Development of crystal extraction studies at the IHEP accelerator
The crystal extraction of 10/sup 7/ proton/s at the BEC experimental facility is described. Detailed computer analysis is made to explain the basic experimental results. Future high-intensity efficient extraction using a short crystal is announced.
Crystal bending of the LHC beam for in situ calibration of ATLAS and CMS calorimeters
Abstract The physical possibility for bending the LHC protons and ions by a huge angle from 1° to 20° in the energy range of 0.45–7 TeV by means of a bent single crystal of silicon or germanium is studied. Such an application can be useful, e.g. for calibration of CMS or ATLAS calorimeters in situ by the LHC beam of precisely known energy. We show by simulations that this application would be feasible at the LHC, and report the experience of IHEP Protvino in bending 70 GeV protons by 9° (150 mrad) during 10 years of experiments in 1994–2004.
Effect of temperature on the solvated electron in 1-propanol
Abstract The technique of pulse radiolysis has been used to study the effect of temperature on the solvated electron in 1-propanol. The spectrum of the solvated electron has been measured in the range 140–298 K. The wavelength at maximum absorption, λ max , decreases with decreasing temperature (corresponding to an increase in the energy, E max ) but the spectral width at half height, ΔE 1 2 , changes little with temperature. At temperatures above ≈180 K, the formation of the solvated electron is complete at the end of the pulse and its spectrum shows no change in shape with time. Below ≈170 K, the absorption spectrum is time-dependent in both liquid and glassy phases, the changes being attributed to the solvation process. The reaction(s) leading to solvated electron formation following the pulse show an activation energy of 22±2 kJ mol − and the solvated electron decays with an activation energy of 20±2 kJ mol −1 . The yield of solvated electrons decreases continuously with decreasing temperature in the range 298-77 K and, at all temperatures studied, is less than the total ionization yield measured by scavenging techniques.