Radiochemical Study on Photonuclear Reactions at Intermediate Energies

以100 MeV或更小的步长，在端点能量（E_0）从40到1000 MeV的^7Li到^<207>Bi范围内，对轫致辐射诱导的光子、光裂和光裂进行了系统的放射化学研究。(1) ^ 7的收益率,^ < 11 > C ^ < 27 > Mg, ^ < 41 > Ar, ^ < 59 >铁、^ < 87 > Kr, ^ < 88 > Rb, ^ < 103 >俄文,^ < 133 > Xe ^英航和^ < 139 > < 181 >的高频(γ,π^ < <加减> >)的反应和^ < 59-x >镍(x = 2, 3) ^ < 127 - x > Xe (x = 0 - 6) ^ < 133 - x > Ba (x = 0 - 9) ^ < 139 - x > Ce (x =主/从(γ,π^ xn反应得到李从^ 7 ^ < 11 > B, ^ < 27日>,^ < 41 > K, ^ < 59 >有限公司^ < 87 > Rb, ^ < 88 > Sr, ^ < 103 > Rh, ^ < 127 >我^ < 133 > Cs, ^ < 139 >洛杉矶和^ < 181 >助教。对二次反应校正后的测量产率进行了单色能量k每光子的截面展开。推导了激发曲线的（3,3）共振特征，并结合全光吸收截面和光子诱导级联分析（PICA）计算，讨论了激发曲线关于k（和E_0）、A_t和x的系统特征。结果是符合我们之前发现^ 51 < > V(γ,π^ +)^ 51 < > Ti, ^ 51 > < V(γ,π^ xn) ^ < 51-x > Cr (x = 0、2、3)^ < 89 > Y(γ,π^ xn) ^ < 89 - x >锆(x = 0 - 3)、^ < 197 >非盟(γ,π^ xn) ^ < 197 - x > Hg (x =鹿)和^ < 209 > Bi(γ,π^ xn) ^ < 209 - x > Po (x = 2 - 7日)。(2)从阈值到1000 MeV，测量了21 ~ 47种产品的产率，每种产品的产率为5 ~ 10个元素，从^<51>V, ^<59>Co, ^<89>Y, ^<127>I, ^<133>Cs, ^<139>La, ^<176>Lu, ^<197>Au和^<209>Bi。在对前体衰变进行校正后，研究了同位素、等压分布和电荷分布及其E_0和A_t的依赖关系，并参考强子分裂的Rudstam公式提出了新的产物形成经验表达式。对韧致裂进行了PICA计算，发现不能再现观察到的产量，特别是对于中至重目标。(3)虽然^<35.37>Cl、^<63.67>Cu和^<89>Y的^<22.24>Na产率可以用散裂解释，但这些靶的^<7.10>Be产率很高，但与质量有关。少

A systematic radiochemical study on bremsstrahlung-induced photopion, photospallation and photofragmentation was performed on targets ranging from ^7Li to ^<207>Bi at end-point energies (E_0) from 40 to 1000 MeV in steps of 100 MeV or less.(1) The yields of ^7Be, ^<11>C, ^<27>Mg, ^<41>Ar, ^<59>Fe, ^<87>Kr, ^<88>Rb, ^<103>Ru, ^<133>Xe, ^<139>Ba and ^<181>Hf from (gamma, pi^<<plus-minus>>) reaction and of ^<59-x>Ni(x=2,3), ^<127-x>Xe(x=0-6), ^<133-x>Ba(x=0-9), ^<139-x>Ce (x=0-8) from (gamma, pi ^-xn reactions were obtained from ^7Li, ^<11>B, ^<27>Al, ^<41>K, ^<59>Co, ^<87>Rb, ^<88>Sr, ^<103>Rh, ^<127>I, ^<133>Cs, ^<139>La and ^<181>Ta. Unfolding into cross sections per photon of monochromatic energy k was performed on the measured yields after correction for secondary reactions. Excitation curves were characteristic of (3,3) resonance, and their systematic features with respect of k (and E_0), A_t and x were derived and discussed with references of total photoabsorption cross sections an … More d also of PICA (photon-induced cascade analysis) calculations. Results were consistent with our previous findings from ^<51>V (gamma, pi^+) ^<51>Ti, ^<51>V (gamma, pi^-xn) ^<51-x>Cr (x=0,2,3), ^<89>Y (gamma, pi^-xn) ^<89-x>Zr (x=0-3), ^<197>Au (gamma, pi^-xn) ^<197-x>Hg (x=0-7) and ^<209>Bi (gamma, pi^-xn) ^<209-x>Po (x=2-7).(2) The measured yields of 21 to 47 products ranging in 5-10 elements each from the targets of ^<51>V, ^<59>Co, ^<89>Y, ^<127>I, ^<133>Cs, ^<139>La, ^<176>Lu, ^<197>Au and ^<209>Bi were measured as a function of E_0 from thresholds to 1000 MeV. After correction for precursor-decays, isotopic, isobaric and charge distributions and their E_0 and A_t dependences were investigated and a new empirical expression for the product formations were proposed with reference to Rudstam formula for hadron spallation. PICA calculations for bremsstrahlung spallation were performed and found not to reproduce the observed yields especially for medium to heavy targets.(3) While the ^<22.24>Na yields from ^<35.37>Cl, ^<63.67>Cu and ^<89>Y were explained by spallation, photofragmentaion was evidenced with high but mass dependent yields of ^<7.10>Be from these targets. Less