T h e S t a t u s o f T e l e s c o p e A r r - PowerPoint PPT Presentation

S c i e n t i f i c A c t i v i t i e s o f I C R R ” S c i e n t i f i c A c t i v i t i e s o f I C R R ” “ “ - - - O O b s e r v a t i o n o f U l t r a - h i g h E n e r g y C o s m i c R a y s - - - - - - b s e r v a t i o n o f U l t r a - h i g h E n e r g y C o s m i c R a y s - - - T h e S t a t u s o f T e l e s c o p e A r r a y T h e S t a t u s o f T e l e s c o p e A r r a y O c t . 1 9 t h , 2 0 0 6 @ K a s h i w a , J a p a n O c t . 1 9 t h , 2 0 0 6 @ K a s h i w a , J a p a n M . F u k u s h i m a M . F u k u s h i m a

Telescope Array (TA) Originally planned as a large array of fluorescence telescopes to identify the origin of super-GZK (E > 10 20 eV) cosmic rays (ICRR review in 2000). HiRes monocular spectrum suggested existence of GZK cutoff (27 th ICRC @ Hamburg in 2001). Physics? Method? Statistics? Critical look at systematics of SD (AGASA) and FD (HiRes) measurements became imperative. Phase-1 TA financed in 2003 as SD / FD hybrid detector.

Mechanism of GZK Cutoff Mechanism of GZK Cutoff ν e γ ＋ ＋ μ ν π p γ ＋ E = 1 0 0 e V 2 p n E 0 . 8 x 1 0 0 e V 2 ̃ 0.6 x 10 -27 cm 2 2.725 K Cross Section (mb) Cross Section (mb) Cross Section (mb) 0.1 0.1 0.1 γ + p →Δ（ γ + p →Δ（ γ + p →Δ（ 1232 ） 1232 ） 1232 ） 411 ph / cm 3 → π o p or π + n → π o p or π + n → π o p or π + n 0.01 0.01 0.01 Gamma Beam Energy (GeV) Gamma Beam Energy (GeV) Gamma Beam Energy (GeV) The super- -GZK Cosmic Rays must call for a New Physics. GZK Cosmic Rays must call for a New Physics. The super

Energy Spectra by AGASA and HiRes (mono) Fluorescence Telescope Ground Array (plastic scintillator) AGASA HiRes

A G A S A : s t o p p e d i n J a n , 2 0 0 4 A u g e r : 1 s t r e s u l t i n A u g . 2 0 0 5 H i R e s : s t o p p e d i n A p r . 2 0 0 6 T A : w i l l s t a r t D A Q i n A p r i l 2 0 0 7 A u g e r - S o u t h : w i l l b e c o m p l e t e d i n 2 0 0 7

AGASA SHINOZAKI @WeiHai, 2006

HiRes New “ fully efficient ” stereo Most recent Mono spectrum (with cloud cuts) Spectrum - no cloud cuts Monocular Spectra SOKOLSKY @WeiHai, 2006

AUGER ZAVRTANIK @WeiHai, 2006

AUGER ZAVRTANIK @WeiHai, 2006

N o c o n c l u s i o n r e a c h e d o n G Z K . E n e r g y S c a l e i s i n q u e s t i o n . B u t i t m a y n o t b e t h e o n l y c a u s e o f D i s c r e p a n c i e s . E v e n a f t e r e n e r g y r e s c a l i n g , # o f e v e n t s w i t h E > 1 0 e Vd i f f e r s a m o n g e x p e r i m e n t s . 2 0

A G A S A : s t o p p e d i n J a n , 2 0 0 4 A u g e r : 1 s t r e s u l t i n A u g . 2 0 0 5 H i R e s : s t o p p e d i n A p r . 2 0 0 6 p h - 1 T A : w i l l s t a r t D A Q i n A p r i l 2 0 0 7 A u g e r - S o u t h : w i l l b e c o m p l e t e d i n 2 0 0 7

Millard County in Utah / USA Phase- -1 TA 1 TA Phase 576 Counters Comm. Tower AGASA x 9 CLF TALE TALE 3 x Fluorescence Stations Low Energy Extension AGASA x 4

Plastic Scintillator 3 m 2 , 12 mm t WLSF readout, 2 layers overlaid 1 MI P phot o-elect ron distribut ion 24 pe

• 50 MHz, 12 bit FADC • GPS time stamp (~20ns) • Wireless LAN modem • Solar panel + charge controller • Battery • Slow control

m u o n s p e c t r u m Spectrum and Rate for Cosmic Muon t r i g g e r Integrated over 12 time bins (240ns) Wave form recorded 628 Hz at 1/3 μ U p p e r l a y e r locally at each counter T i m i n g s e n t t o 42 Hz at 3 μ c o m m . t o w e r f o r C o i n c i d e n c e T r i g g e r ~ 1000 Hz. Triggered by lower layer at 1/3 μ level

Why Plastic Scintillator ? � Conserve AGASA energy scale and check � Sample electromagnetic shower (~90% of Eprimary) >>> less dependent on may vary over GZK energy • primary composition • hadronic interaction @EHE Why Two Layers ? � trigger and calibration by muon � wider dynamic range (PMT Gain H/L) linear upto 60 / 360 MIPs in 20 ns S(600) for 3 x 10 20 eV

AUGER Particle density at 540m from shower core vs X - Xmax Iron/QGSJET � Iron/SIBYLL 0 o 25 o 36 o Proton/QGSJET 45 o Proton/SIBYLL e � 53 o Z E N I T H A N G L E 60 o 66 o � � ARISAKA GAP 2004-037

Expected Signals from e, γ , μ 2.0 mm t Al b y G E A N T f o r 1 0 e V p r o t o n s h o w e r 1 6 1.2 mm t Fe @ 6 0 0 g / c m a n d 1 k m a w a y f r o m c o r e 2 1.0 mm t Fe 1.2 mm t Fe # of particles in lower scintillator 10 mm t Scint. # of particles in upper scintillator

○ 80% of ○ 80% of SDs SDs & 3 towers on federal land. & 3 towers on federal land. ○ Took 2.5 years for getting permission from BLM office. ○ Took 2.5 years for getting permission from BLM office. Surveys of endangered animals and plants, cultural resources Surveys of endangered animals and plants, cultural resources and historical sites, and numerous other administrative works orks and historical sites, and numerous other administrative w . done by U of Utah colleagues . done by U of Utah colleagues th + 16 ○ First comm. tower built on Sept.15 ○ th First comm. tower built on Sept.15 th + 16 th ○ First 50 counters will be deployed today (Sept 19). ○ First 50 counters will be deployed today (Sept 19). ○ 516 counters will be in the field by next February. ○ 516 counters will be in the field by next February. ● 合計５ 合計５ １ ６ 台を、 ２ ０ ０ ７ 年２ 月までに設置の予定 ● １ ６ 台を、 ２ ０ ０ ７ 年２ 月までに設置の予定

SDs waiting for Deployment near Delta Cosmic Ray Center

TEST DEPLOYMENT in Dec. 2004 From Delta to staging area (~30km) 18 SDs at the staging area 18 SDs deployed in 3 hours

FLUORESCENCE ELESCOPE • Fixed telescope with spherical mirror • One telescope with 18 0 x 15 0 FoV seen by mosaic PMT camera • 6 x 2 telescopes / station • Field of View 3 0 -33 0 for elevation 108 0 for azimuth

TELESCOPE CAMERA • 16 x 16 PMT array • BG3 glass filter (UV transparent) • Pre-amplifier (x 50) 1. 3 PMTs: absolutely calibrated by standard UV light source (self develop.) & PMT gain monitored by YAP + 241 Am. 2. All 256 PMTs: relatively adjusted in situ by diffused light ( Xenon flasher ) 3. XY-mapping by UV-LED scanner

TELESCOPE ELECTRONICS FADC Track Trig. PC LV HV PS 1 camera

One of the first events of TA: 2005/07/12, 2:52 am, Utah. 200 ns / step. top / bottom & left / right of camera view reversed.

Spherical Mirror (3.3m � ） , 1 0 pixel PMT � Conserve HiRes optics (30% more light than HiRes) � Simple in Optics & Mechanics � “ Sandwich ” configuration for stereo meas.. • less than 20 km to the nearest FD station • always tagged by the SD -HV, DC coupled, 40MHz,12-bit sampling � No wave form distortion � Direct night sky BG measurement � “ FD as a lidar ” � ~ms baseline update � 5 contiguous PMTs for “ track ” trigger

1 st FD station: 8 / 12 telescopes completed • • 2 nd station: to be ready by March, 2007 • 3 rd station: transfer of HiRes. Ready by June, 2007 .

FD is a Total Absorption Calorimetry for absolute energy measurement 2 . A t m o s p h e r i c C o r r . 1 . F l u o r e s . E f f . loss of photons � E # of photons Air Fluorescence Spectrum 3 . T e l e s c o p e C a l i b . # of ptotons ADC ch