An investigation of four-body nuclear systems: A measurement of the cross section and analyzing powers for d+d elastic and d+d → p+t at intermediate energies

Measurements of the deuteron cross section and vector and tensor analyzing powers (Ay and Ayy) in d + d elastic and d + d → p + t channels were performed at 130 and 180 MeV, using a polarized deuteron beam at the KVI in Groningen, the Netherlands. These measurements were done in order to provide a testing ground for the theoretical treatment of the initial deuteron entrance channel, which had previously overestimated total cross section measurements for d + d → 4He+pi0 (CSB Experiment, 2002), and is based on a Neumann series expansion of the AGS equations. Additional measurements were also made of the d + p elastic cross section and analyzing powers at 130 and 180 MeV for use as a benchmark. Data was taken using the BBS (Big Bite Spectrometer), and beam polarization was monitored using the IBP (In Beam Polarimeter) at the KVI; analysis was performed using software written at IUCF. This measurement of the d+p elastic cross section and analyzing powers compares favorably with similar d+p elastic measurements taken previously (ranging from Ed=56.380 MeV). Comparison of all d + p elastic cross section data as a function of momentum transfer shows a clear energy independent scaling region; the KVI/IUCF d+p cross section data is consistent with this feature. Furthermore, a similar comparison of our d + d elastic data with previous measurements (ranging from E d=56.232 MeV) shows similar features, and again suggests that our data is consistent with other measurements. Agreement of theory with d + d data is best at energies above 200 MeV, where it qualitatively describes their general features, however agreement is lost as the energy goes down to 180 MeV and especially 130 MeV.