Coherent scattering cross sections of some lanthanides for 241Am and 137Cs gamma rays at low momentum transfer

Small angle scattering of 59.54 keV photons by elemental samples in the atomic number region 13 ≤ Z ≤ 82

“…These values have been listed in Table 1 along with the corresponding S-matrix values, s S . The procedure for the evaluation of s 1 , s 2 and model based J o u r n a l o f R a d i a t i o n R e s e a r c h a n d A p p l i e d S c i e n c e s 9 ( 2 0 1 6 ) 3 5 e4 0 theoretical scattering cross sections (s inc NRHF , s inc MFF and s S ) was similar to that detailed in an earlier work reported by the authors (Vinaykumar & Umesh, 2014). The experimental errors of 4%e5% were excepted to carry over to s 1 and s 2 also.…”

“…This may be attributed to the fact that, since the scattering of gamma rays in this region involves low momentum transfer to the struck electron, it is difficult to separate out the coherent scattering from the main peak particularly due to the severe limitations imposed by the finite resolution of the detector (This is the case even with high resolution detectors such as HPGe detector). For this purpose, a new experimental technique which could overcome this difficulty while measuring the scattering cross sections at small scattering angles was reported recently by the authors (Vinaykumar & Umesh, 2014). This method is simple and involves only the measurement of the scattered intensity superposed as a small addition to the direct transmitted beam by making use of a NaI(Tl) detector.…”

Effective atomic number of some sugars and amino acids for scattering of 241 Am and 137 Cs gamma rays at low momentum transfer

“…The details of the experimental procedure, calculation of the angle integrated Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/apradiso small angle scattering cross sections of the sample and the errors were identical to those in an earlier work reported by the authors recently (Vinaykumar and Umesh, 2014).…”

“…) and S x Z , ( ) values provided in the compiled non-relativistic Hartree-Fock data of Hubbell et al (1975) over the angular range (0-θ°) by the usual procedure (Vinaykumar and Umesh, 2014) by choosing intervals in steps of 0.02°over a given angular range. This was done for all the angular ranges of (0-4°), (0-6°), (0-8°) and (0-10°).…”

Coherent and Incoherent Scattering Cross Sections of Some Lead and Sodium Compounds at Angles below 10° for 241Am Gamma Rays

“…The possible source of errors was mainly due to counting statistics, nonuniformity of scatterer material, sample impurity, and photon dose buildup inside the scatterer. The detailed error calculations were published elsewhere [9].…”