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

Experimental Setup of h H8 RD22 E i the H8-RD22 Experiment

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 mm3 and 0.5 × 70 × 3 mm3 beam

Anticlastic bending

• 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 d d th h i f

• ρ depends on the choice of

crystallographic plane and on the angle

• f n111 respect to the crystal face

Crystal plate sizes: ~ 1 × 30 × 55 mm3

Quasi-mosaic bending ding

critical angle for 400 GeV/c θ 10 d

O.I.Sumbaev (1957)

nticlastic bend

R

protons: θc ≈ 10 μrad

An Main bending

R

H8-RD22 apparatus pp

S1 S3 GC S5

Goniometer with crystal holders vacuum vacuum

p S2 H S4 S6

B5 B6 Si microstrips (AGILE) Si microstrips (AMS)

S

( ) 70 m

• Scintillators (S1-S6)
• Scintillating Hodoscope (H)
• Bending Magnets (B5-B6)
• Gas Chamber (GC)

Proton beam

• CERN SPS H8 beamline
• CERN SPS H8 beamline
• Primary 400 GeV/c proton

beam T i l b i t it t T4

• Typical beam intensity at T4

target: ~20 × 1011 ppp

• The experiment required

d d

4

reduced rates ~5 × 104 ppp Measurement results Measurement results

• ~8 μrad divergence

2 b t i t

• ~2 mm beam spot size at

crystal location

μrad

High precision goniometer g p g

Silicon detector Crystals Scintillator Goniometer Goniometer Granite Block Granite Block

Goniometer (1) ( )

two translational stages two translational stages

2 μm bidirectional

repeatability

full range of 102 mm

(upper stage) and 52 mm (lower stage) ( g )

• ne rotational stage

360° rotation 1.5 μrad accuracy

1 d t bilit

1 μrad repeatability

Goniometer (2)

Rotation axis of the goniometer Rotation axis of the goniometer Rotation axis of the goniometer Proton beam Rotation axis of the goniometer Proton beam Rotation axis of the goniometer Proton beam

( )

Crystal holder Crystal holder

• o

ea

• o

ea

• o

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

Goniometer for planar channeling

Goniometer (3) ( )

Interferometric measurements

capability to return to

the defi ed

• itio

the defined position within 1.5 μrad

± 1 μrad angular

steps

AMS silicon detectors

Silicon thickness: 300

Detector upstream of the crystal (on the granite block):

• 1 double sided silicon microstrip detector:

300 μm

• 1 double-sided silicon microstrip detector:
• Resolution ~ 10 μm in bending direction (X

coordinate)

• Resolution ~ 30 μm in non-bending direction (Y

coordinate) coordinate)

• Active area ~ 7.0 × 2.8 cm2

Detector downstream of the crystal (on the granite y ( g block) :

• 1 BABY double-sided microstrip detectors (IRST):
• Resolution better than 10 μm in bending direction
• Resolution better than 20 μm in non-bending
• Resolution better than 20 μm in non bending

direction

• Active area ~ 1.9 × 1.9 cm2

DOWNSTREAM TELESCOPE (at 65 m from crystal location):

• 4 AMS LADDERS:
• Resolution ~ 10 μm in bending direction

Resolution 10 μm in bending direction

• Resolution ~ 30 μm in non-bending direction
• Active area ~ 4 × 7 cm2

AGILE silicon detector

• Single-sided silicon strip detectors
• Built by Agile (INFN/TC-01/006)

y g ( )

• active area 9.5 × 9.5 cm2
• Spatial resolution: ~ 40 µm at normal incidence

(~ 30 µm for tracks at 11°) Sili thi k 410

• Silicon thickness: 410 μm
• 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 l i l d

• 6 X-Y silicon planes interleaved

with 300 µm tungsten planes

Gas chamber and scintillators

Gas Chamber

P ll l l t h b

• Parallel plate chamber
• 0.6 × 12.8 mm2 active area
• filled with Ar 70% + CO2 30%
• 64 strips (pitch equal to 200 μm)
• 64 strips (pitch equal to 200 μm)
• mounted on X-Y table
• able to withstand rates up to 108 ppp

Scintillating detectors

• Finger scintillators: 0.1 × 1 × 10

mm3

• Scintillating hodoscope: 16 strips

with 2 × 4 × 30 mm3 read-out by MAPMT (fast beam monitoring)

• Scintillator plates 100 × 100 × 4

p mm3 used for triggering silicon detectors

Laser pre-alignment p g

• laser beam, parallel to

proton beamline

crystal pentaprism

• 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- alignment was about 0.1 mrad

screen LASER

Angular scan: example g p

Fast identification of channeling position with parallel plate

chamber Fi e te a ula

Fine step angular

scan

Detailed angular

measurement with silicon detectors All d d

All data are stored

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 μrad)

Goniometric system with ~1 μrad precision and the Goniometric system with ~1 μrad 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