X-ray and ?-ray polarimetry

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X-ray and ?-ray polarimetry

• Stanislav Tashenov
• KTH Stockholm

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Outline
Definitions
Photon Polarimetry - Short Overview
Compton Polarimetry of hard X-rays
Principle Klein-Nishina formula Pixel Detector
coincident technique
Experimental study of the polarization of
Radiative Recombination
From experimental setup till results
New developments of Compton polarimeters for
low energies (few 100 keV)
Extension of Compton polarimetry to higher
energies, tracking (till few 10 MeV)
Compton circular polarimetry
Other types of polarimeters
Photoelectric Pair production Crystalline
Summary
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What is photon polarization?
Classical polarization of electromagnetic waves
Quantum Mechanical photon helicity
linear
Linear polarization superposition of states
with opposite helicities
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What is partial photon polarization?
Mixed state is described by a density matrix
Stokes parameters
Linear polarization components
Circular
polarization ellipse
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Photon polarimetry imaging
Rayleigh (elastic) scattering
Bragg reflection
Linear dichroism
Photoabsorption
Birefringence effect
Thomson scattering
and Compton scattering
IR visible light UV
soft X-ray X-ray
hard X-ray gamma ?
energy, ev
CCD cameras
Micropattern gas counters
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Photon polarimetry imaging
energy, ev
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Photon polarimetry imaging
Pair production
Birefringence in CPP
energy, ev
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Outline
Definitions
Photon Polarimetry - Short Overview
Compton Polarimetry of hard X-rays
Principle Klein-Nishina formula Pixel Detector
coincident technique
Experimental study of the polarization of
Radiative Recombination
From experimental setup till Results
New developments of Compton polarimeters for
low energies (few 100 keV)
Extension of Compton polarimetry to higher
energies, tracking (till few 10 MeV)
Compton circular polarimetry
Other types of polarimeters
Photoelectric Pair production Crystalline
Summary
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Compton scattering
scattered photon
recoil electron
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Compton polarimetry
Klein-Nishina equation
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Segmented detectors coincidence technique
E hw
E DEel hw?
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Compton kinematics
scattered photon
recoil electron
For higher energies the reconstruction is more
difficult ? Tracking is required
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Outline
Definitions
Photon Polarimetry - Short Overview
Compton Polarimetry of hard X-rays
Principle Klein-Nishina formula Pixel Detector
coincident technique
Experimental study of the polarization of
Radiative Recombination
From experimental setup till results
New developments of Compton polarimeters for
low energies (few 100 keV)
Extension of Compton polarimetry to higher
energies, tracking (till few 10 MeV)
Compton circular polarimetry
Other types of polarimeters
Photoelectric Pair production Crystalline
Summary
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Radiative Recombination
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Photon Polarization
Photoionization
non-relativistic dipole approximation 100
polarization for all emission angles
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K-REC photon polarization
K-REC into bare uranium ions (U92 e- ? U91
h? )
non-relativistic dipole approximation 100
polarization for all emission angles
along the magnetic field
along the electric field
Large relativistic contributions
J. Eichler et al., PRA, 65 (2002) 052716 A.
Surzykov et al., Phys. Lett. A 289 (2001) 213 A.
Surzykov et al., PRA 68 (2003) 022710
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REC measurement at the ESR storage ring
SIS injection 400 MeV/u
e- cooler
U92 stored at energies of 98.4, 132.2,
190.0, 400.0 MeV/u Number of stored particles
1 to 3x108 Energy definition 10-4 with cooling
Particle detector
GAS JET
60o
90o
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Experiment Polarization Measurement for
Radiative Recombination Transitions (U92 e- ?
U91 h? )
K-REC
ESR storage ring
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Compton scattering angular distribution Internal
normalization
90? rotational symmetry of the detector
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Monte-Carlo simulation describing the detector
response to polarized light
Multiple Compton scattering
Compton profile
Rayleigh scattering
4 up to 12
Statistical error
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Results
Uranium (Z92)
Angular dependence

S. Tashenov et al., PRL 97 (2006) 223202
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Ion beam spin polarization
ion beam
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Outline
Definitions
Photon Polarimetry - Short Overview
Compton Polarimetry of hard X-rays
Principle Klein-Nishina formula Pixel Detector
coincident technique
Experimental study of the polarization of
Radiative Recombination
From experimental setup till results
New developments of Compton polarimeters for
low energies (few 100 keV)
Extension of Compton polarimetry to higher
energies, tracking (till few 10 MeV)
Compton circular polarimetry
Other types of polarimeters
Photoelectric Pair production Crystalline
Summary
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Further developments of Compton polarimeters
2D Si(Li) stripe detector 2 mm stripe width
Optimization for lower energies (60 keV)
stack of 10 DSSD 2 mm stripe width
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Further developments of Compton polarimeters
Increased segmentation for better polarization
sensitivity
2D Ge µ-stripe detector 0.25 x 1.2 mm stripe
width
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Further developments of Compton polarimeters
Pulse Shape Analysis 2D pixel detector with 10 mm
pixel size ? 1 3 mm 3D position resolution
3D position sensitivity achieved by means of
digital signal processing
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Outline
Definitions
Photon Polarimetry - Short Overview
Compton Polarimetry of hard X-rays
Principle Klein-Nishina formula Pixel Detector
coincident technique
Experimental study of the polarization of
Radiative Recombination
From experimental setup till results
New developments of Compton polarimeters for
low energies (few 100 keV)
Extension of Compton polarimetry to higher
energies, tracking (till few 10 MeV)
Compton circular polarimetry
Other types of polarimeters
Photoelectric Pair production Crystalline
Summary
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Extension to higher energies
Gamma-ray tracking is required
Solution BGO shielding or Close-packed geometry
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Tracking principle
How well do the scattering angles fit with the
corresponding deposited energies?
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Performance of tracking
initial spectrum
full energy events
escape events

• Tracking can
• determine the sequence of the scatterings
• verify the full energy deposition
• obtain the initial energy for the escape events

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Gamma arrays for nuclear physics based on
tracking principles
Application of linear polarization radiation
from aligned excited states - Identification of
electric and magnetic transitions g-factor
measurements time variation of linear
polarization
AGATA (EU) GRETA (US)
DESPEC (GSI, darmstadt)
J. Rikovska, Hyperf. Int. 24-26 (1985) 963 G.J.
Schmid et al., NIMA 417 (1998) 95
J. Simpson, J. of Phys. Conf. Ser. 41 (2006)
72-80 I.Y. Lee et al., Nucl. Phys. A 746 (2004)
255c-259c
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Gamma arrays for astrophysics
Gamma-ray polarization will be used to study
the emission processes in GRBs, pulsars, AGN,
and solar flaresopening a new dimension
in diagnostic phase space.
(27 layers of Si and 4 layers of Ge)
(12 Ge detectors)
Advanced Compton Telescope space mission
Nuclear Compton Telescope balloon-borne mission
S.E. Boggs, P. Jean, Astronomy and Astrophysics
376 (2001) 1126 J.D. Kurfess et al., New
Astronomy Reviews 48 (2004) 293
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Outline
Definitions
Photon Polarimetry - Short Overview
Compton Polarimetry of hard X-rays
Principle Klein-Nishina formula Pixel Detector
coincident technique
Experimental study of the polarization of
Radiative Recombination
From experimental setup till results
New developments of Compton polarimeters for
low energies (few 100 keV)
Extension of Compton polarimetry to higher
energies, tracking (till few 10 MeV)
Compton circular polarimetry
Other types of polarimeters
Photoelectric Pair production Crystalline
Summary
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Compton circular polarimetry
Circularly polarized light couples only to
spin-oriented electrons
k, k0 final and initial photon energies k, k0,
S photon and electron momenta
W.H.McMaster, Review of Modern Physics 33 No.1
(1961) 8
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Compton circular polarimetrytechnical
realization
2 out of 26 electrons of Fe can be spin oriented
for Compton scattering the opposite spins of
the electron and the photon are preferable
H. Schopper, Nuclear Instruments 3 (1958)
158 L.W. Fagg, S.S. Hanna, Review of Modern
Physics 31 No.3 (1959) 711
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Compton circular polarimetryexamples of
applications
Magnetic Compton scattering measurements of spin
distributions in magnetic research Thomson
scattering off relativistic electron beams to
determine its properties
Studies of parity violation and tests of the
standard model of elementary particles Neutrino
helicity (Goldhaber experiment) Astrophysics
light emission from strongly magnetized media
E.G. Adelberger, Ann. Rev. Nucl. Part. Sci. 35
(1985) 501 W.C. Haxton, C.E. Wieman, Annu. Rev.
Nucl. Part. Sci. 51 (2001) 261 L. N. Labzowsky et
al., PRA 63 (2005) 054105 M.J. Cooper et al.,
Radiation Physics and Chemistry 75 (2006) 1638 F.
Lei et al., Space Science Reviews 82 (1997)
309 J.C. Kemp, The Astrophysical Journal 162
(1970) 169
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Outline
Definitions
Photon Polarimetry - Short Overview
Compton Polarimetry of hard X-rays
Principle Klein-Nishina formula Pixel Detector
coincident technique
Experimental study of the polarization of
Radiative Recombination
From experimental setup till results
New developments of Compton polarimeters for
low energies (few 100 keV)
Extension of Compton polarimetry to higher
energies, tracking (till few 10 MeV)
Compton circular polarimetry
Other types of polarimeters
Photoelectric Pair production Crystalline
Summary
38
Photoelectric polarimeters
1 up to few 10 keV
E. Costa et al., Nature 411 (2001) 662 R.
Bellazzini et al., NIMA A 576 (2007) 183
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Photoelectric polarimeters
1 up to few 10 keV
non-relativistic dipole approximation 100
polarization for all emission angles
along the magnetic field
Cross over happens at much higher energies
R.P. Pratt et al., Polarization correlations in
atomic photoeffect, Phys. Rev. 134 No 4a (1964)
916
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Pair production polarimeters
few MeV up to 1 GeV
Problem at lower energies angle straggling of
electrons and positrons in solids
Solution Gas micro well detectors
P.F. Bloser et al., arXivastro-ph/0308331 (2003)
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Crystalline polarimeters
gt few GeV
N. Cabibbo, PRL 9 (1962) 270 N. Cabibbo, PRL 9
No10 (1962) 435
U. Uggerhoj Rev. Mod. Phys. 77 (2005) 1131 A.
Apyan et al., arXivhep-ex/0512017 v1 (2005)
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In collaboration with...
ESR
EBIT
nuclear ?-spec
...the end.
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X-ray polarimetry publications

• Bragg polarimetry
• P. Soffitta et al., "Techniques and detectors for
  polarimetry in X-ray astronomy" NIMA 510 (2003)
  170
• E.E. Alp et al., "Polarizeranalyzer optics"
  Hyperfine Interactions 125 (2000) 45
• P. Beiersdorfer et al., "Polarization of K-shell
  x-ray transitions of Ti19 and Ti20 excited by
  an electron beam" PHYSICAL REVIEW A 60 (1999)
  4156
• Photoelectric polarimetry
• R. Bellazzin et al., "A photoelectric polarimeter
  for XEUS a new window in x-ray sky"
  arXivastro-ph/0609571v1 (2006)
• E. Costa et al., "An efficient photoelectric
  X-ray polarimeter for the study of black holes
  and neutron stars" Nature 411 (2001) 662
• E. Costa et al., "OPENING A NEW WINDOW TO
  FUNDAMENTAL PHYSICS AND ASTROPHYSICS X-RAY
  POLARIMETRY" arXivastro-ph/0603399 (2006)
• J.K. Black et al., "X-ray polarimetry with an
  active-matrix pixel proportional counter" NIMA
  513 (2003) 639
• Compton polarimetry
• F. Lei et al., "Compton polarimetry in gamma-ray
  astronomy" Space Science Reviews 82 (1997)
  309388
• M.L. McConnell, J.M. Ryan "Status and prospects
  for polarimetry in high energy astrophysics" New
  Astronomy Reviews 48 (2004) 215219
• Hiroyasu Tajima et al.,"Gamma-ray Polarimetry
  with Compton Telescope" (2004) arXivastro-ph/0407
  114
• R.A. Kroeger et al., "Gamma ray polarimetry using
  a position sensitive germanium detector" NIMA 436
  (1999) 165
• L.W. Fagg "Polarization measurements on nuclear
  gamma rays" Review of Modern Physics 31 No3
  (1959) 711
• W. McMaster "Matrix representation of
  polarization" Review of Modern Physics 33 No1
  (1961) 8
• G.J. Schmid et al., "Gamma-ray polarization
  sensitivity of the Gammasphere segmented
  germanium detectors" NIMA 417 (1998) 95

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