Infrared spectroscope for electron bunch length measurement: Heat sensor parameters Analysis

1. Infrared spectroscope for electron bunch length measurement: Heat sensor parameters Analysis Gilles Dongmo – M. SULI Presentation August 11, 2011

2. The detector • The detector used for the project is a piezoelectric detector made of Lead ZirconateTitanate(PZT) • 128 pixels arranged over 14.3 mm

3. The printed board circuit Power connector USB connector • The detector is mounted to a printed circuit board • Pin 3 of the synchronization connector out puts a pulse • The connector TP3 out puts the signal response of the detector Synchronization connector (pin 3) Sensor connected Output detector signal

4. The initial data collected • The detector is lit at the middle pixels • maybe the detector was sending out an inverted signal. • Pixels 68 and 95 are dead.

5. What type of noise do we have to deal with? • Data were recorded for frequencies up to 250 Hz • The signal to noise ratio was found to be high • We get an average signal to noise ratio of 43.3 • The detector is not very sensitive to the room’s light and other background noise.

6. Data collection • The read rectangles represent the maximum and minimum values averaged over 12 sampling • The green line is the current reading. • Some pixels are dead. • How is the software using the raw data? Dead pixel

7. The AC-Coupling issue • The next step was to try to figure out what type of data were actually collected by the detector which meant we had to understand how the data were collected. • We were able to write a program replicating the data received by the software. The algorithm they used did not seem to present any issue if the data the detector was outputting was the light intensity read by it when the light was on and off

8. Tape at the middle of the detector Dead pixel reading

9. Intensity of the signal

10. Detector’s response time • Generated signal and integration time. On this graph from the detector’s user’s manual, the integration time covers most of the signal period both the on and off phase. Dead time

11. The integration time data Experimental integration time Calculated integration time

12. Comparison of the integration times • The plot shows the calculated integration time is very constant over this range frequencies. • The delay drops with frequency

13. The equipment setup

14. Single cell detector and Infrared laser • Single cell piezoelectric detector. • Sensitivity calculated to be 1.34 micro-amps per watt. • This was done with the red HeNe laser.

15. Sensitivity calculation • The amount of power generated by the laser was recorded using a power meter • The chopper wheel created the pulse • The lens focused the beam as much as possible

16. Current output determination

17. Acknowledgements This was done with the appreciated contribution of: • Josef Frisch • Alan Fischer • Kiel Williams • Julie Cass • Mark Petree • Georges Burgueno • ToneeSmith • The Department of Energy • SLAC & SULI staff

18. Thank you!!