Presentation is loading. Please wait.

Presentation is loading. Please wait.

TOF Front End electronics

Similar presentations

Presentation on theme: "TOF Front End electronics"— Presentation transcript:

1 TOF Front End electronics
Reminder: TOF requirement Time Walk correction Open options Constant Fraction Discriminator Charge Measurement Time over Threshold Measurement Feb 2006 Jean-Sébastien Graulich

2 Jean-Sébastien Graulich
TOF Requirements Time resolution: 50-70 ps resolution -> Choice of TDC: CAEN V (25 ps LSB, >1000 Evt buffer) Particle rate ~ 2 MHz in TOF0 Charge measurement is not required Feb 2006 Jean-Sébastien Graulich

3 Jean-Sébastien Graulich
Time Walk Correction Timing is affected by the signal amplitude 2 Usual Solutions: Use Constant Fraction Discriminator (CFD) Measure amplitude and correct Time Walk Time Walk Correction Thresh. Time over threshold Example from Harp Feb 2006 Jean-Sébastien Graulich

4 Jean-Sébastien Graulich
Possible Options Option 1. Constant Fraction Discriminator (CFD) The time walk is corrected automatically in the discriminator Threshold value depends on the amplitude Advantage: Easy Cabling and No ADC Drawback No information at all on the charge (Energy Deposit) Cost: TDC + ~ 125 EUR/ch (CFD) BNC Cable PMT CFD TDC Trigger Logic Feb 2006 Jean-Sébastien Graulich

5 Jean-Sébastien Graulich
Possible Options Option 2. Measure the Charge with a QDC Advantage: More Precise and Good Charge Measurement Drawback General MICE ADC problem (No suitable QDC exists yet!) Requires Splitters More cabling Cost: TDC + ~ 125 EUR/ch (DISC) ~ 200 EUR/ch (QDC) ~ Delay Cables (~20 m/ch) (Assuming free splitters) Gate Signal PMT DISCRI Cable Delay TDC Trigger Logic Splitter QDC BNC Cable Feb 2006 Jean-Sébastien Graulich

6 Jean-Sébastien Graulich
Possible Options Option 3. Measure the Charge with any available Solution Same Advantages and Drawbacks as 2. Cost: TDC + ~ 125 EUR/ch (DISC) ~ ??? EUR/ch (ADC) ~ Delay Cables (~20 m/ch) (Assuming free splitters) Feb 2006 Jean-Sébastien Graulich

7 Rising edge + Trailing edge Time Measurement
Possible Options Option 4. Measure the Charge with Time Over Threshold Principle Advantage: Easy Cabling and Charge Measurement (not linear though) Good Precision for Time Walk Correction NINO = ASIC developed by CERN/MIC for Alice TOF Discriminator with ToT “proportional” to the Charge (at low amplitude) Proven technique, providing 50 ps resolution (IEE TNS Vol 51-5 (2004) ) Very Cheap: 2 EUR/ch Drawback Requires Board development ! Cost: TDC + Discri. board production (~50 EUR/ch) PMT NINO TDC Rising edge + Trailing edge Time Measurement Trigger Logic Width ~Charge Feb 2006 Jean-Sébastien Graulich

8 Jean-Sébastien Graulich
Plan Options 1. and 2. Will be tested in June/July at BTF Additional Test with TDC CAEN V775 to allow comparing with previous results (HARP) Options 3. and 4. are under investigation Feb 2006 Jean-Sébastien Graulich

Download ppt "TOF Front End electronics"

Similar presentations

Ads by Google