2 00 5 A luminosity monitor for the A 4 parity violation experiment at MAMI
نویسنده
چکیده
A water Cherenkov luminosity monitor system with associated electronics has been developed for the A4 parity violation experiment at MAMI. The detector system measures the luminosity of the hydrogen target hit by the MAMI electron beam and monitors the stability of the liquid hydrogen target. Both is required for the precise study of the count rate asymmetries in the scattering of longitudinally polarized electrons on unpolarized protons. Any helicity correlated fluctuation of the target density leads to false asymmetries. The performance of the luminosity monitor, investigated in about 2000 hours with electron beam, and the results of its application in the A4 experiment are presented.
منابع مشابه
From Polarized Bhabha Scattering Atthez'resonance
. . 111 The cross section for Bhabha scattering (e+e+ e+c-) with polarized electrons at the center of mass energy of the 2’ resonance has been measured with the SLD experiment at the Stanford Linear Accelerator Center during the 1992 and 1993 runs. The electroweak couplings of the electron are extracted. At small angles the measurement is done in the SLD Silicon/Tungsten Luminosity Monitor (LMS...
متن کاملVARIOUS IMPROVEMENTS TO OPERATE THE 1.5 GeV HDSM AT MAMI
During the last three years at the 1.5 GeV Harmonic Double Sided Microtron (HDSM, [1]) of MAMI a lot of improvements concerning the longitudinal operation of the accelerator were tested and installed. To monitor the rf-power dissipated in the accelerating sections, their cooling water flow and its temperature rise are now continuously logged. Phase calibration measurements of the linacs and the...
متن کاملElectroproduction of Hyperons
We present some estimates for the reaction ~ ep ! e 0 +. At small scattering angles, the diierential cross section is completely determined by the experimental data for the radiative decay + ! pp. For kinematical values typical of the proposed parity experiment at MAMI, we nd a suppression factor of about 5 10 ?15 as compared to elastic electron scattering. On the basis of conservative models f...
متن کاملTarget Density Fluctuation Monitoring in the HAPPEX Helium Parity Violation Experiment
Luminosity monitors were used to study density fluctuations in the cold helium-4 target of the HAPPEX-He parity violation experiment in Jefferson Lab Hall A. Helicity-correlated asymmetries were measured as beam current, beam raster size, target fan speed, and target density were varied. These studies were used to determine optimal running conditions and estimate the contribution of target dens...
متن کامل0 v 1 6 M ay 2 00 5 Observation of Parity Violation in the Ω − → Λ K − Decay
The α decay parameter in the process Ω − → ΛK − has been measured from a sample of 4.50 million unpolarized Ω − decays recorded by the HyperCP (E871) experiment at Fermilab and found to be [1.78±0.19(stat)±0.16(syst)]×10 −2. This is the first unambiguous evidence for a nonzero α decay parameter, and hence parity violation, in the Ω − → ΛK − decay.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2005