T. Fujii1,2, P. Privitera1, J. Jiang1, A. Matalon1, P. Motloch1, M. Casolino3, Y. Takizawa3, M. Bertaina4, J. Matthews5,

K. Yamazaki6, B. Dawson7, M. Malacari71KICP University of Chicago, 2ICRR University of Tokyo, 3RIKEN, 4University of

Torino, 5University of Utah, 6Osaka City University, 7University of Adelaide 2014/Sep/20, JPS Meeting

Segmented mirror telescope Variable angles of elevation – steps.

construction is still in development

15 deg 45 deg

Joint Laboratory of Optics Olomouc – March 2014 7

次世代極高エネルギー宇宙線観測のための新型大気蛍光望遠鏡の開発

Segmented mirror telescope Variable angles of elevation – steps.

construction is still in development

15 deg 45 deg

Joint Laboratory of Optics Olomouc – March 2014 7

2

Fine pixelated camera (Auger, TA)

Low cost single pixel telescope (FAST)

✦ Target : > 1019.5 eV, UHE nuclei and neutral particles

✦ 10×Auger, 40×TA on ground

Fluorescence detector Array of Single-Pixel Telescopes (FAST)

Reference design1 m2 aperture, 15°×15° per PMT

Too expensive to cover a large area

Window of Opportunity at TA-EUSO

3

EUSO prototype�

Telescope Array, Utah, USA Black Rock Mesa site

✦ Temporally borrow the EUSO optics in the TA site.

✦ Two Fresnel lenses (+ 1 UV acrylic plate in front for protection)

✦ 1 m2 aperture, 14°×14° FOV ≒ FAST reference design.

✦ Installation in February 2014, test measurements in April and June 2014.

✦ Collaboration between Pierre Auger, Telescope Array and JEM-EUSO.

M. Casolino (RIKEN), M. Bertaina, M. Marengo, F.

Borotto, B. Giraudo(INFN-Torino)

JEM-EUSO optics

Camera of FAST

4

PMT 8 inch R5912-03E7694-01(AC coupling)MUG6 UV band pass filter

YAP (YAIO3: Ce) scintillator with 241Am (50 Hz, ~1000 p.e.) to monitor stability.

Np.

e. /

100

ns

YAPSignal

Anode & dynodeSignal

DAQ System

5

TAFD external trigger, 3~5 Hz

AmplifiersR979 CAEN

Signal×10

Camera of FAST

High Voltage power supply, N1419 CAEN

Portable VMEElectronics- Struck FADC 50 MHz sampling, SIS3350 - GPS board, HytecGPS2092

15 MHz low pass filter

All modules are remotely controlled though wireless network.

Phillips scientificSignal×50

Installation in February 2014

6

Start observation!!

1 2 3

4 5 6

7 8 9

Operation in Clear Night

7

12.3°C 5.5°C

9 hours data taking

+9.6%

Close

Open

Electronicnoise level

Night skybackground

12 p.e./100 ns

✦ Variance proportional to PMT current. Electronic noise is negligible with regard to night sky background.

Become quieter background

✦ Good gain stability during data taking, consistent with PMT gain temperature dependence of -1.4%/℃

σ2p.

e. /

100

ns

σ2p.

e. /

100

ns

Timing and CLF Signal

8

Average of 223 shots ✦ FAST- TAFD timing resolution,

100 ns. (20.9 µs is the TAFD trigger processing time.)

✦ laser signal ~ 1019.5 eV at 21 km

✦ peak signal ~ 7 p.e. / 100 ns (σp.e. = 12 p.e.) at the limit of detectability

64 CHAPTER 3. TELESCOPE ARRAY EXPERIMENT

Figure 3.28: The CLF system located at the center of TA (left) and the insidepicture of CLF (right).

Additionally, the LIDAR system has been installed at CLF location inSeptember 2010. When shooting the laser, the back-scattered photons aredetected at the ground. Thus, the telescope system same as LIDAR was set upto measure back scattered photons from CLF laser. Fig. 3.29 shows the imageof LIDAR system and the typical result of VAOD measured by both LIDARsystems located at BRM and CLF. While the LIDAR at BRM operates in thetime to start and finish every observation, CLF is shooting the laser every 30minutes. Since these results are consistent and complementary, we can use theatmospheric parameter with better time resolution in near future.

Figure 3.29: The image of LIDAR system installed at the CLF location (left)and VAOD relationship measured by CLF and LIDAR (right).

Central Laser FacilityVertical UV laser shooting every 30 minutes, 21 km from FAST, 10 Hz, 2.2 mJ, 300 shots

Np.

e. /

100

ns

Time (20 ns / bin)0 500 1000 1500 2000 2500 3000 3500 4000

p.

e.N

0

1

2

3

4

5

6

7

Preliminary CLF Simulation

9

Raytracing

-7°

0°

+7°

+14°

-14°

Laser length: 20 usec

Distance : L

1bin = 6.0e-3 km

t = 0 bin = 0

10,000 photons in the a bin of laser length

8 inch ≈ ±7° FOV

Data

Simulation

Np.

e. /

100

nsN

p.e. /

100

ns

Y. Takizawa (RIKEN)

Directional sensitivity

Efficiency

Portable Laser Signal

10

Single Laser shot

FAST

FAST FOV

HitCloud

Np.

e. /

100

ns

TAFD

Np.

e. /

100

ns

✦ Vertical UV laser with same energy of CLF (~1019.5 eV) at 6 km from FAST.

✦ Peak signal ~ 300 p.e. / 100 ns. All shots are significantly detected.

✦ Expected signal TAFD/FAST: (7 m2 aperture × 0.7 shadow × 0.9 mirror) / (1 m2 aperture × 0.43 optics efficiency) ~ 10

Shower Signal Search

11

FAST

TAFD

Np.

e. /

100

ns

FAST FOV

✦ We searched for FAST signals in coincidence with TAFD showers in the FAST field of view.

✦ Data set: April and June observation, 19 days, 83 hours.

✦ 16 candidates found.

✦ Low energy showers as expected.

1018.0 eV

Distance vs Energy (from TAFD) for candidates

12

(E (eV))10

log17 17.5 18 18.5 19 19.5 20

Rp

[km

]

1

10

210

Detectable

April+June RUN

FAST FOV

1018.1 eVAlmost! 1019.1 eV

Np.

e. /

100

ns

Rp (Impact parameter)Shower axis

Preliminary

]2 [g/cmmaxReconstructed X400 500 600 700 800 900 1000 1100 1200 1300 1400

Ent

ries

0

100

200

300

400

500

600

eV19.510

f = 1.17

Proton EPOS

Iron EPOS

Simulation Study

13

Segmented mirror telescope Variable angles of elevation – steps.

construction is still in development

15 deg 45 deg

Joint Laboratory of Optics Olomouc – March 2014 7

✦ Reconstruction efficiency

✦ FAST with 20 km spacing

✦ 100% efficiency at 1019.5 eV

✦ With smearing SD accuracy of geometry, Xmax resolution of FAST is 30 g/cm2 at 1019.5 eV.

✦ Under implementing a reconstruction by only FAST.

logE Proton Iron

18.5 0.65 0.56

19.0 0.88 0.89

19.5 0.99 1.00

Including Xmax

resolution

✦ 4 PMTs Telescope

ProtonIron

Summary and Future Plans✦ Promising results from the first field test of FAST concept:

✦ very stable and simple operation

✦ robust behavior under night sky background (gain stability, a single bright star does not matter when integrating over the large FAST FOV)

✦ laser shots and shower candidates detected

✦ sensitivity is consistent with simulated expectation

✦ Very successful example of Auger-TA-EUSO collaboration.

✦ Several improvements possible, e.g. high Q.E. PMT, narrow UV pass filter, mirror design, reconstruction method, etc.

✦ Next step: full 30°×30° prototype. 14

Conclusions and Outlook

17

• This design was not optimized for FAST: e.g. very small spot size, small eff. Plateau, light attenuation in three lenses, expensive optics.

• Several improvements possible, e.g. lower energy threshold with high QE PMTs, mirror design, etc. (a factor 4 gain in sensitivity easily feasible)

• Next step: full 300 x 300 prototype in Argentina

Olomuc

Segmented mirror telescope Variable angles of elevation – steps.

construction is still in development

15 deg 45 deg

Joint Laboratory of Optics Olomouc – March 2014 7