Electron beam Møller polarimeter at hall A, JLab
As a part of the spin-physics program at the Thomas Jefferson National Accelerator Facility (JLab), a Møller polarimeter has been developed to measure the polarization of electron beam of energies between 0.8 and 6.0 GeV. A unique design of this polarimeter was developed. A set of three quadrupole m...
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2002
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| Cite this: | Electron beam Møller polarimeter at hall A, JLab / E.A. Chudakov, A.V. Glamazdin, V.G. Gorbenko, L.G. Levchuk, R.I. Pomatsalyuk, P.V. Sorokin // Вопросы атомной науки и техники. — 2002. — № 2. — С. 43-48. — Бібліогр.: 12 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860243770542391296 |
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| author | Chudakov, E.A. Glamazdin, A.V. Gorbenko, V.G. Levchuk, L.G. Pomatsalyuk, R.I. Sorokin, P.V. |
| author_facet | Chudakov, E.A. Glamazdin, A.V. Gorbenko, V.G. Levchuk, L.G. Pomatsalyuk, R.I. Sorokin, P.V. |
| citation_txt | Electron beam Møller polarimeter at hall A, JLab / E.A. Chudakov, A.V. Glamazdin, V.G. Gorbenko, L.G. Levchuk, R.I. Pomatsalyuk, P.V. Sorokin // Вопросы атомной науки и техники. — 2002. — № 2. — С. 43-48. — Бібліогр.: 12 назв. — англ. |
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| container_title | Вопросы атомной науки и техники |
| description | As a part of the spin-physics program at the Thomas Jefferson National Accelerator Facility (JLab), a Møller polarimeter has been developed to measure the polarization of electron beam of energies between 0.8 and 6.0 GeV. A unique design of this polarimeter was developed. A set of three quadrupole magnets provides an angular selection of the Møller electron pairs and a dipole magnet provides energy analysis. The test procedure and commissioning of the polarimeter are presented. The results of beam polarization measurements in long-term physical experiments, the correlation for the three-beam accelerator mode and other effects are discussed.
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E X P E R I M E N T A L M E T H O D S A N D P R O C E S S I N G O F D A T A
ELECTRON BEAM MØLLER POLARIMETER AT HALL A, JLAB
E.A. Chudakov2, A.V. Glamazdin1, V.G. Gorbenko1
L.G. Levchuk1, R.I. Pomatsalyuk1, P.V. Sorokin1
1National Science Center “Kharkov Institute of Physics and Technology”,
1 Academicheskaya Str., Kharkov, 61108, Ukraine
e-mail: gorbenko@jlab.org
2Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA
23606-4350, USA
As a part of the spin-physics program at the Thomas Jefferson National Accelerator Facility (JLab), a Møller
polarimeter has been developed to measure the polarization of electron beam of energies between 0.8 and 6.0 GeV.
A unique design of this polarimeter was developed. A set of three quadrupole magnets provides an angular selection
of the Møller electron pairs and a dipole magnet provides energy analysis. The test procedure and commissioning of
the polarimeter are presented. The results of beam polarization measurements in long-term physical experiments, the
correlation for the three-beam accelerator mode and other effects are discussed.
PACS: 13.88.+e, 29.27.Hj, 29.27.Fh
1. INTRODUCTION
Since 1996 JLab is the world's premier facility for
studying nuclei and nucleons via the (e,e'x) reactions
with a polarized electron beam. For the spin-physics
program at JLab, a number of polarimeters exploiting
Mott, Møller, and Compton scattering are used. In the
Hall A a Møller polarimeter was designed and
constructed to measure the polarization of the electron
beam with energies from 0.8 to 6 GeV. It has been
operating since 1998. The polarimeter was created
eliminating certain disadvantages which were inherent
in its predecessors. For example, the effect of Fermi
motion of atomic electrons [1-2] (now known as the
Levchuk-effect) was taken into account in the
polarimeter design. A rotatable polarized target and a
new method of target polarization measurements in situ
were developed for this polarimeter. The polarimeter
was used to measure the long-time evolution of the
beam polarization for a number of experiments in the
Hall A. Some of the experiments results are published
already [3-8]. The Møller polarimeter was used for
investigation of the dependencies of the electron beam
polarization on certain parameters of the RF system of
the injector at the JLab accelerator.
2. EXPERIMENTAL METHOD AND
RESULTS
2.1 Polarized electron beam at JLab
CEBAF (Continuous Electron Beam Accelerator
Facility) is the accelerator located at JLab in Newport
News, VA, USA. The accelerator is based on
superconducting RF cavities operating in a continuous
wave (CW) mode. A layout of the machine is shown in
Fig. 1 [9]. Two parallel linacs in a "race track"
configuration increase the beam energy from 800 to
1200 MeV for each turn. The beam is recirculated up to
five times to reach a maximum energy up to 6 GeV. The
accelerator can deliver electrons to 3 experimental areas
(Hall A, B and C) at either the same energy, or at
multiples of 1/5 of the end energy. The energy spread in
the beam is ∆E/E<10-4. Beams can be extracted at each
recirculation. It provides the operation of the
experimental halls with simultaneous beams of
different, but correlated, energies. The 1.497 GHz RF
structure allows simultaneous beams to be delivered to
the halls at a frequency of 499 MHz. The microbunches
can be loaded with different electron densities, which
provide operations of the experimental halls with in
parallel with a standard thermionic unpolarized gun.
Fig. 1. Schematics of the CEBAF accelerator [9]
The polarized electron gun produces a continuous
series of electron bunches at a characteristic RF of
1497 MHz of the accelerator. The polarized source is
based on the method of photoemission from
semiconductor photocathodes (strained GaAs type),
which induce an incident circularly polarized laser
beam. The laser system (see Fig. 2) comprises three
PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2002, № 2.
Series: Nuclear Physics Investigations (40), p. 43-48. 43
lasers, one designed to each experimental hall. Each
laser operates in a synchronized RF mode with
499 MHz frequency and produces optical pulses of
~55 ps duration (30oRF). The beam current for each hall
can be adjusted with corresponding photon beam
attenuators or slit devices. Usually, the photon
attenuators are fully open to minimize the current
dilution between different laser beams. The slit device
makes it possible to reduce the electron beam current
and its phase.
499 MHZ
SEED LASER
MIRROR
MIRROR
AMPLIFIER LASERLENSATTENUATOR
499 MHZ
SEED LASER
MIRROR
MIRROR
AMPLIFIER LASERLENSATTENUATOR
499 MHZ
SEED LASER
MIRROR
MIRROR
AMPLIFIER LASERLENSATTENUATOR
HALL A LASER
HALL B LASER
HALL C LASER
ELECTRON
GUN
MIRROR
MIRROR
BEAM
COMBINER
POLARIZED
BEAM
SPLITTER
FILTER
HALF-WAVE
PLATE
LENS POCKELS CELL
BENDING
MAGNET
SLIT
FARADEY
CUP
SPIN
ROTATOR
MOTT
DETECTOR
e
Fig. 2. Layout of the laser system and polarizing
optics [9]
2.2 The Hall A Møller polarimeter
The polarimeter exploits the process of Møller
scattering [10] e→+e→→e+e. Its cross-section depends
on the beam and target polarizations Pbeam and Ptarget as:
dσMoll/dΩ* = (dσo
Møll/dΩ*)×(1+Σ Pi
beamAii Pi
target), (1)
where i=x,y,z defines the projections of the
polarizations, and dσo
Møll/dΩ* is the cross-section of
non-polarized Møller scattering. The analyzing power
Aii depends on the scattering angle in the CMS frame Θ
CMS. Assuming that the beam direction is along the zaxis
and that the scattering happens in the zx plane:
dσMoll/ dΩ* = (α2γ-2 /4m2)×(4 - sin2Θ*)2/sin4Ω*, (2)
Azz = -(7 + cos2Θ*)sin2Θ*/(3 - cos 2 Θ*)2. (3)
At ΘCMS=90o the analyzing power has its maximum
(Azz)max=-7/9. A beam transverse polarization in the
scattering plane also leads to an asymmetry, though the
analyzing power is lower: (Axx)max=1/9. The main
purpose of the polarimeter is to measure the
longitudinal component of the beam polarization.
For the polarized electron target the Møller
polarimeter of Hall A (see Fig. 3) uses ferromagnetic
foils magnetized in a magnetic field of about
240 Oersteds along the beam axis. The target foil can be
tilted at various angles to the beam axes in the
horizontal plane; therefore the target polarization has
both longitudinal and horizontal transverse components.
The spin of the incoming electron beam may have a
horizontal transverse component due to precession in
the accelerator and in the extraction arc, coupling with
the target transverse polarization.
In order to cancel out the horizontal component, the
asymmetry is measured at two target angles of about
20º and 160º and the average is taken, since the
horizontal contributions have opposite signs for these
target angles. Additionally, this method reduces the
impact of uncertainties in the target angle
measurements. At a given target angle two sets of
measurements with opposite directions of the target
polarization are taken. Averaging the results helps to
cancel some false asymmetries, as one coming from the
residual helicity driven asymmetry of the beam flux.
The target polarization was derived from the foil
magnetization measurements. For the Supermendur foil
used in 19981999 a polarization of 7.95±0.23% was
obtained.
The Møller scattering events pass through a
magnetic spectrometer (see Fig. 3) consisting of a
sequence of three quadrupole magnets and a dipole
magnet to detector. The spectrometer selects the
electrons scattered close to the horizontal plane, in a
kinematical range of about 75°<ΘCMS<105°. The
polarimeter can be used at beam energies from 0.8 to
6 GeV, by setting the appropriate fields n the magnets.
The detector consists of lead-glass calorimeter modules,
split into two arms in order to detect two scattered
electrons in coincidence. The helicity asymmetry of the
coincidence counting rate (typically of about
105 counts/sec) is used to derive the beam polarization.
Additionally, for detecting the counting rates, about
300 counts/sec of "minimum bias", the events
containing the amplitudes and timings of all the signals
are recorded with a soft trigger from one arm. These
data are used for various checks and tuning, and also for
studying the non-Møller background. The ratio of the
single arm rate to the coincidence rate is about 2 for the
beam energy higher than 1.5 GeV, while it rises up to 5
at the lowest beam energy used of 0.8 GeV. A
comparison of the asymmetries measured with the
single arm signal and the coincidence indicates that
about 30% of the single arm rate is caused by nonMøller
sources. The estimated accidental rate level in
comparison with the coincidence rate is below 1%.
Fig 3. Layout of the Møller polarimeter, top
presents the side view, bottom presents the top view.
The trajectories displayed belong to a simulated event
44
of Møller scattering at ΘCMS=75° and ΘCMS=105°, at a
beam energy of 4 GeV
The polarimeter was used in all Hall A experiments
with polarized beam for the beam polarization
measurements. For the first experiments, when a bulk
GaAs photocathode was used in the polarized gun, a
typical beam polarization was ~35%, and for the
strained GaAs photocathode typical polarization it is of
about 75-80%. A typical statistical error for a 1 hour
measurement with the beam current of about 0.5 µA is
~0.2%, and the absolute systematic error is ~2.5%.
2.3 "Spin-dance" measurements
Let the particle's momentum to rotate by an angle Θ.
Then its spin would turn with respect to the momentum
by an angle:
α = γ×Θ×(g - 2)/2, (4)
where γ=E/m, Θ is an angle of the momentum rotation
and (g-2)/2 = 0.00115965 for electrons. So, spin turns to
the same direction as the momentum and by a larger
angle at higher energy.
The total expected spin rotation angle for the halls
A, B, C at CEBAF is calculated in [10]. The value of α
depends on the number of passes and on the angle in the
hall's extraction arcs, taking into account the beam
acceleration:
α=(EL/m)×(g-2)/2×(2n2-n×(1-2a+b))-
a×(1+b/2)×180°, (5)
where EL is the linac's energy, n is the number of passes,
m=0.51099906 MeV/c2 is the electron mass, a=0.1125
is the ratio of the injector energy to the linac's energy,
b=-1/2.4 for Hall A, =0 for Hall B and 1/2.4 for Hall C;
this factor comes from the extraction arc.
Let us assume Hall A is running five passes at
EL=0.55836 GeV, so Θ= 4.5×360°. Then spin makes an
angle of about 30.487×360° to the momentum.
Measuring the spin precession with an accuracy of 5°
one can potentially measure the electron energy with
accuracy on about 0.05%. However the initial spin angle
is not defined with a precision comparable to that and a
better way of measuring the spin precession is to
compare the synchronously measured beam
polarizations from two halls running at different
energies. This procedure is nicknamed "spin-dance".
The direction of spin is changed on the injector and by
convention the positive direction is clock-wise, as the
direction of accelerated electrons is. It is convenient to
run at a so-called "magic" energy when both halls
should have a zero transverse polarization at the same
angle at the injector. Since at the zero point the accuracy
of the phase measurement is the highest, both halls
should be able to measure this point at the same angle at
the injector.
The Hall A Møller polarimeter was cross-calibrated
by simultaneous measurement of the beam polarization
with three Møller polarimeters in halls A, B and C, the
Compton polarimeter at the Hall A and the Mott
polarimeter of the injector [12]. The results of the spin-
dance are presented on a Fig. 4 and Tables 1 and 2.
Experimental data were fitted with a curve: P(1)×sin((x-
P(2))×π/180°n), where n is a number of the beam passes
Table 1. Final results of spin-dance measurement
for Einjector = 0.06289 GeV and Elinac = 0.55836 GeV. 1-
Mott (injector), 2-Compton (Hall A), 3 Møller (Hall A),
4- Møller (Hall B), 5- Møller (Hall C)
Pola-
rimetr
Total precession
angle, degrees
Phase,
degrees
Polari-
zation,*%
1 0. 88.79±0.34 72.22±0.21
2 10975.2 -175.79±0.75 72.52±0.45
3 10975.2 -176.12±0.62 75.50±0.14
4 10494.7 60.41±0.51 69.33±0.48
5 10014.2 -56.95±0.63 73.60±0.23
* - only statistical errors of the electron beam
polarization measurement are presented.
Table 2. Summary of energy measurement results
comparing only end-station polarimeters [12]
Polari-
meters
∆α
degrees
Beam energy,
E, MeV ∆Ε/Ε
Møller A -
Møller B
+37.4908±0.0100 5685.67±9.531.68±10-3
Møller A -
Møller C
+74.9687±0.0046 5650.71±5.199.18±10-4
Compton A
- Møller B
+37.4908±0.0100 5689.55±10.8
1
1.90±10-3
Compton A
- Møller C
+74.9687±0.0046 5652.65±5.771.02±10-3
Møller B -
Møller C
+37.4779±0.0110 5615.75±9.671.72±10-3
in the accelerator. Parameters P(1) and P(2) are
presented on the Fig. 4.
All measurements and calculations were done for the
injector energy Einjector=0.06289 GeV and the linac
energy Elinac=0.55836 GeV. All three halls were running
with the same beam energy.
The angle shift ∆α between the dial and measured
angles is explained by the energy shift ∆E. As it is
shown in the Table 2, ∆E is approximately the same for
all halls and it is not proportional to the electron beam
energy. It means that the angle shift ∆α is connected to
the error in the injector energy definition, which is the
same for all three halls.
2.4 Laser's phase influence on the polarization
The electron beam in the injector with energy
5 MeV is deflected and rotated around a ring in the
plane perpendicular to the beam direction,
synchronously with RF of the accelerator and the
polarized injector laser RF structure (~500 MHz). An
absorber disk is placed in this plane, with 3 radial slits
for each hall's phase. This system, called a "choper",
provides the RF structure even for a DC and
unpolarized electron sources.
45
It was found that the polarization measured may
depend on the slit-attenuator configuration in the
injector. Typical Hall A experiments were running with
46
Fig. 4. Results of spin precession measurement with five polarimeters
Fig. 5. Hall A electron beam polarization dependence of the injector laser phase
the slit completely open and no laser attenuation while
the Møller measurements typically used configurations
with the slit tight and no attenuation. The latter was
done in order to minimize "cross-talks" (see 2.5) from
the lasers of Halls B,C running at a phase opposite to
Hall A laser. Additional important parameter of the
polarized gun is "phase". With a narrow slit the "phase"
defines what time phase of the laser RF pulse comes
through the slit, which may vary from the maximum of
the pulse to a tail, while with the open slit practically all
the pulse passes through whatever is the "phase"
parameter. The "phase" was readjusted 2-3 times per
week.
The influence of the phase adjustment on the
polarization was measured at the conditions as follows:
— for a given combination of attenuation, slit and phase
parameters. six Møller runs were taken, for the
polarization and the beam rate the average values were
calculated;
— for the measure of the beam intensity the 2-arm
coincidences of the Møller setup were used;
— the cross-talk from the laser B and C was measured
by turning the laser A off.
The results are presented on a Fig. 5 which shows:
1. The Møller coincidence rates depending on the
phase, for the slit parameters of 16.4 and 17.3 (in
arbitrary units. The higher value is the wider slit. At
16.4 the measurements were done at attenuations of 500
and 300 (in arbitrary units). The lower value of
attenuator parameter corresponds to stronger laser beam
attenuation. The results were all normalized to 300,
while at 17.3 the measurements were done at
attenuation 250. For the narrower slit of 16.4 the shape
of the peak is sharper than for the wider 17.3 slit.
2. The relative cross-talk from the lasers B and C
depends on the phase. The results were corrected for
this "cross-talk".
3. The beam polarization is flat on the peak top but
drops by about 10% at the tail of the peak. Therefore, if
during the Møller measurements the phase is adjusted to
the tail of the peak, the results should be systematically
lower than the average for the whole distribution.
4. The beam current in the injector was measured the
next day. For some reason the peak became broader and
a phase shift occurs with respect to the previous day.
5. This plot shows the beam current, measured on
the injector, depending on the slit parameter. The phase
was at -14o - at the top of the beam current profile. The
open and filled circles present the data taken at the laser
attenuation of 500 and 600. The data were approximated
with a polynomial with the coefficients as follows:
0.32209, -0.01468, 0.29857, 0.21897, -0.09835.
6. This plot shows the relative beam current,
measured on the injector, depending on the laser
attenuation. Since the measurements were done at
different slit sizes, the results were normalized to a
certain slit size using the polynomial defined in 5). The
data can be approximated with a curve a×sin((x-x0)×π
/(2×550))2, with x0=0. The beam current dependence on
the laser power parameter was not calibrated.
A potential source of systematic errors was found,
associated with the fact that Møller polarimeter
typically runs at a beam current of about 1% of the
current used by the experiments. There are two
reasonable ways to reduce the current to such a low
value:
1. Attenuate the laser beam
2. Attenuate the electron beam using a slit with a
variable width.
The 1-st method is not acceptable if the other halls
are running because of a considerable "cross-talk" from
the dark currents of the other lasers, typically polarized
in a direction, opposite to the laser of Hall A. At no
attenuation the effect of the cross-talk is below 0.1%,
but may reach a few per cent at a strong attenuation.
The second method looks preferable, but one has to be
sure that the narrow slit selects the plateau of the laser
RF structure, but not a tail where the beam polarization
is lower by 4-10%. The "phase" parameter of the
injector setup is used for appropriate adjustments.
2.5 "Cross-talk" between the halls
Separation of the beam between the halls is
performed using the RF phase of the electron bunches.
This phase matches the RF phase of the laser in the
given hall (see Fig. 2). In the process of the electron
beam polarization measurement with the Hall A Møller
polarimeter a strong "cross-talk" from the halls B and C
was found. This effect can be explained by the dark
currents of the halls B and C lasers. A sign of hall A
laser helicity is opposite to the sign of halls B and C.
Thus, the polarized electrons emitted with the hall B and
C lasers have an opposite sign of the polarization and
can reduce the Hall A electron beam polarization. The
leakage from halls B and C was measured by turning the
hall A laser off. The results of the measurements are
presented in the Table 3.
Table 3. Results of measurements of Hall B and C
laser beam leakage to Hall A
Run Polari-
zation,*%
Current,
µA
Comments
1 67.95±0.18 0.55 Lasers A, B, C are on
2 72.03±0.19 0.55 Lasers A, B are on,
laser C is off
3
-74.08±1.0 0.02 Laser A is off,
lasers B, C are on
4
- 0.00015 Laser A, C are off,
laser B is on
*- only statistical errors of the beam polarization
measurements are presented
During the regular electron beam polarization
measurements in the Hall A care is taken in order to
minimize the effect of the "cross-talk", using the
optimal combination of the laser attenuation and slit
size.
3. CONCLUSIONS
The Hall A Møller polarimeter is operating from
1997 for the electron beam polarization measurement. It
provides:
— the electron beam polarization measurement with the
relative systematic error <3%;
— control of long-time beam polarization evolution
along the experiments with high statistical accuracy of
~0.2%;
— measurement of both, longitudinal and transverse,
components of the beam polarization;
— measurement of each component of the polarized
beam helicity;
— control of the beam energy with accuracy of ~10-4
together with another hall polarimeters;
— investigation of phase- and time-resolved properties
of the polarized electron beam together with polarized
injector.
The JLab injector system design offers additional
advantages to investigate the phase-resolved effects, and
also the synchronization pulse delay for generating a
laser pulse for any of three halls in the relation to the
time pulse of the accelerator RF-structure. The use of
the minimal slit size, which corresponds to the electron
bunch duration of about 0.5 psec, permits high time-
resolution investigations of the time structure of
electron bunches. The preliminary results of these
investigations were obtained. The beam current and
polarization were studied as functions of the laser
attenuation and slit position for the Møller polarimeter
current range. The effects of "cross-talk" between the
lasers of three halls were investigated. The data analysis
is now in progress and additional measurements are
desirable. Simultaneous measurement of the beam
polarization with different spin orientations gives an
additional control of the spin orientation and makes it
possible to measure the beam energy with accuracy of
about ~10-4.
ACKNOWLEDGMENTS
We thank J.M. Grames for the important information
about the accelerator and the polarized injector. This
work was supported in part by INTAS grant INTAS-99-
125, by CRDF grant UP2-2271 and by contract of
Ukrainian State Foundation of Fundamental Researches
No 9.02.01/064-93 and No 2.5.1/27. This work was
supported by the United States Department of Energy
contract DE-AC05-84ER40150 under which the
Southeastern Universities Research Association
(SURA) operates the Thomas Jefferson National
Accelerator Facility.
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|
| id | nasplib_isofts_kiev_ua-123456789-80112 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-07T18:33:42Z |
| publishDate | 2002 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Chudakov, E.A. Glamazdin, A.V. Gorbenko, V.G. Levchuk, L.G. Pomatsalyuk, R.I. Sorokin, P.V. 2015-04-11T19:46:17Z 2015-04-11T19:46:17Z 2002 Electron beam Møller polarimeter at hall A, JLab / E.A. Chudakov, A.V. Glamazdin, V.G. Gorbenko, L.G. Levchuk, R.I. Pomatsalyuk, P.V. Sorokin // Вопросы атомной науки и техники. — 2002. — № 2. — С. 43-48. — Бібліогр.: 12 назв. — англ. 1562-6016 PACS: 13.88.+e, 29.27.Hj, 29.27.Fh https://nasplib.isofts.kiev.ua/handle/123456789/80112 As a part of the spin-physics program at the Thomas Jefferson National Accelerator Facility (JLab), a Møller polarimeter has been developed to measure the polarization of electron beam of energies between 0.8 and 6.0 GeV. A unique design of this polarimeter was developed. A set of three quadrupole magnets provides an angular selection of the Møller electron pairs and a dipole magnet provides energy analysis. The test procedure and commissioning of the polarimeter are presented. The results of beam polarization measurements in long-term physical experiments, the correlation for the three-beam accelerator mode and other effects are discussed. We thank J.M. Grames for the important information about the accelerator and the polarized injector. This work was supported in part by INTAS grant INTAS-99-125, by CRDF grant UP2-2271 and by contract of Ukrainian State Foundation of Fundamental Researches No 9.02.01/064-93 and No 2.5.1/27. This work was supported by the United States Department of Energy contract DE-AC05-84ER40150 under which the Southeastern Universities Research Association (SURA) operates the Thomas Jefferson National Accelerator Facility. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Experimental methods and processing of data Electron beam Møller polarimeter at hall A, JLab Мёллеровский поляриметр для электронного пучка в зале А ДжЛаб Article published earlier |
| spellingShingle | Electron beam Møller polarimeter at hall A, JLab Chudakov, E.A. Glamazdin, A.V. Gorbenko, V.G. Levchuk, L.G. Pomatsalyuk, R.I. Sorokin, P.V. Experimental methods and processing of data |
| title | Electron beam Møller polarimeter at hall A, JLab |
| title_alt | Мёллеровский поляриметр для электронного пучка в зале А ДжЛаб |
| title_full | Electron beam Møller polarimeter at hall A, JLab |
| title_fullStr | Electron beam Møller polarimeter at hall A, JLab |
| title_full_unstemmed | Electron beam Møller polarimeter at hall A, JLab |
| title_short | Electron beam Møller polarimeter at hall A, JLab |
| title_sort | electron beam møller polarimeter at hall a, jlab |
| topic | Experimental methods and processing of data |
| topic_facet | Experimental methods and processing of data |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/80112 |
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