Development of Ion Detector Based on Low-Pressure Time Projection Chamber for Accelerator Mass Spectrometry

Physics of Atomic Nuclei - A new ion identification method for accelerator mass spectrometry on the basis of measuring ion track ranges is proposed. A low pressure time projection chamber (TPC)...     

Pair production of pions with symmetric momenta in the range 0.5⩽pT⩽2.0 GeV/c In 70 GeV p-p collisions

The invariant cross-section slope of the pp→π⁺π^?+X process as a function of p_T is found to have a break near 1 GeV/c. Fitting the cross section by a sum of two exponents gives the values of powers (12.3±0.9)(GeV/c)^?1 and (8.7±0.6)(GeV/c)^?1. The experimental points at p_T?1 GeV/c are significantly higher than predictions based on hard scattering models such as QCD and CIM.     

HighP ∧ hadron production off nuclei at 70 GeV

Invariant cross sections for hadron production (π^±,K ^± ,p and \(\bar p\) ) by protons off C, Al, Cu, Sn and Pb nuclei have been measured at 70 GeV for theP _∧ range from 1 up to 4.65 GeV/c. TheA-dependence of the invariant cross section is not described by the exponentialA ^α(P _∧), which points to the presence of secondary hadron absorption in nuclei.     

Gaseous photodetectors with solid photocathodes

Remarkable properties of gas photodetectors make them attractive for application in high energy physics, astrophysics, and medical imaging. This review presents the results of research and development of gaseous photodetectors with solid photocathodes (GPDs). In particular, efficient photocathodes for the ultraviolet (mainly CsI) and the visible ranges, including photocathodes with protective dielectric nanofilms, are described. Some problems of the physics of gaseous photodetectors and photocathodes are considered: photoelectron backscattering in gas, photoemission amplification in an electric field, photoelectron transport through nanofilms, protective properties of nanofilms, and photon and ion feedback. A separate section is devoted to GPDs based on gas electron multipliers (GEMs), including sealed GPDs and cryogenic two-phase avalanche detectors with CsI photocathodes.