References - Bogoliubov Laboratory of Theoretical Physics - JINR

Figure 1: Layout of experiment
target-analyzer T 2 placed near the focus F 5. Magnetic lenses and dipoles are designated
as L1,L2,L3andM1,M2,M3. The part of the magnetic-optical channel behind the
target T 1uptoF5was tuned to the momentum of ∼ 5GeV/c, andthepartbehindF5 was tuned to 3.3 GeV/c.
The momenta of the deuterons extracted from the accelerator were adjusted to be
exactly 5.0 GeV/c at the exit from T 1 with allowance for ionization losses in the target
T 1. The measurements without the target T 1 were also periodically made. The intensity
of the beam was monitored by the ionization chambers placed near to the foci F 3,F4
and F 5. The intensity of the secondary beam between F 4andF5was5× 106 − 3 × 107 particles per beam spill.
Before the June 2008 run of the Nuclotron the layout of experiment was modernized
as follows: 1) an the additional five-electrode ionization chamber was placed behind the
target T 1 to control the position and intensity of the beam at the entrance to the doublet
of lenses L1; 2) the intensity of the beam incident on the target T 2 was monitored by
two telescopes of the scintillation counters located in the back hemisphere relative to the
target T 2 at the angles of 150◦ (M1) and 210◦ (M2).
The tensor polarization of the deuteron beam that passed through the target T 1at0◦ was determined by means of the deuteron stripping reaction on the 8-cm thick beryllium
target T 2 placed near F 5 [5]. The fact that the reaction d +A → p + X for proton
emission at the zero angle with the momentum pp ∼ 2
3pd has the known tensor analyzing
power T20 = −0.82 ± 0.04 [6] was used. If the differential cross sections of this reaction
in the case of the unpolarized and polarized deuteron beams are designated as σ0 and σ ′
respectively, the following relation for the tensor polarization pZZ holds [4, 7]:
√
2
� ′ σ
pZZ =
T20
σ0
�
− 1 , (1)
where the axis of quantization coincides with the direction of protons emitted forward.
The secondary particles emitted from the target T 2at0 ◦ were directed to the focus F 6
by bending magnets and magnetic lenses. The momentum and polar angle acceptances
of the setup determined by the Monte Carlo simulation were Δp/p ∼±2% and ±8 mrad,
respectively.
Coincidences of signals from the scintillation counters located near the focus F 6were
used as a trigger. Along with the secondary protons, the equipment detected the deuterons
that experienced inelastic scattering. The detected particles were identified off line during
the processing of the saved data on the basis of the information on their time of flight
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