CRYSBEAM crystal extraction and detectors

Gianluca Cavoto (INFN Roma) CERN Mar 16th 2015

G.Cavoto

Outline Efficient crystal extraction of a multi-TeV hadron

beam Demonstrate it is useful for fixed target experiments

The INFN CRYSBEAM(*) project

Develop a suitable crystal Detectors for extracted beam monitoring An application: Cosmic ray physics with the

extracted beam(*) CRYSBEAM is funded by a ERC Consolidator Grant GA 615089 (FP7 IDEAS action) with a 2M euro budget for the period May 2014- May 2019

INFN is the Host InstitutionWebsite : http://crysbeam.roma1.infn.it/

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The CRYSBEAM challenges: the crystal for extraction

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Critical Radius for channeling Given a deflection angle Φ [~1 mrad]

Φ = L/Rwhere R is crystal curvature radius and L is the crystal length

Effective potentialin presenceof centrifugal force(bending)

Critical radiusto have an efficientchanneling

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Channeling efficiency versus Rc

~1 mrad deflection requires ~12cm long Si crystal (or 7 cm long Ge crystal)

Much longer than what UA9 tested and used so far

High efficiency zoneR > 10 Rc

E. Bagli et al., Eur. Phys. J. C (2014) 74:2740

Si (110):Rc = 12m at pb = 7 TeV

Ge (110):Rc = 7m at pb = 7 TeV

Experiment (H8 and SPS): Si bent crystal (L = 0.2cm) (1 1 0) plane 400 GeV/c protons

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New bending technology For a very long crystal (~10

cm), a new holder need be designed!

Large primary bending to generate anti-clastic bending

Assisted curvaturewith tensile layer deposition or ion implantation

Working on a intermediate length crystals

beam

UA9 LHC crystalAnticlasticcurvature

A.Mazzolari,V.Guidi

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Beam monitoring

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Radiator with position sensitivity Ultra-fast high power laser writes waveguides!

Use to build quantum-optics device “write” several

optical waveguide to trap Cherenkov light (as a bundle of fibers)

Connect each waveguide to a separate light sensor (SiPM, APD,…)

Position information given by which channel fires

Instrumented beam silica thin window

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New concept: cutting holes

Instead of writing the core of the planar waveguide in the glass, we remove the

glass to create a low index cladding

Advantages:• Very high index change Critical

angle 43° (47° is totally reflected) @455nm

• No Cherenkov radiation is generated in the cladding high SNR

R.Osellame PoliMI-CNR

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Irradiation and chemical etchingIrradiation: 1 kHz, 150 fs

5 µJ @ 800 nm

15 µm/s 0.3 NA 200 µm

buriedEtching: 20 % HF in water

Ultrasonic bath

3 h time

HF acid bath

Waveguide

Pre-etching irradiation

Fused Silica Glass

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Sample with waveguide separation

Front image Side image

Scale bar 100µmNo glassglass

Planar waveguide

90µm:70µm

180µm:80µm

White light transmission

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Test with laser lightCW laser light @473 nm entering from the side face at an

incident angle α

Angle of incidence a~45° corresponding to an internal angle with respect to z of ~61°.

α

z

To be tested with 500 MeV electrons at BTF in Frascati

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Waveguide tapering Matching SiPM size

5 mm straight

13 mm curved

0, 5 mm1,2mm1,2mm1,2mm1,2mm

1,2mm

3mm

Glass thickness 2mm

0, 5 mm

Particle beam Linear

array ofSiPM detectors

Single SiPM

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Hadronic showers and Cosmic rays

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Ultra High Energy Cosmic Rays

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Hadronic interaction in air showers

Accelerator based experiments to unravel this

(LHC-f, NA61 at CERN,…)

G.M

itsuk

a (L

HCf c

oll)

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CR Mass composition

Shower maximum position Cross sectionPierre Auger Observatory

Data interpretation depends on MC used to described the shower

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Muon in cosmic air-showers

More muons in air-shower data than expected

•Can be a problem in interaction physics in air-shower model ?•Is a muon counting experiment after a beam dump interesting (or enough) tohelp solving this ?•Do we need to study charm content of a shower ? Access to parton with momentum fraction x→1 in the target.•Study production of charm from light nuclei directly?

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Showers of Cosmic Rays in a lab Sub-showers of UHECR air-shower can be

reproduced in lab: compare with MC (CORSIKA) Following shower evolution as in air-shower experiment!

R.Ulrich

Hadron beam of 10 GeV – 10 TeV (both SPS and LHC) Different targets (carbon, water, liq. nitrogen)

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Can be tested on SPS North Area were proton and pion beam are currently available (up to 400 GeV energy)

Eventually moved to LHC (crystal) extracted line

A smart absorber experiment Dump the extracted beam onto a light

element absorber. Possibly change the absorber Count the number of particles crossing thin active

layers

150 cm

50 cm

10 cm

0.5 cm

20

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Small TPC for track imaging

The anode is a quad medipix without silicon sensor:

The active area is 9 cm2

The particle track is analysed with 512 pixel in length of 3 cm

Gas flux

Triple GEM

Kapton windowParticles to be analysed

Length analysedF.Murtas

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GEMPix detector Building a new

version for CRYSBEAM

larger drift region totally sealed

(can be immersed

in a water tank to measure p-O interactions)Particles

from shower

To be tested at BTF with internal graphite (HOPG) target.

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Example of track imaging

F.Murtas – CERF H823/25

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Plans

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CRYSBEAM objectives for 2015 Test LONG crystal bending strategy

Use extreme bending to produce anti-clastic bending on 4 inch wafer

Test a 30mm long crystal in NA Feasibility of silica micromachining for

Cherenkov light collection Test at LNF BTF in Apr/Oct

Test new Cherenkov light trasmission from vacuum to outside (see next talk)

Design a smart absorber Test TPC – GEMpix with internal target (BTF/H8) Design and build large and sealed TPC

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Additional back-up slides

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Germanium technology is mature alternative

Plannar channeling efficiency

Vert

ical

Defl

ecti

on [

mrad

]

SPS-H8-CERN 400 GeV Proton

De Salvador et al. JAP (2013)

Horizontal Deflection [mrad]

First axial channeling in Ge

De Salvador et al. APL (2011)

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Silicon strip manufacturing

a) Starting material: (110) silicon wafer

b) LPCVD deposition of silicon nitride thin layer

c) Silicon nitride patterning (photolithography)

d) Etching of Si in KOH solution, silicon nitride acts as masking layer

e) Silicon strips release

f) Removal of silicon nitride

Established fabrication technique

Revisitation needed!

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Piezo-goniometer installed on LHC Designed at CERN EN-STI group, realized by

CINEL A.Masi

New version under studyPiezo-electric material with higher Curie point (>200 deg) under investigation

Movable beam pipe section

Stepping motor (linear movement)

RF contacts

On the beam pipe a copper and NEG coating could be applied

Linear Stroke: 60 mmLinear resolution: 5 um Total angular range : ±10 mrad Angle resolution: 0.1 µrad Angle accuracy: ±1 urad

Operational position

Movable beam pipe section

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Crystal resistance to irradiation IHEP U-70 (Biryukov et al, NIMB 234, 23-30)

70 GeV protons, 50 ms spills of 1014 protons every 9.6 s,several minutes irradiationchanneling efficiency unchanged.

SPS North Area - NA48 (Biino et al, CERN-SL-96-30-EA)

450 GeV protons, 2.4 s spill of 5 x 1012 protons every 14.4 s,one year irradiation, 2.4 x 1020 protons/cm2 in total,channeling efficiency reduced by 30%.

HRMT16-UA9CRY (HiRadMat facility, November 2012):

440 GeV protons, up to 288 bunches in 7.2 μs, 1.1 x 1011 protons per bunch (3 x 1013 protons in total) ➔ comparable to asynchronous beam dump in LHCno damage to the crystal after accurate visual inspectionmore tests planned to assess possible crystal lattice damageaccurate FLUKA simulation of energy deposition and residual dose

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More on CR physics

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Development of a hadronic shower

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Conceptual experiments with absorber

Segmented absorberActive layers (pixelated?) to measure shower properties

Extracted beam

Extracted beam

target

Q: are shower properties sensitive to cross section on absorber material? (test with FLUKA and SYBILL)

“single-arm” detector

Target material can bechanged.Measure (in a narrow solid angle) exclusive cross-section(anti proton, B, C,..)Detector can be movedat different angles

1

2

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Conceptual experiments (2)

Thin absorber3

“diffracted particle” Dispersive regionof the accelerator:Detected diffracted particles

Use the accelerator as a spectrometer to measure the momentum of diffractive particlesWith two stations, measure angle and momentumDirect measurement of diffractive cross section on absorber materials

Incoming flux detector