arXiv subjects

A. A. Derevschikov

Publications and source records attributed to A. A. Derevschikov.

167 records · Page 10Linked to original sources

arXiv2005

Correlation of Beam Electron and LED Signal Losses under Irradiation and Long-term Recovery of Lead Tungstate Crystals

Radiation damage in lead tungstate crystals reduces their transparency. The calibration that relates the amount of light detected in such crystals to incident energy of photons or electrons is of paramount importance to maintaining the energy resolution the detection system. We report on tests of lead tungstate crystals, read out by photomultiplier tubes, exposed to irradiation by monoenergetic electron or pion beams. The beam electrons themselves were used to measure the scintillation light output, and a blue light emitting diode (LED) was used to track variations of crystals transparency. We report on the correlation of the LED measurement with radiation damage by the beams and also show that it can accurately monitor the crystals recovery from such damage.

physics.ins-det↗

arXiv2005

Single spin asymmetry measurements for $π^0$ inclusive productions in $p+p_{\uparrow} \to π^0 + X$ and $π^-+\p_{\uparrow}\to π^0+X$ reactions at 70 and 40 GeV respectively

The inclusive $π^0$ asymmetries were measured in reactions $p+p\uparrow \to π^0+X$ and $π^-+p\uparrow \to π^0+X$ at 70 and 40 GeV/c respectively. The measurements were made at the central region (for the first reaction) and asymmetry is compatible with zero in the entire measured $p_T$ region. For the second reaction the asymmetry is zero for small $x_F$ region ($-0.4<x_F<-0.1, 0.5<p_T(GeV/c) <1.5$) and increases with growth of $\mid x_F\mid$. Averaged over the interval $-0.8<x_F<-0.4, 1<p_T(GeV/c)<2$ the asymmetry was $-(13.8\pm 3.8)%$.

hep-ex↗

arXiv2005

$A_N$ at small negative values of $\xf$ in the reaction $p+p(pol) \to π^0+X$ at 70 GeV and universal threshold in inclusive pion production

The talk continues the series of Single Spin Asymmetry (SSA) $π^0$ inclusive measurements carried out at Protvino 70 GeV accelerator. The asymmetry in the polarized target fragmentation region grows up in absolute value with $\xf$ decreasing and equals to $(-16 \pm 5)%$ at $-0.4<\xf<-0.25$. The result of the current experiment is in agreement with the universal threshold in pion asymmetries.

hep-ex↗

arXiv2004

Study of Possible Scintillation Mechanism Damage in PbWO4 Crystals After Pion Irradiation

We employed two independent methods to study possible damage to the scintillation mechanism in lead tungstate crystals due to irradiation by a 34 GeV pion beam. First, 10 crystals were irradiated simultaneously over 30 hours by a narrow beam, so that only a small region of each crystal was affected. We studied the effect of the irradiation on the light output non-uniformity. If a localized degradation was observed, it would indicate damage to the scintillation mechanism. Secondly, we detected light output using two phototubes attached to sides of a crystal. Since these phototubes detect scintillation light only from a small localized region, the effect of transmission loss should be minimal. We did not see any statistically significant evidence for scintillation mechanism damage with either method. The effect is consistent with zero, and the upper limit is 0.5% at 95% C.L.

physics.ins-det↗

arXiv2002

Development of a Momentum Determined Electron Beam in the 1 -45 GeV Range

A beam line for electrons with energies in the range of 1 to 45 GeV, low contamination of hadrons and muons and high intensity up to 10^6 per accelerator spill at 27 GeV was setup at U70 accelerator in Protvino, Russia. A beam tagging system based on drift chambers with 160 micron resolution was able to measure relative electron beam momentum precisely. The resolution sigma_p p was 0.13% at 45 GeV where multiple scattering is negligible. This test beam setup provided the possibility to study properties of lead tungstate crystals (PbWO_4) for the BTeV experiment at Fermilab.

hep-ex↗