1. Slide 1UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Rod Power Line Low-Pass Filter Study 3 August 2004 Sam Burke UCSB HEP Group

2. Slide 2UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Progress Noise on CERN Rod Test System à Power line is source per battery tests à 2.5 mV @ 1Mhz measured on Rod PS @UCSB Low Noise on UCSB Rod System à 1 - 2 A/D Counts

3. Slide 3UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Progress Inject Noise into UCSB system à introduce noise pulse train into 0.1 ohm resistor placed at common power supply point and observe system response. Frequency near Tracker Shaper Band. Reduce self-induced noise with filtering à Place Low Pass Filter on power line à Shaper Noise Band Defined –1/260ns =4Mhz to 1/40ns =25Mhz –>60dB attenuation in shaper band

4. Slide 4UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Low Pass Filter Schematic

5. Slide 5UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE LP Filter Response

6. Slide 6UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE LP Filter Test Results

7. Slide 7UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE LP Filter Break 2 power lines and common line and insert filter.

8. Slide 8UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Open Filter Issues Voltage drop à Vgnd=IR=19A*4.9mohms=93mV on Gnd à V+2.5=IR=12A*4.9mohms=60mV on 2.5V line Heat Generation à I^2R=19^2*.0049ohms=1.7 watts on Gnd coil à I^2R=12^2*.0049=0.7 watts on 2.5V line coil à I^2R=7^2*.0049=0.24 watts on 1.25V line coil Core Saturation in Machines Magnetic Field à Open core may saturate in field à Investigate toriod candidate

9. Slide 9UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Alternate Filter Approach Move filter outside of CMS magnetic enviornment à No saturation of filter inductors à Need to insert (splice) filter into Rod Power Cables Reduce heat generation by filter I^2 heating à Use lower winding resistance with a reduced noise attenuation if acceptable

10. Slide 10UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Alternate Inductor Impact

11. Slide 11UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Rod LP Filter Prototype High Current Inductors are on the two DC Power lines. Twisted pairs are power sense lines and analog sensor lines

12. Slide 12UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE LP Filter At Rod Pwr. Line

13. Slide 13UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Pulse Transformer

14. Slide 14UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Rod Module 1 Top: Noise injection of 10 ns pulse, 30 mhz, 10vpk into power supply common. Bottom: Low Pass Filter in Power Circuit

15. Slide 15UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Rod Module 3 (under CCU) Top: Noise injection of 10 ns pulse, 30 mhz, 10vpk into power supply common. Bottom: Low Pass Filter in Power Circuit

16. Slide 16UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Rod Module 6 Top: Noise injection of 10 ns pulse, 30 mhz, 10vpk into power supply common. Bottom: Low Pass Filter in Power Circuit à >40% reduction in noise à Normal UCSB background level is ~2.5 a/d counts

17. Slide 17UCSB CMS Weekly Status MeetingCMS Tracker Rod Filters Sam Burke EE Future Plans Create CERN like noise pattern à adjust frequency of pulser à can we filter this out? Study power supply sense-line filtering Test filter on CERN Rods that are experiencing high noise.