Crystal technology at PNPI

Crystal technology at PNPICrystal technology at PNPI

Yuri M.IvanovYuri M.Ivanov

Petersburg Nuclear Physics InstitutePetersburg Nuclear Physics Institute

PNPI involved in channeling studies since 1970s:

1979 - prediction of volume capture effect in bent crystals (O.I.Sumbaev)

1982 - observation of volume capture effect with 1GeV protons at PNPI (V.M.Samsonov, O.I.Sumbaev et al.)

1987 - invention of crystal design to focus charged particle beams (A.I.Smirnov)

1989-1992 - spin precession of particles channeled in bent crystal at FNAL

1991-1995 - focusing of proton beam at IHEP

1993-1996 - extraction of proton beam from Tevatron at FNAL

1997-2004 - multi-turn extraction and collimation of proton beam at IHEP

33Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Processing of the crystalsProcessing of the crystalsOrienting with X-rays

Cutting

Grinding and polishing

44Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Double crystal X-ray spectrometerDouble crystal X-ray spectrometer

55Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Scheme of rocking curve measurementScheme of rocking curve measurement

66Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Focusing with bent crystalFocusing with bent crystal

A.I.Smirnov 1987 Experiment PNPI-IHEPA.I.Smirnov 1987 Experiment PNPI-IHEP 1991 1991

F2 = 4r2 – R2

F - focal distance

R - bending radius of the crystal

r - radius of the exit crystal face

77Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Samples of focusing crystals Samples of focusing crystals

88Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Main results with focusing crystalsMain results with focusing crystals

Focusing of 1-5 mm parallel beam into 30-Focusing of 1-5 mm parallel beam into 30-50 micron line at distances 1-10 m50 micron line at distances 1-10 m

Deflection and transformation of divergent Deflection and transformation of divergent beamsbeams

New approach to prepare secondary New approach to prepare secondary particle beamsparticle beams

99Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Deflection and transformation of Deflection and transformation of divergent beams divergent beams

Experiment IHEP-PNPI 1995

1010Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

New approach to formation of secondary

particle beams with focusing crystals

1111Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Multi-pass extraction of proton beam Multi-pass extraction of proton beam with short bent crystalswith short bent crystals

Short bent crystal - to deflect beam into septum apertureShort bent crystal - to deflect beam into septum apertureMagnet system - to extract beamMagnet system - to extract beam

IHEP-PNPI 1998

1212Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Requirements for crystalRequirements for crystal

Hight of working area Hight of working area ~5 mm~5 mm

Width of working area Width of working area ~1 mm~1 mm

Length along beam Length along beam 0.5-5 mm0.5-5 mm

Thickness of broken layer Thickness of broken layer ~0.001 mm~0.001 mm

Precision of orientation Precision of orientation ~0. ~0.33 mrad mrad

Bending angle Bending angle 1- 1-2 mrad2 mrad

1313Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

O-crystal designO-crystal design

TypicalTypical dimensionsdimensions 5 x 5 x 50 mm35 x 5 x 50 mm3

1414Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Samples of O-crystals prepared in PNPISamples of O-crystals prepared in PNPI

Crystal

5mm

Beam Direction

Crystal Courtesy of IHEP, Protvino

Slide taken from report to EPAC02 (Paris, France) on Crystal Collimation at RHIC

1515Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Typical interference pattern from a bent face of the O-crystals

1616Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Main results with O-crystals at Main results with O-crystals at IHEPIHEP

Length along beam 3-5 mmLength along beam 3-5 mm

Extraction efficiency 60-70%Extraction efficiency 60-70%

Intensity of extracted beam ~1x10Intensity of extracted beam ~1x101212

Radiation hardness ~10Radiation hardness ~102020

Still working with efficiency ~ 40%Still working with efficiency ~ 40%

1717Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

New approach – to use Sumbaev New approach – to use Sumbaev (elastic quasimosaic) effect(elastic quasimosaic) effect

Studied by Sumbaev in 1957Studied by Sumbaev in 1957Resulted in broadening of Resulted in broadening of gamma-ray diffraction peaks gamma-ray diffraction peaks from bent quartz platesfrom bent quartz platesCaused by bending of the Caused by bending of the reflecting atomic planes (initially reflecting atomic planes (initially flat and normal to large faces of flat and normal to large faces of plate) due to crystal anisotropy plate) due to crystal anisotropy Depends on choice of Depends on choice of crystallographic plane and crystallographic plane and orientation angle of plate cutting orientation angle of plate cutting relative to a normal to the relative to a normal to the chosen crystallographic planechosen crystallographic plane

Figure from article: O.I.Sumbaev, Reflection of gamma-rays from bent quartz plates, 1957

1818Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Crystal designCrystal design

1919Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Elastic quasimosaic in Elastic quasimosaic in ddependence on ependence on cut angle for Si (111) plancut angle for Si (111) planee

T – thickness of plate

k9 – deformation coefficient

= 2k9 T , where

Plate bending radius R = 1 m

2020Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Cut Cut = 0

2121Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Rocking curves for plate with cut angle = 0

before and after bending.

EExperiment with X-raysxperiment with X-rays

2222Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Experiment with protons at IHEPExperiment with protons at IHEP

2323Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Some details of experimental setupSome details of experimental setup

2424Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

First rFirst resultesult

2525Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Quasimosaic crystals prepared for U-70Quasimosaic crystals prepared for U-70

2626Yuri M.IvanovYuri M.Ivanov CC-2005, CERN, March 7-8, 2005 CC-2005, CERN, March 7-8, 2005

Some preliminaty results with Some preliminaty results with quasimosaic crystals at IHEPquasimosaic crystals at IHEP

Length along beam 0.3-10 mmLength along beam 0.3-10 mm

Extraction efficiency 70-80%Extraction efficiency 70-80%

Intensity of extracted beam 1-4 x 10Intensity of extracted beam 1-4 x 101212