NEUTRON YIELDS FROM ALPHA-PARTICLE BOMBARDMENT

Thick-target ( alpha ,n) neutron yields have been measured for **6**,**7**,**N**A**TLi, **9Be, **1**0**,**1**1**,**N**A**TB, Pb**1**9F//2 and Zn**1**9F//2, **N**A**TMg, **2**7Al, **N**A**TSi, and **2**8Si**N**A**TO//2. From the Pb**1**9F//2 and Zn**1**9F//2 data, the authors have extracted the neutron yield that would result form the ( alpha ,n) reaction on a thick target of pure fluorine. Using the **2**8Si**N**A**TO//2 data, they have extracted the yield that would result from the ( alpha ,n) reaction on a thick target of pure **N**A**TO//2 and the **N**A**TO( alpha ,n) cross section at alpha-particle energies above those for which measurements previously existed. In addition, they have remeasured the thin-target oxygen cross section to obtain a correction to the previously measured values. Thick-traget yields are calculated from the cross-section values for carbon and oxygen and are compared to the experimental thick-target data. Thick-target yields for **2**3**8U**N**A**TO//2 and for **2**3**8U**N**A**TC are calculated from the thin-target cross sections. Results are compared to existing experiment and calculations.