1. e.g. an IceCube Surfave Veto Array TAXI. Transportable Array for eXtremely large area Instrumentation studies Timo Karg, Rolf Nahnhauer DESY IceCube Collaboration Meeting 3 March 2014 in Banff

2. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 2 see also our presentation at the Munich meeting: https://events.icecube.wisc.edu/getFile.py/access?contribId=88&se ssionId=33&resId=0&materialId=slides&confId=51 https://events.icecube.wisc.edu/getFile.py/access?contribId=88&se ssionId=33&resId=0&materialId=slides&confId=51 TAXI Concept

3. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 3 R&D station SensorsCommunication Power SourceReference Detector

4. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 4 Idea: Use a simple reference air shower detector for trigger and coarse reconstruction S i : reference air shower detectors (plastic scintillator) 10 m First Step: Single Station sensor power DAQ S2S2 S1S1 S3S3 Sensor R&D

5. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 5 100 m Second Step: Cluster (4 Stations) power DAQ Array R&D

6. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 6 Requirements > Highly modular system that allows easy interchange of components  R&D environment for different system components with well defined interfaces > Easy transport and setup: site studies for future projects  long term background measurement and monitoring  signal propagation studies (signal speed, attenuation, refraction, …) > Operation at isolated sites  low power, self-sustained power supply  environmental range from Antarctica to hot climate > Scalability

7. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 7 Status: Station 1 Operational test sensor, here: SALLA antenna (courtesy of Tunka-Rex) DESY Zeuthen, Mechanical Workshop reference detectors: 1 m 2 plastic scintillator, segmented Power: cabled Comms.: cabled (Ethernet) In Preparation: Replace off-the-shelf DAQ with low-power, single-board design

8. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 8 In Preparation: Reference Detector Readout v2 AERA-trigger optional, switchable ring sampler (waveforms for calibration, debugging) goal: power consumption < 10 W (w/o ADC) rel. timing, time-over-threshold in FPGA (0.5 ns accuracy) abs. time: GPS (15 ns accuracy; best case)

9. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 9 Test-Sensor Readout > Developed at KIT (IPE, IKP) for the Auger Engineering Radio Array (AERA) > Four digitizers (180 MHz, 12 bit; can be interlaced to 2 × 360 MHz) > Deep ring buffer (7 seconds for 2 channels @ 180 MHz) > Powerful FPGA for real-time signal processing > External trigger from scintillation detector > Power: < 10 W (including LNAs for radio antenna) Block diagram: A. Schmidt, PhD Thesis, KIT (2012)

10. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 10 TAXI & IceCube Surface Veto Array

11. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 11 Scenario 1: (In-Situ) Characterization of Detection Units > Use new Detection Units (IceBag, …) as test sensor (would replace radio antenna; minor modifications to analog front-end required) > Detailed study of the air-shower response of Detection Units  In the North and in-situ! > Reference detectors allow triggering and reconstruction of air showers  Estimate of particle density and arrival time at Detection Unit  Full Detection Unit response (waveforms) available via AERA board

12. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 12 Scenario 2: TAXI Electronics As Basis for Veto > TAXI is modular! > AERA Board (test-sensor readout) can be removed > Veto Detection Units replace reference detectors > Read out leading edge time and time-over-threshold  optionally full waveforms via DRS4 at the expense of higher power requirements > TAXI interface allows us to use different  power supplies  communication modules  synchronization protocols (not yet)

13. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 13 Some Thoughts About the Surface Veto > For “conventional” array: ½ to ⅔ of the cost are cables (M. DuVernois, Munich Coll. Mtg.) Can we reduce / simplify the cabling? > Power  Tricky at South Pole, some experience from ARA with wind turbines > Communications  Assume ~kHz trigger rates for each Detection Unit; only transmit timestamps  Transmit few kByte / second from each Detection Unit  Receive and buffer few MByte / second at ICL  Wireless comms. seems possible > Synchronization  Assume veto window of 1 µs  GPS receiver at each station (few 10 ns accuracy) feasible > In case fibers are run: White Rabbit + Gbit Ethernet is an option Jan, ICRC 2013

14. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 14 Summary and Outlook > TAXI is a modular cluster for research & development on different aspects of arrays, e.g. an IceCube Surface Veto Array  Single station with external air shower trigger: test, characterization, and calibration of sensors / detector units  Four station cluster: development and test of clock synchronization, trigger, communication, and power distribution  easily transportable: in-situ tests and exploration of prospective sites > One prototype station constructed and successfully taking data > Timeline  Mid 2014: low-power, single-board readout available  End 2014: complete four station array at Zeuthen site

15. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 15 Backup Slides

16. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 16 Station 1 DAQ Power supply VME readout: Raspberry Pi AERA board Cable delay for QDC VME DAQ for Scintillators (QDC + TDC) Power control via Ethernet Temperature + humidity mon. Trigger board

17. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 17 Scintillation Detector > Input: ± 12 V > Output: differential, analog PMT signal (8 channels) combined to 4 segments of 50 × 50 cm for readout optical fibers each tile read out by 2 sets of fibers Hamamatsu R 5900-3-M4 2 × 2 multi-anode PMT 1 m 2 tiled plastic scintillator 16 tiles, 25 × 25 cm each

18. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 18 Reconstructed Directions Azimuth Elevation vertical horizontal More horizontal events missing Direction of air shower reconstructed from arrival time differences Shadowing effect by experimental hall (35 days of data)

19. T. Karg, R. Nahnhauer | TAXI | 3 March 2014 | Page 19 View in the Direction of 270°