Properties of 23Na implanted targets

Absolute determination of theNa22(p,γ)Sallaska1, Wrede2, Garcı́a3 et al. 2011Phys. Rev. CSelf Cite255340View full textAdd to dashboardCite

“…As target degradation can be quite problematic, we carried out a program [27] to determine the ideal combination of implantation energy, substrate, and possible protective layer by bombarding 23 Na targets implanted under similar conditions. Using the conclusions of Ref.…”

“…Using the conclusions of Ref. [27], two additional ∼ 300 µCi 22 Na targets, #3 and #4, were implanted with the same parameters but included a 20-nm protective layer of chromium, deposited by vacuum evaporation after implantation. A small rise in temperature of the target was observed during the evaporation; however, a survey of the apparatus showed no residual activity from diffusion of 22 Na out of the target.…”

“…5 shows this two-dimensional raster plot, obtained with a 5-mm diameter, 1.5-mm thick 27 Al disc embedded in the center of a copper backing. This "coin" target had the same OFHC copper substrate and diameter as our 22 Na targets.…”

“…We also conducted measurements on 27 Al targets in order to extract the normalized beam density, averaged over the 5-mm diameter area. Systematic errors were then explored with simulation and visual inspection of beam-related target coloration.…”

“…The measurements were performed at the Center for Experimental Nuclear Physics and Astrophysics of the University of Washington with ion-implanted 22 Na targets prepared at TRIUMF-ISAC. Thanks to evaporated protective layers [27], the targets exhibited little to no degradation over ∼ 20 C of bombardment. Using mainly the strengths and energies obtained in this work together with supplemental information from other work [24,28], we have re-evaluated the thermonuclear reaction rate of 22 Na(p, γ), and full hydrodynamic simulations have been performed to estimate the effect of the new rate on the flux of 22 Na from novae.…”