1 / 9

The ADC Problem in MICE

The ADC Problem in MICE. Reminder: Spill, Readout and Digitization Acquisition Rate vs dead time Conventional ADC vs Flash ADC Stretcher and Sampling frequency Commercial Flash ADCs Charge measurement without ADC ?. Reminder. Main Requirement from the MICE proposal

rudyard-bentley
Download Presentation

The ADC Problem in MICE

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The ADC Problem in MICE • Reminder: Spill, Readout and Digitization • Acquisition Rate vs dead time • Conventional ADC vs Flash ADC • Stretcher and Sampling frequency • Commercial Flash ADCs • Charge measurement without ADC ? Jean-Sébastien Graulich

  2. Reminder • Main Requirement from the MICE proposal • The aim is to collect data for 600 muons/Spill • A spill is 850 µs long (flat top of the RF) • First Principle: Readout of Detector Data at the end of the Spill • DAQ-trigger is given by the End of Spill Signal • Data for ~600 muons has to be buffered in the Front End Electronics • Particle-trigger (or strobe) is given when a particle go through MICE • Digitization dead time will limit the number of muons we can collect Jean-Sébastien Graulich

  3. #events vs dead time • 850 microsecond RF Flat top • Multiple events per burst rejected Jean-Sébastien Graulich

  4. ADC <-> Flash ADC • Conventional ADC (currently on the market) • 1 datum/ch = charge (~12 bits) • Dead time > 2.8 µs w/o zero suppression • Given by the conversion time • Buffer size ~ 30 events • Would be enough if zero suppression but then the Dead Time is longer • Flash ADC = Waveform digitizer • The signal is digitized with given sampling frequency and resolution • Many data points/ch (~ 12 bit each) • Charge reconstructed by software • Direct signal from PMt-> requires ~ 300 MHz Sampling f • Dead time given by access to the buffer memory (<< µs) • Buffer size: up to 1MSample/ch Q Gate ~ 100 ns ~ 30 ns Jean-Sébastien Graulich

  5. Stretcher • Problem 1: $ High frequency Flash ADC are expensive: 1000 EUR/ch • Problem 2: Data volume • 20 samples/ch/muon • No zero suppression (keep low dead time) • 600 µ x 240 ch x 20 sample x 12 bits = 4.2 MB/Spill • Solution 1: Stretcher -> Reduce sampling frequency Stretcher V ~ Q ~ 300 ns Jean-Sébastien Graulich

  6. Commercial Flash ADCs • TPG (Alice) flash ADC looks out of specs • Sampling frequency 10 MHz • 1 kSample buffer (100 µs) • Commercial Flash ADC • Struck SiS3300: 8 Ch, 1-100 MHz, 12-bit, 128 kSample/ch • ~3500 EUR/board • http://www.struck.de/sis3300.htm • Hytec VTR2537: 8 Ch, 60 MHz, 12-bit, 1 MSample/ch • < 4500 EUR/board • http://www.hytec-electronics.co.uk/2537.html • Still expensive: • ~ 500 EUR / ch • Still Large data size: • ~ 2 MB/Spill (10 samples/signal) Jean-Sébastien Graulich

  7. Charge w/o ADC • Solution 2 (Thanks to Emilio Radicioni) • TDCs exist • CAEN V767 and/or V1190 (128 ch/module !) • < 50 EUR/ch • 1 datum /ch -> ~ 350 kB/Spill (w/o zero suppression) • Zero suppression comes for free ! • Stretcher possible ? Resolution ? Th Stretcher TDC With ToT Tot ~ Q Time over Threshold ~ Q Jean-Sébastien Graulich

  8. Conclusion • Conventional ADC should be excluded • Flash ADC can be used but they are expensive • Maybe we can be smart and use only TDC • Expertise in electronics from Sofia is very welcome/valuable • I am only proposing ideas • Don’t expect me to build the hardware Jean-Sébastien Graulich

More Related