Orientation effects in ultrarelativistic electron transmission through a single crystal
The results of experimental investigations of the 1.2 GeV electron transmission dynamics in a thin single crystal of Si are discussed. The interpretation of the electron scattering orientation dependencies measured under different scattering angles is carried out. The existence of scattering directi...
Saved in:
| Published in: | Вопросы атомной науки и техники |
|---|---|
| Date: | 2001 |
| Main Authors: | , , , , |
| Format: | Article |
| Language: | English |
| Published: |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2001
|
| Subjects: | |
| Online Access: | https://nasplib.isofts.kiev.ua/handle/123456789/79472 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Journal Title: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Cite this: | Orientation effects in ultrarelativistic electron transmission through a single crystal / S.V. Blazhevich, G.L. Bochek, V.I. Kulibaba, N.I. Maslov, B.I. Shramenko // Вопросы атомной науки и техники. — 2001. — № 6. — С. 144-146. — Бібліогр.: 5 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860257559661772800 |
|---|---|
| author | Blazhevich, S.V. Bochek, G.L. Kulibaba, V.I. Maslov, N.I. Shramenko, B.I. |
| author_facet | Blazhevich, S.V. Bochek, G.L. Kulibaba, V.I. Maslov, N.I. Shramenko, B.I. |
| citation_txt | Orientation effects in ultrarelativistic electron transmission through a single crystal / S.V. Blazhevich, G.L. Bochek, V.I. Kulibaba, N.I. Maslov, B.I. Shramenko // Вопросы атомной науки и техники. — 2001. — № 6. — С. 144-146. — Бібліогр.: 5 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | The results of experimental investigations of the 1.2 GeV electron transmission dynamics in a thin single crystal of Si are discussed. The interpretation of the electron scattering orientation dependencies measured under different scattering angles is carried out. The existence of scattering direction, where one can observe the scattering intensity independence on the crystallographic plane orientation is shown. Besides the existence of crystallographic axis orientation, where one can observe the region of uniform angle distribution of scattering intensity, is shown.
|
| first_indexed | 2025-12-07T18:50:49Z |
| format | Article |
| fulltext |
ORIENTATION EFFECTS IN ULTRARELATIVISTIC ELECTRON
TRANSMISSION THROUGH A SINGLE CRYSTAL
S.V. Blazhevich a, G.L. Bochek b, V.I. Kulibaba b, N.I. Maslov b, B.I. Shramenko b
a-Laboratory of Radiation Physics, Belgorod State University, Belgorod, Russia
b-National Science Center “ Kharkov Institute of Physics and Technology”, Kharkov, Ukraine
The results of experimental investigations of the 1.2 GeV electron transmission dynamics in a thin single crystal
of Si are discussed. The interpretation of the electron scattering orientation dependencies measured under different
scattering angles is carried out. The existence of scattering direction, where one can observe the scattering intensity
independence on the crystallographic plane orientation is shown. Besides the existence of crystallographic axis
orientation, where one can observe the region of uniform angle distribution of scattering intensity, is shown.
PACS:05.45.+b; 29.27Ac
INTRODUCTION
Experimental research of the passing dynamics of
electrons with the energy about 1 GeV into a crystal
represents an interest because the opportunity to use the
clearly classical approach for its description [1-3]. On
the other hand under such energies the relativistic
phenomena manifests brightly in transmission,
scattering and radiation processes.
In the present work the results of experimental
researches of orientation effects in ultrarelativistic
electron scattering in a Si single crystal are presented.
The experiments was carried out on LUE-2000 MeV
accelerator of NSC "Kharkov Institute Physics and
Technology".
The experiments on electron scattering have been
carried out by the typical measurement scheme. A
single crystal target was housed into evacuated chamber
with an goniometer which permits to orient the target in
relation to the axis of projectile electron beam with the
accuracy of 5⋅10-5 radian. The electrons transmitted
through target was detected by a diminutive Ge detector
(of 0.5x0.5 мм2 size) situated at a distance of about 15
meters from the target, what corresponds to a solid
angle near 1⋅10-9 sr. The angle distribution of the
scattered particles was measured by the detector
scanning the scattered beam in transverse plane. In
present work the dependence of the angle flux density
distribution of the scattered electrons was measured on
the given atomic axis and (or) plane orientation in
crystal.
1. TRANSMISSION OF ELECTRONS AT
A SMALL ANGLE TO A
CRYSTALLOGRAPHIC AXIS
The experimental investigations of the passage of
ultrarelativistic electrons through a thin single-crystal
target were set up on the 1.2 GeV electron beam. The 10
µm Si monocrystal cut along the (111) plane was used
as a target. The incident electron beam was collimated
to a diameter of 0.3 mm and had a measured divergence
of 10-5 radian. By means the detector fixed on the beam
axis the orientation dependencies of the scattered
electrons transmission was measured. The electron
transmission dependence on orientation relative to
<111> crystallographic axis is shown in Fig. 1. Here the
narrow angle region near direction of the projectile
beam axis is shown. The transmission intensity is
presented as the ratio to transmission intensity through
disoriented target. In the same figure the results of the
calculations are presented. A strong scattering effect is
manifested at the range of the small angles (forward
transmission intensity IΨ << 1). The coherent effects in
interaction processes of the fast charged particle with
the ordered atomic media manifest most brightly in thin
crystals. In this case, a new feature is observed as a
local minimum of electron transmission intensity at the
range of the small orientation angles, which is similar to
well known blocking effect.
Fig. 1. The dependence of transmission of 1.2 GeV
electrons through 10 µm Si single crystal on <111>
axis orientation. Registration solid angle is ~10-9 sr.
Solid curve denoted the results of the experiment.
Circles denote the result of the calculation taking into
account only the azimuthal scattering on atomic strings.
Squares denote the result of the calculation taking the
scattering of electrons on azimuth and polar angle
Other peculiarity of the measured orientation
dependence of forward transmission intensity show the
comparison with calculated one in the theoretical model
of relativistic electron azimuthal multiple scattering on
atom chains in crystal [1].
144 PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2001, № 6, p. 144-146.
It turns out that calculation gives significantly more
flat transmission intensity dependence on
crystallographic axis orientation angle than measured in
the experiment (see Fig. 1, circles). The qualitative
explanation of this disagreement was provided by taking
into account the particle scattering by polar angle,
which leads to additional suppression of transmission
intensity in the small region of orientation angles [2].
Taking to account of the particle polar angle scattering
leads to dependence, shown in Fig. 1 by squares.
The results of the electron transmission (curve 1)
and scattering (curves 2-8) intensity measured in a small
solid angle at different angles in the plane normal to
axis of crystal target rotation are presented in Fig. 2 and
Fig. 3. The results presented in Fig. 2 are obtained with
the use of the 10 µm Si single crystal as a target on the
electron beam of 500 MeV. For comparison in the Fig. 3
are presented a similar results obtained early on the
electron beam of 760 MeV under using Si single crystal
of 80 µm thickness and significantly worse angular
discrimination (1.2⋅10-8 steradian).
Fig. 2. The dependence of transmission and
scattering of 500 MeV electrons through 10 µm Si
single crystal on <111> axis orientation. Registration
solid angle is ~10-9 sr. The average electron multiply
incoherent scattering angle θs =0.15 mrad. The
scattering angles θ, mrad: 1 – 0; 2 – 0.08; 3 – 0.12; 4 –
0.16; 5 – 0.18; 6 – 0.23; 7 – 0.27; 8 –0.3
It is worthy of note that the transmission intensity
relation axis to random crystal orientation sharply
depends on measure angular discrimination. The
relation of electron transmission intensity through a
crystallographic axis oriented and disoriented crystal is
noteworthy. The typical curve of the transmission
intensity dependence vs the crystallographic axis
orientation has a local maximum (under crystallographic
axis aligned along the projectile beam axis, i.e. θ = 0)
comparable with the electron transmission intensity
through disoriented crystal. But the measure of high
angular discrimination gives much lower maximum.
This fact is in a close accordance with azimuth multiple
scattering concept. As may be seen from the diagrams
Fig. 2 and Fig. 3, there is such crystal orientation, which
results in confluence of all orientation curves, which is
to say that a scattering angle region of uniform intensity
distributions is being under this crystal orientation.
Fig. 3. The dependence of transmission and
scattering of 760 MeV electrons through 80 µm Si
single crystal on <111> axis orientation. Registration
solid angle is 1.2⋅10-8 sr. The scattering angles θ,
radian: 1 –0; 2-0.17⋅10-3; 3- 0.34⋅10-3; 4- 0.51⋅10-3;
5- 0.65⋅10-3; 6- 0.80⋅10-3; 7- 0.89⋅10-3; 8- 1.03⋅10-3
2. ELECTRON PASSING AT SMALL
ANGLES TO CRYSTALLOGRAPHIC
PLANE
In this section the results of the orientation
dependence measurements of the 1200 MeV electron
transmission and scattering intensity on (110) atomic
planes in 10 µm Si single crystal are presented. The
crystal was so aligned (see in Fig. 4) that axis of rotation
of crystal in goniometer is in (110) plane of the crystal
and both the orientation angles Ψ and observation
angles θ lie in plane perpendicular to plane (110). The
measurements were carried out by the same scheme and
with using the same detector which are described above.
The results are shown in Fig. 5. As may be seen from
the diagram, electron transmission forward into small
solid angle is minimal when crystal is oriented by a
crystallography plane along projectile beam axis, i.e. the
electron beam passing along the atomic planes are
scattered more than one passing at an angle to the
planes. It is seen also that in the crystal aligned by an
atomic plane along the projectile electron beam the
electrons scattering turn out symmetrically to the plane.
The intensity of the electron scattering to certain angle θ
> θs, (where θs – electron multiple scattering angle in
random crystal orientation) in the range of small
orientation angles ψ is higher than the in case of strong
disorientation of crystal. The maximum intensity
position do not coincide with the value of the
orientation angle ψ, i.e. orientation dependence became
allokurtic (asymmetric) in relation to orientation ψ=0.
This effect was observed also by authors of work [4]
and was named “quasiscattering effect”. The
explanation of this effect was done theoretically as the
result of joint action of the incoherent multiple
scattering and channeling in work [5].
As may be seen from Fig. 5, the scattering intensity
at scattering angle θ*≈θs practically do not depend on
145
crystal orientation, that can be used in measurements for
control of beam current.
Fig. 4. The geometry of the experiment on
orientation dependence of 1200 MeV electron
transmission (scattering angle θ = 0) and scattering (θ
≠ 0) incident at small angles ψ to crystallographic
plane
Fig. 5. The dependencies of 1200 MeV electron
transmission and scattering in the 10 µm Si crystal into
small solid angle ∆Ω = 10-9 sr vs ψ of (110) plane
orientation for the observation (scattering) angles θ: 1-
0; 2-0.047; 3-0.067; 4-0.084; 5-0.103; 6-0.13; 7-
0.148; 8-0.186; 9-0.231; 10-0.273 mrad
3. ELECTRON FORWARD
TRANSMISSION UNDER PLANE
CHANNELING CONDITIONS
Such a result obtained by the specific measurements
is presented in this paragraph. In preparations for the
experiment on the measurements the axis of the crystal
rotation was located normal to projectile beam direction
axis and crystallographic axis <111> located in plane of
crystal rotation. The dependence of electron
transmission intensity on crystal rotation angle ψ are
shown in Fig. 6 for different values of the orientation
angle α between the normal to a crystallographic plane
and crystal revolution axis.
The lower curve is in accord with coincidence the
atomic plane normal with the crystal rotation axis (α
=0). In this case the crystal rotation do not change the
position of the atomic plane normal. The “disordered
orientation” in this case remains indeed as the plane
aligned orientation and related intensity turn out lower
then under real disordered orientation (the top curve).
At small α angle value (second and third curves
from below) the plane orientation change are observed
as a wide trough on the orientation dependence.
CONCLUSIONS
Experimental research of the ultrarelativistic
electron transmission and scattering presented in the
work displays a row of the most characteristic
orientation effects, including such a new effects as
blockage of the forward electron transmission,
asymmetry of the electron scattering on atomic planes.
The obtained result can be applies both to dynamics of
the fast charged particles in crystals and to processes
tightly bound with dynamics, namely photon radiation
processes, pair production, nuclear reaction in crystal.
Fig. 6. The (110) plane manifestation in orientation
dependence of 500 MeV electron transmission through
thin Si crystal at small angles to <111> axis. The
registration solid angle ∆Ω =10-8 sr
ACKNOWLEDGMENT
The authors acknowledge the financial support from
the Russian Foundation for Basic Research under grant
№ 00-02-17523 and Ukraine Ministry of Education and
Science “Program of the works on atomic science and
technique” NSC KIPT, 2001-2002, project №04/32.
REFERENCES
1. V.I. Truten’, S.P. Fomin, N.F. Shul’ga. Orientation
effects in relativistic particles scattering in single
crystals. Preprint KIPT AS UkSSR, Kharkov, KIPT,
32-11, 1982, p. 28 (in Russian).
2. S. Blazhevich, G. Bochek, V. Kulibaba et al. The
relativistic electron passing through the thin Si
single crystal. Proc. XXI Vsesoyuzn. sov. po fiz.
vzoim. zar. chastiz s kristallasmi, M. izd MGU,
1992, p. 9-11 (R).
3. D. Adejshvili, A. Antipenko, S. Blazhevich et al.
Experimental research of the 760 MeV electron
scattering in Si crystal // JETP. 1987, 92, vyp. 5,
p. 1574-1577 (in Russian).
4. B. Ermak, S. Kas’yan, V. Kohnyuk, V. Noga,
V. Sanin. Quasiscattering of electron beam by Si
monocrystal // VANT, ser. Yad. Fiz. Issledovaniya
146
(theory and experiment). 1990, vyp. 3(11), p. 18-21
(R).
5. S. Fomin. Angular distribution of electrons through
oriented by plane thin crystal. Tezisy Dokl. XX
Vsesoyuzn. sov. po fiz. vzaim. zar. chastic s krist.
M.: izd. MGU, 1990, p. 34 (in Russian).
147
INTRODUCTION
1. TRANSMISSION OF ELECTRONS AT A SMALL ANGLE TO A CRYSTALLOGRAPHIC AXIS
2. ELECTRON PASSING AT SMALL ANGLES TO CRYSTALLOGRAPHIC PLANE
3. ELECTRON FORWARD TRANSMISSION UNDER PLANE CHANNELING CONDITIONS
CONCLUSIONS
ACKNOWLEDGMENT
REFERENCES
|
| id | nasplib_isofts_kiev_ua-123456789-79472 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-07T18:50:49Z |
| publishDate | 2001 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Blazhevich, S.V. Bochek, G.L. Kulibaba, V.I. Maslov, N.I. Shramenko, B.I. 2015-04-02T15:06:12Z 2015-04-02T15:06:12Z 2001 Orientation effects in ultrarelativistic electron transmission through a single crystal / S.V. Blazhevich, G.L. Bochek, V.I. Kulibaba, N.I. Maslov, B.I. Shramenko // Вопросы атомной науки и техники. — 2001. — № 6. — С. 144-146. — Бібліогр.: 5 назв. — англ. 1562-6016 PACS:05.45.+b; 29.27Ac https://nasplib.isofts.kiev.ua/handle/123456789/79472 The results of experimental investigations of the 1.2 GeV electron transmission dynamics in a thin single crystal of Si are discussed. The interpretation of the electron scattering orientation dependencies measured under different scattering angles is carried out. The existence of scattering direction, where one can observe the scattering intensity independence on the crystallographic plane orientation is shown. Besides the existence of crystallographic axis orientation, where one can observe the region of uniform angle distribution of scattering intensity, is shown. The authors acknowledge the financial support from the Russian Foundation for Basic Research under grant № 00-02-17523 and Ukraine Ministry of Education and Science “Program of the works on atomic science and technique” NSC KIPT, 2001-2002, project №04/32. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Electrodynamics of high energies in matter and strong fields Orientation effects in ultrarelativistic electron transmission through a single crystal Ориентационные эффекты при прохождении ультрарелятивистских электронов через монокристалл Article published earlier |
| spellingShingle | Orientation effects in ultrarelativistic electron transmission through a single crystal Blazhevich, S.V. Bochek, G.L. Kulibaba, V.I. Maslov, N.I. Shramenko, B.I. Electrodynamics of high energies in matter and strong fields |
| title | Orientation effects in ultrarelativistic electron transmission through a single crystal |
| title_alt | Ориентационные эффекты при прохождении ультрарелятивистских электронов через монокристалл |
| title_full | Orientation effects in ultrarelativistic electron transmission through a single crystal |
| title_fullStr | Orientation effects in ultrarelativistic electron transmission through a single crystal |
| title_full_unstemmed | Orientation effects in ultrarelativistic electron transmission through a single crystal |
| title_short | Orientation effects in ultrarelativistic electron transmission through a single crystal |
| title_sort | orientation effects in ultrarelativistic electron transmission through a single crystal |
| topic | Electrodynamics of high energies in matter and strong fields |
| topic_facet | Electrodynamics of high energies in matter and strong fields |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/79472 |
| work_keys_str_mv | AT blazhevichsv orientationeffectsinultrarelativisticelectrontransmissionthroughasinglecrystal AT bochekgl orientationeffectsinultrarelativisticelectrontransmissionthroughasinglecrystal AT kulibabavi orientationeffectsinultrarelativisticelectrontransmissionthroughasinglecrystal AT maslovni orientationeffectsinultrarelativisticelectrontransmissionthroughasinglecrystal AT shramenkobi orientationeffectsinultrarelativisticelectrontransmissionthroughasinglecrystal AT blazhevichsv orientacionnyeéffektypriprohoždeniiulʹtrarelâtivistskihélektronovčerezmonokristall AT bochekgl orientacionnyeéffektypriprohoždeniiulʹtrarelâtivistskihélektronovčerezmonokristall AT kulibabavi orientacionnyeéffektypriprohoždeniiulʹtrarelâtivistskihélektronovčerezmonokristall AT maslovni orientacionnyeéffektypriprohoždeniiulʹtrarelâtivistskihélektronovčerezmonokristall AT shramenkobi orientacionnyeéffektypriprohoždeniiulʹtrarelâtivistskihélektronovčerezmonokristall |