Experimental Setup of the H8-RD22 Experiment h H8 RD22 E i - PowerPoint PPT Presentation

Experimental Setup of the H8-RD22 Experiment h H8 RD22 E i Massimiliano Fiorini (on behalf of the H8-RD22 Collaboration) University of Ferrara – INFN Ferrara University of Ferrara INFN Ferrara CARE HHH 2007 Workshop Crystal Channeling for Large Colliders: Machine and Physics Crystal Channeling for Large Colliders: Machine and Physics Applications CERN – 22 March 2007

Outlook � Experiment in the H8 beam line of the SPS north area area � Silicon crystals � Experimental layout E pe i e a ayou � High precision goniometric system � Proton Beam � Tracking detectors � AMS microstrips detectors � AGILE microstrips detectors AGILE microstrips detectors � Parallel plate chamber � Scintillators and trigger system � Scintillators and trigger system � Crystal alignment and angular scans � Concluding remarks g

Strip silicon crystals p y Crystals sizes: 0.9 × 70 × 3 mm 3 and 0.5 × 70 × 3 mm 3 Anticlastic bending beam Strip Crystals have been fabricated in the Sensors � and Semiconductor Laboratory (U. of Ferrara) y ( ) Mechanical bending exploits anticlastic forces �

Quasy-mosaic silicon crystals Q y y Quasi-Mosaic Crystals fabricated in PNPI (Gatchina, Russia) mechanical bending of the crystal mechanical bending of the crystal � induces bending of the atomic planes (initially flat and normal to large faces of plate) due to anisotropy ρ depends on the choice of d d th h i f � crystallographic plane and on the angle of n 111 respect to the crystal face Quasi-mosaic bending Crystal plate sizes: ~ 1 × 30 × 55 mm 3 ding nticlastic bend O.I.Sumbaev (1957) critical angle for 400 GeV/c R R protons: θ c ≈ 10 μ rad θ 10 d An Main bending

H8-RD22 apparatus pp Goniometer with crystal holders S3 GC S1 S5 vacuum B5 B6 vacuum p H S6 S2 S4 S Si microstrips Si microstrips (AMS) (AGILE) ( ) 70 m Scintillators (S1-S6) Bending Magnets (B5-B6) � � Scintillating Hodoscope (H) Gas Chamber (GC) � �

Proton beam CERN SPS H8 beamline CERN SPS H8 beamline � � Primary 400 GeV/c proton � beam T Typical beam intensity at T4 i l b i t it t T4 � target: ~ 20 × 10 11 ppp The experiment required � reduced rates ~5 × 10 4 ppp 4 d d Measurement results Measurement results ~8 μ rad divergence � ~2 mm beam spot size at 2 b t i t � crystal location μ rad

High precision goniometer g p g Silicon detector Scintillator Crystals Goniometer Goniometer Granite Block Granite Block

Goniometer (1) ( ) � two translational stages � two translational stages � 2 μ m bidirectional repeatability � full range of 102 mm (upper stage) and 52 mm ( (lower stage) g ) � one rotational stage � 360 ° rotation � 1.5 μ rad accuracy � 1 μ rad repeatability 1 d t bilit

Goniometer (2) ( ) Rotation axis of the goniometer Rotation axis of the goniometer Rotation axis of the goniometer Rotation axis of the goniometer Rotation axis of the goniometer Proton beam Proton beam Proton beam o o o o o o ea ea ea Crystal holder Crystal holder Linear stage to put the goniometer on the beam goniometer on the beam Linear stage to put the crystal Linear stage to put the crystal Rotational stage also allows Rotational stage for the holder on rotational axis of the alignement of the crystal the change of the crystal goniometer with the rotation of 180° with the beam (planar channeling) (planar channeling) Goniometer for planar channeling

Goniometer (3) ( ) Interferometric measurements � capability to return to the defi ed the defined position o itio within 1.5 μ rad � ± 1 μ rad angular steps

AMS silicon detectors Detector upstream of the crystal (on the granite Silicon thickness: block): 1 double sided silicon microstrip detector: 1 double-sided silicon microstrip detector: � � 300 300 μ m Resolution ~ 10 μ m in bending direction (X � coordinate) Resolution ~ 30 μ m in non-bending direction (Y � coordinate) coordinate) Active area ~ 7.0 × 2.8 cm 2 � Detector downstream of the crystal (on the granite y ( g block) : 1 BABY double-sided microstrip detectors (IRST): � Resolution better than 10 μ m in bending direction � Resolution better than 20 μ m in non-bending Resolution better than 20 μ m in non bending � � direction Active area ~ 1.9 × 1.9 cm 2 � DOWNSTREAM TELESCOPE (at 65 m from crystal location): 4 AMS LADDERS: � Resolution ~ 10 μ m in bending direction Resolution 10 μ m in bending direction � Resolution ~ 30 μ m in non-bending direction � Active area ~ 4 × 7 cm 2 �

AGILE silicon detector Single-sided silicon strip detectors � Built by Agile (INFN/TC-01/006) y g ( ) � active area 9.5 × 9.5 cm 2 � Spatial resolution: ~ 40 µ m at normal incidence � (~ 30 µ m for tracks at 11°) Sili Silicon thickness: 410 μ m thi k 410 � Upstream detector (before Upstream detector (before � goniometer) 2 silicon detectors at 90° � (corresponds to 1 X-Y plane) ( o espo s o Y p a e) Downstream detector 1 (at 65 m from � crystal location): 4 X Y silicon planes 4 X-Y silicon planes � � Downstream detector 2 (at 65 m from � crystal location): 6 X Y ili 6 X-Y silicon planes interleaved l i l d � with 300 µ m tungsten planes

Gas chamber and scintillators � Gas Chamber Parallel plate chamber P ll l l t h b � 0.6 × 12.8 mm 2 active area � filled with Ar 70% + CO2 30% � 64 strips (pitch equal to 200 μ m) 64 strips (pitch equal to 200 μ m) � � mounted on X-Y table � able to withstand rates up to 10 8 ppp � � Scintillating detectors Finger scintillators: 0.1 × 1 × 10 � mm 3 Scintillating hodoscope: 16 strips � with 2 × 4 × 30 mm 3 read-out by MAPMT (fast beam monitoring) Scintillator plates 100 × 100 × 4 p � mm 3 used for triggering silicon detectors

Laser pre-alignment p g pentaprism laser beam, parallel to � crystal proton beamline measurement of laser beam � deflection (1 mm precision) considering prism-crystal � distance (~1 m) and prism- laser distance (~ 4 m) laser distance (~ 4 m), accuracy of crystal pre- screen alignment was about 0.1 mrad LASER

Angular scan: example g p � Fast identification of channeling position with parallel plate chamber � Fine step angular Fi e te a ula scan � Detailed angular measurement with silicon detectors � All data are stored All d d to disk for offline analysis a a y i

Conclusive remarks � SPS H8 beamline excellent facility for crystal y y channeling and volume reflection studies (very low beam divergence ~8 μ rad) � Goniometric system with ~1 μ rad precision and the � Goniometric system with ~1 μ rad precision and the possibility to host two crystals � Set-up of tracking system with excellent spatial p g y p resolution and minimal material budget � Channeling and Volume Reflection phenomena studied with Strip and Quasi Mosaic Silicon Crystals studied with Strip and Quasi-Mosaic Silicon Crystals (different fabrication techniques) � Measurement of crystals with different crystalline Measu e e t o c ysta s wit di e e t c ysta i e planes orientations: (111) and (110)

SPARES SPARES

Double reflection on Quasi-Mosaic crystal Experimental setup: p p exploited rotational stage � for off-axis alignment of the first crystal (preliminary scan) (preliminary scan) used upper linear stage � for alignment of second crystal many steps for finding � perfect alignment conditions