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In a \((\vec d,\vec n)\) reaction, the polarization transfer coefficient K y y′ measures the fraction of vector polarization of the incident deuteron transferred to the outgoing neutron. For the D\((\vec d,\vec n)\) 3He reaction at θ = 0°, it is known that this parameter remains at nearly 90% of a simple stripping model value of 2/3 over the energy range extending from 4 to 15 MeV1,2). In order to investigate the systematics of the same polarization transfer coefficient for heavier nuclei, we have made similar measurements for targets of 12C, 14N, 160, and 28Si. In this paper we report our results for the reactions \(^{16}0{(\vec d,{\vec n_0} + {\vec n_1})^{17}}F,{^{28}}Si{(\vec d,{\vec n_o})^{29}}p,an{d^{14}}N{(\vec d,\vec n)^{15}}0\) (leading to states around 5 MeV in excitation of 150.) In each of these reactions, it is believed that the dominant contribution to the measured neutron groups is lp = 0.

The magnitude of the polarization observed in neutron-proton scattering for En < 20 MeV is known to be less than a few percent and has been difficult to measure accurately. The usual experimental arrangement used to obtain n-p polarization data involves organic scintillators as scatterers; consequently, the systematic accuracy depends on the amount of multiple scattering from carbon and hydrogen in the scatterer. Although n-12C scattering yields large polarization in the relevant energy region1), the background polarization has been either assumed to be zero or, in one instance at 23.1 MeV2), demonstrated to be small by measurements with two scatteres of different size.

Differences between Py and Ay for mirror reactions may be capable of yielding information about isospin violation terms in nuclear interactions [see ref.1)]. Thus far such studies have been reported only for T(p,n)3He and 7Li(p,n)7Be. In the first case, large differences were observed; in the second, considerable similarities were reported, particularly at 3 MeV, the highest energy for which Ay was measured. In order to extend the comparison of these two observables to heavier targets, the 9Be(p,n)9B and 15N(p,n)15O) reactions have been investigated at our laboratory. This report gives the preliminary results of the 9Be(p,n)9B experiment, which obtained Ay data in 10° steps from 20° to 100° at 8.1 and 9.1 MeV and Py data at 8.1 MeV for the same angles.

Recent advances in the field of few-nucleon theory have made it possible to calculate accurate representations of cross section and polarization data for the mass-three system. Although most of the theoretical work has dealt with two-particle final-state reactions, detailed calculations of cross sections for the N-D break-up channel are beginning to appearl). As a benchmark for future theoretical calculations which include spin-dependent forces, a determination of the polarization transfer coefficient K y y′ for the D(\(\vec p\),\(\vec n\))2p reaction at θ = 0° has been made at five proton energies from 10.5 to 15.0 MeV.

Although the (p, n) reaction between mirror nuclei has long been used to explore the effective neutron-proton interactionl,2), special attention has recently been given to differences between the polarization P and analyzing power A3,4). Following Conzett4), we consider a measurement of P in the reaction \( B\left( {p,\vec n} \right)B' \), for which invariance under time reversal I gives $$ B\left( {p,\vec n} \right)B' = B'\left( {\vec n,p} \right)B\left( {P = {A_I}} \right). $$

In the energy range from threshold to 12 MeV, the 12C(d,n)13N reaction and the mirror reaction 12C(d,p)13C exhibit considerable structure in the forward angle cross section excitation function. This structure must be due to compound nucleus effects in the interaction, so it is not surprising that DWBA calculations have never been able to describe suitably the angular dependence of the differential cross section, the polarization, and the asymmetry. In addition, the 12C(d,n)13N reaction has the interesting feature that although the magnitude of the differential cross section changes appreciably with energy in the region of the peaks in the excitation function, its angular dependence, or pattern, is not grossly altered. This observation, along with the fact that the reaction cross section exhibits an lp = 1 stripping shape, suggests that the effect of the resonances is primarily to enhance the probability that the stripping reaction should take place.