1. D. Bertrand, J. De Bruyne, P. De Harenne, L. Etienne, S. Hannaert, G. Van Beek The Arch

2. The Arch 2 The Arch Determination of the cosmic rays zenith angle distribution by timing measurements Demonstration of the principle of a TOF detector Practical for 3 rd (or 4 th ) year students Future: recording of Cherenkov rings with a multi-anode PM

3. The Arch 3

4. The Arch 4 Detector elements Based on scintillator strips of the target tracker module of the OPERA experiment; 7 m bars cut into 13 cm rods (TiO 2 on end faces); Grooves enlarged in order to put 2 wls fibers; Glued horizontally.

5. The Arch 5 Detector elements 8 rows of 40 rods  Ribbon length 517 cm, width 21 cm; 16 wls fibers (604 cm each); Read by Hamamatsu H6780 PM’s (gain: 10 6 ; rise time: 780 ps, transit time spead 230 ps; DC-DC converter)  PM1 & PM2

6. The Arch 6 Detector elements Central module: 21 × 21 × 2 cm 3 plastic scintillator read by 2 face to face PM’s (Hamamatsu R7400) gain ~10 6 @ 850 V rise time: 780 ps transit time spread: 230 ps  PM3 & PM4

7. The Arch 7 Calibration Time/position: 16 blue LED’s (8 on each side of the ribbon) Efficiency: 21 × 21 × 2 cm 3 plastic scintillator read by a Photonis XP3102 PM gain : 5 × 10 5 @ 900 V rise time: 2 ns transit time: 23.8 ns  PM5 moveable in 8 positions along the Arch corresponding to the LED0/LED7 positions

8. The Arch 8 Specific electronic modules TDC CAEN V1290A: 320 MHz clock + DLL with 32 delay elements  98 ps R-C delay lines  very high resolution (25 ps) but needs calibration following an internal design Hits stored in individual buffers for each channel Buffers emptied in a FIFO (32kwds of 32bits) Continuous or trigger induced reading Low threshold discriminator CAEN N417: 8 channels with separate adjustable threshold and width Width range: 15 – 800 ns Threshold range : 1.5 – 250 mV 2 channels/PM (double discrimination)

9. The Arch 9 TDC reading in trigger mode Window offset Match window width Extra search margin Reject margin Match window width < | window offset | ≤ 4095 clock cycles = 102375 ns Match window width + window offset ≤ 40 clock cycles = 1000 ns Memory/FIFO clock cycle : 25 ns

10. The Arch 10 The survey parameters LED positionsOrigin (Top of the Arch)260,3 Meas. Pos.From topRel. Dist.Timing (ns) tw. pair delay LED 08,2-252,164,837,7745,2 LED 173,0-187,364,537,8045,3 LED 2137,5-122,864,737,8545,4 LED 3202,2-58,164,537,9245,6 LED 4266,76,464,637,9045,8 LED 5331,371,064,837,6945,5 LED 6396,1135,864,437,8045,4 LED 7460,5200,2 37,9045,8 LED 8512,6252,364,837,9445,6 LED 9447,8187,577,637,8745,7 LED 10370,2109,951,637,8945,8 LED 11318,658,364,237,9945,8 LED 12254,4-5,965,037,9045,8 LED 13189,4-70,964,637,9445,8 LED 14124,8-135,565,037,9545,8 LED 1559,8-200,5 37,8145,5 Cable delaysns Cable 7441,8 Cable 7541,8 Cable 8150,0 Cable 8250,4 PM17,3 PM27,3 PM32,8 PM42,8 Cable 74+PM344,6 Cable 75+PM444,6 Cable 81+PM157,3 Cable 82+PM257,7 Cable 61 (led t)51,0 Cable 62 (led t)51,0 Cable 55 (PM5)67,2 Rod length (40 rods in 1 row)12,8 Ribbon length516,9 Fiber total length603,5 Extra fiber length (left)43,4 Extra fiber length (right)43,2 Arch diameter 398,3

11. The Arch 11 Width: 100 ns Position calibration (LED’s) LV0 (15 V) LV1 (15 V) LV2 (6.5 V) PM1 PM2 LED Timing unit ~20 Hz Disc LED driver TDC (chan 4) Disc (1.5 mV) Disc (~3 mV) Disc (1.5 mV) Disc (~3mV) PM1 PM2 TDC (chan 0) TDC (chan 1) TDC (trigger) ~200 ns (timing unit) 45 ns (twisted pair) + wls fiber delay 58 ns (PM) + 51 ns (LED timing) + 45 ns (twisted pair) + wls fiber delay LED positionsOrigin (Top of the Arch)260,3 Meas. Pos.From topRel. Dist.Timing (ns) tw. pair delay LED 08,2-252,164,837,7745,2 LED 173,0-187,364,537,8045,3 LED 2137,5-122,864,737,8545,4 LED 3202,2-58,164,537,9245,6 LED 4266,76,464,637,9045,8 LED 5331,371,064,837,6945,5 LED 6396,1135,864,437,8045,4 LED 7460,5200,2 37,9045,8 LED 8512,6252,364,837,9445,6 LED 9447,8187,577,637,8745,7 LED 10370,2109,951,637,8945,8 LED 11318,658,364,237,9945,8 LED 12254,4-5,965,037,9045,8 LED 13189,4-70,964,637,9445,8 LED 14124,8-135,565,037,9545,8 LED 1559,8-200,5 37,8145,5 Cable delaysns Cable 7441,8 Cable 7541,8 Cable 8150,0 Cable 8250,4 PM17,3 PM27,3 PM32,8 PM42,8 Cable 74+PM344,6 Cable 75+PM444,6 Cable 81+PM157,3 Cable 82+PM257,7 Cable 61 (led t)51,0 Cable 62 (led t)51,0 Cable 55 (PM5)67,2

12. The Arch 12 Patch pannels From the ArchTo the Arch On the Arch (side 1)

13. The Arch 13 Position calibration (LED’s) 0 50397400 4 50218275 1 50428700 0 46431100 4 46253000 1 46463050 0 43984525 4 43806025 1 44016500 0 41657325 4 41478250 1 41689050 0 37752050 4 37572775 1 37784800 0 35280825 4 35102500 1 35314550 0 32486850 4 32308750 1 32521350 0 29436825 4 29258600 1 29471300 ●

14. The Arch 14 LED voltage / time distribution width From 0.5 V to 6.5 V

15. The Arch 15 LED voltage / Time delay From 0.5 V to 6.5 V

16. The Arch 16 Gaussian fit (typical witdth: 1.2 ns)

17. The Arch 17 Linear regression LED’s 0-7 v : 16.14±0.06 cm/ns LED’s 1-7v : 16.36±0.06cm/ns LED’s 8-15v : 16.30±0.04 cm/nsv : 16.32±0.03 cm/ns LED’s 1-15  6.13 ns/m

18. The Arch 18 Efficiency PM1/PM2 LV: 15 V Disc: 3 mV PM5 HV: 900V Disc: 30 mV NIM scaler 0.7 0.6

19. The Arch 19 Data acquisition LV0 (15 V) LV1 (15 V) PM1 PM2 Disc (1.5 mV) Disc (20 mV) Disc (1.5 mV) Disc (20mV ) PM3 PM4 TDC (chan 2) TDC (chan 3) TDC (trigger) ~32 ns HV0 (850 V) HV1 (850 V) PM3 PM4 ~32 ns Disc (1.5 mV) Disc (~3 mV) Disc (1.5 mV) Disc (~3mV) PM1 PM2 TDC (chan 0) TDC (chan 1) 20 ns (wls fiber: 3 m × 6.14 ns/m) 57 ns (PM1/2) – 45 ns (PM3/4) + 20 ns (wls fiber: 3 m × 6.14 ns/m) Cable delaysns Cable 7441,8 Cable 7541,8 Cable 8150,0 Cable 8250,4 PM17,3 PM27,3 PM32,8 PM42,8 Cable 74+PM344,6 Cable 75+PM444,6 Cable 81+PM157,3 Cable 82+PM257,7 Cable 61 (led t)51,0 Cable 62 (led t)51,0 Cable 55 (PM5)67,2

20. The Arch 20 LabVIEW acquisition system 100 µ m -2 s -1 x 0.044 m 2 x 0.68 (efficiency) / 2  = 0.48 Hz 1 28264275 2 28245700 0 28275825 3 28245850 0 50571950 2 50546650 1 50578500 3 50545575 0 3554725 2 3524625 1 3550325 3 3525725 0 10165850 2 10144200 1 10173625 3 10144350 1 20795700 2 20772750 0 20809150 3 20772475 0 46348350 2 46330125 1 46372050 3 46331250 ●

21. The Arch 21 Angular distribution

22. The Arch 22 TOF 6.7 ns 12 ns

23. The Arch 23 TOF  Momentum MeV

24. The Arch 24 Momentum angular dependence Left Right

25. The Arch 25 Momentum angular dependence < 20° 20°-40° > 40°