube’s high end Simulate high energy cascades to test cascade energy and direction reconstruction Combine with Golden DOM’s for a complete well-calibrated chain

3. J. Vandenbroucke Baton Rouge April 10, 2006 Components Pressure Vessel Optics Laser Electronics

4. J. Vandenbroucke Baton Rouge April 10, 2006 Laser Heating Tape Nitrogen Laser 337 nm 4 ns pulse 30 Hz internal power meter adjustable filter wheel

5. J. Vandenbroucke Baton Rouge April 10, 2006 Optics Design

6. Optics Implementation

7. Cherenkov-Sculpting Cone Cerenkov-Sculpting Cone

8. J. Vandenbroucke Baton Rouge April 10, 2006 Software Data Stream: pulse number mSec timestamp: pmt mSec timestamp: laser internal power pmt DAQ dark current pmt DAQ actual current pmt DAQ temperature

9. J. Vandenbroucke Baton Rouge April 10, 2006 The First Standard Candle Deployed on String 40 Between 40-22 and 40-23

10. J. Vandenbroucke Baton Rouge April 10, 2006 The First Standard Candle Deployed on String 40 Between 40-22 and 40-23

11. J. Vandenbroucke Baton Rouge April 10, 2006 Calibration Specifics: Optics We can “bypass” the extinction in the optics by using an absolute calibration of the PMT and the laser’s internal power meter Extinction due to cone: Extinction due to window:

12. J. Vandenbroucke Baton Rouge April 10, 2006 Calibration Specifics: Obstructions 1) main cable 2) support vanes for cone 3) steel support cables obstructions not aligned  sum extinctions

13. J. Vandenbroucke Baton Rouge April 10, 2006 Calibration Specifics: Obstructions 1) main cable combine two cases Extinction due to main cable:

14. J. Vandenbroucke Baton Rouge April 10, 2006 Calibration Specifics: Obstructions 2) cone support vanes Extinction due to vanes:

15. J. Vandenbroucke Baton Rouge April 10, 2006 Calibration Specifics: Obstructions 3) steel support cables Extinction due to steel cables:

16. J. Vandenbroucke Baton Rouge April 10, 2006 Two independent, calibrated internal energy measurements: PMT & power meter Plot not available (en route from Pole) PMT calibrated for filter wheel settings 50% and 5% (calibration to +/- 10%) (1) (2)

17. J. Vandenbroucke Baton Rouge April 10, 2006 Calibration Conclusions and Preliminary Calibration: Total extinction: Per-pulse Energy: For details, see Standard Candle Calibration and other SC documents: http://docushare.icecube.wisc.edu/docushare/dsweb/View/Collection-1152

18. The Future: Burning Brightly More to come from the Standard Candleshop Next year: point down (between DOM’s 12 and 13), 20x brighter Later: point sideways (with cone removed?)