1. High-precision timing discussion 1 David Berge University of Amsterdam & Nikhef GRAPPA Gravitation AstroParticle Physics Amsterdam Research Priority Area o Introduction o CTA

2. Precision timing over large distances White Rabbit: http://www.ohwr.org/proje cts/white-rabbit http://www.ohwr.org/proje cts/white-rabbit Open hardware project CERN, GSI, Nikhef, and others Based on standard Ethernet protocol – Currently implemented for 1 Gbit/s 2

3. Precision timing over large distances White Rabbit: http://www.ohwr.org/proje cts/white-rabbit http://www.ohwr.org/proje cts/white-rabbit Delivers: – Ethernet timing network up to 2000 nodes, up to 10 km apart – Precision time sync: accuracy 1ns, precision (==clock jitter) 20ps – Deterministic message passing (controls, monitoring, etc) – Built-in phase monitoring and compensation 3

4. Precision timing over large distances 4 Taken from J.Serrano, CERN Built-in phase calibration (automatic temperature adjustment)

5. White Rabbit applications CERN GSI / FAIR KM3Net TUNCA / HiSCORE (deployed last year) Tests ongoing for CTA, LHASSO 5

6. Goal of today Come together and discuss our needs See if there are commonalities Enable knowledge exchange – E.g. equipment used (rubidium frequency reference) For CTA-NL – porting WR to 10 Gbit/s is main future development need – engineering resources are not available (except maybe for Groningen) – my goal is to see whether a dedicated Dutch effort (particle, astroparticle physics, astronomy) provides a good case to apply for money (but don’t know where yet) 6

7. Next-generation gamma-ray observatory

8. Key design goals:  10-fold increased sensitivity at TeV energies  10-fold increased effective energy coverage (10 GeV – 300 TeV)  Larger field of view for surveys  Improved angular resolution  Full sky coverage: an array in each hemisphere 27 countries, ~1100 persons, ~2e8 Euro investment, construction planned 2015-2020

9. ~ 120 m  -ray enters the atmosphere Electromagnetic cascade 10 nanosecond snapshot 0.1 km 2 “light pool”, a few photons per m 2. Cameras: O(1000 pixels), O(100 cm 2 ), read out at O(1 kHz)

10. Data and trigger rates Night-sky background (stars, zodiacal light): 50 MHz per pixel Air-shower trigger: look for blobs (3- 5 pixels) in each camera Events then dominated by proton air-showers and individual muons (1e-4 are gammas) Coincidences (at least 2 cameras) before storing events (1e-2 are gammas) 10

11. Data and trigger rates Depending on telescope type, 200 MB/s to 5 GB/s At 10% duty cycle, get to a few PB per year 11

12. Current CTA instrumentation projects NOVA-4 instrumentation grant, 1.2 M€ (0.2 M€ contingency)

13. NOVA Work Packages WP1: contributions to the CHEC camera project for the dual- mirror SSTs (Amsterdam) WP2: development of new photo-sensors for CHEC (Nijmegen) WP3: SST pointing reconstruction system (Amsterdam & ASTRON) 13

14.  -rays at UvA – CTA timing David Berge14 Measure 10ns light pulses to better than 10% Sync clocks to better than 1ns Collaboration with Nikhef

15. SST camera electronics work David Berge - CTA Instrumentation White Rabbit: need <1ns clock sync between cameras, spaced up to 7km apart 15

16. Camera data and timing interface card Seven Solutions – One of the partner companies of the White Rabbit Open Hardware consortium We needed data switch plus clock generation and timestamping – Seven Solutions switch board does just this – White Rabbit switch functionality not used for now Have to be able to deal with 1.3 – 2.6 Gbit/s per camera Long term: same board / implementation between KM3Net and CTA? 16

17. Camera data and timing interface card 17

18. Camera data and timing interface card 18

19. Timing meeting room H320 Cell David Berge: 06 46812049 Ad van den Berg P. Lemmens Arpad Szomoru Jeroen Koelemeij Peter Maat Paul Boven 19