Measurement of gas bremsstrahlung at the SPring-8 insertion device beamline using PWO scintillator
Measurement of gas bremsstrahlung at the SPring-8 insertion device beamline using PWO scintillator
复制标题
使用 PWO 闪烁体测量 SPring-8 插入装置光束线上的气体轫致辐射
DOI：
10.1016/s0168-9002(00)00346-6
复制
发表时间：
2000
影响因子：
1.4
通讯作者：
H. Yoshida
中科院分区：
文献类型：
--
作者：
Y. Asano;T. Matsumura;R. Chiba;T. Hashimoto;A. Miura;H. Shimizu;Y. Tajima;H. Yoshida
利用新型闪烁体PWO（PbWO 4）在SPring-8的插入装置光束线上测量了储存环真空室中储存电子与剩余气体分子相互作用产生的气体韧致辐射。对韧致辐射光子的能量分辨率达到铅玻璃的3倍。在BL 11 XU（高电子感应加速器功能束线）和BL 46 XU（低电子感应加速器功能束线）两条束线上进行了与存储电子束特性有关的测量。气体韧致辐射被测量为狭缝孔径大小的函数，显示出对存储电子束的条件以及束流和真空压力的明显依赖性。孔径尺寸依赖性的测量值与使用Monte Carlo程序EGS 4的计算值进行了比较，显示出相当好的一致性。气体韧致辐射的总功率估计为25.8±0.8nW/10− 8 Pa/mA，对应的等效剂量率计算为：对于BL 11 XU，0.023cm刻痕半径为15.8nSv/s/10− 8 Pa/mA;对于BL 46 XU，9.22nSv/s/10− 8 Pa/mA。在忽略离SPring-8直线段中心40米处的储存束流条件的情况下，还进行了计算，得到25.9nSV/s/10− 8 Pa/mA。
Gas bremsstrahlung, generated by the interaction of stored electrons with residual gas molecules in a storage ring vacuum chamber, was measured at the insertion device beamlines of SPring-8 by using a new-type scintillator PWO (PbWO4). The fine energy resolution for the bremsstrahlung photons was obtained, which is about three times as good as that of lead glass. The measurements were made at the two beamlines, BL11XU (high-betatron function beamline) and BL46XU (low-betatron function beamline), in relation to the characteristics of the stored electron beam. The gas bremsstrahlung was measured as a function of the aperture size of the slits, showing the apparent dependence on the conditions of the stored electron beam, as well as the beam current and the vacuum pressure. The measurements of the aperture size dependency were compared with the calculations by using the Monte Carlo code EGS4, to show a fairly good agreement. The total power of the gas bremsstrahlung was estimated as 25.8±0.8nW/10−8Pa/mA and the corresponding equivalent dose rates for a scoring radius of 0.023cm were calculated to be 15.8nSv/s/10−8Pa/mA for BL11XU, 9.22nSv/s/10−8Pa/mA for BL46XU. Calculations were also made to obtain 25.9nSV/s/10−8Pa/mA neglecting the stored beam conditions at 40m from the center of the straight section of SPring-8.