Determination of internal-target thickness and experimental luminosity from beam energy loss at HIRFL-CSRe

The target thickness for nitrogen was determined from the beam energy loss in HIRFL-CSRe during the experimental study of the K-REC process in 197 MeV/u Xe54+-N-2 collisions. Furthermore, the corresponding integrated luminosity of (1.15 +/- 0.06) x 10(30) cm(-2) was obtained. As an independent check on the energy-loss method, we have also determined the integrated luminosity by measuring the produced X-rays from the K-REC process with a known differential cross section. The values of (1.12 +/- 0.06) x 10(30) and (1.09 +/- 0.06) x 10(30) cm(-2) were obtained by using two high-purity germanium (HPGe) detectors which were oriented at 90 degrees and 120 degrees with respect to the beam path, respectively. The consistent results confirmed the feasibility of the energy-loss method, which may have an important impact on future internal target experiments at HIRFL-CSRe.