The neutron total cross section of a single crystal of Si was studied over the energy range 0.003 eV to 50 eV at the Weapons Neutron Research Facility (WNR). The neutron energies were determined by time of flight. The 28.77 cm long Si sample was held at three temperatures, 296K, 77K, and 20°K. The 21°K temperature was obtained by filling an encircling cryostat with liquid H2. The region of greatest interest is below 1 eV where Bragg scattering from the perfect crystal is small and where thermal diffuse scattering can be reduced by cooling the Si. Near 0.05 eV the cross section dips to less than 1/5 its value at energies greater than 1 eV. This feature has allowed single crystals of Si to be used very successfully as thermal neutron band pass filters. Data at 296K and 77°K agree with previous measurements. Very little structure caused by Bragg scattering is observed. Measured cross sections for 21°K are somewhat below the 77°K data but not enough lower to justify cooling a Si filter to 21°K to dramatically improve its transmission.

Neutron transmission through natural silicon samples has been measured for neutron energies between 5 eV and 730 keV. The Oak Ridge Electron Linear Accelerator (ORELA) was used to provide the neutrons. The 80-m flight path with a 6Li glass detector was used for the low energy measurement, and the 200-m flight path with a NE-110 detector was used for the higher energy measurements. The 1,488 resulting values are tabulated and compared with the current ENDF/B-IV evaluation.

The neutron total cross sections of several single crystals (Si, Cu, sapphire), several polycrystalline samples (Cu, Fe, Be, C, Bi, Ta), and a fine-powder copper sample have been measured from 0.002 to 5 eV. The Cu powder and polycrystalline Fe, Be and C data exhibit the expected abrupt changes in cross section. The cross section of the single crystal of Si is smooth with only small broad fluctuations. The data on two single Cu crystals, the sapphire crystal, cast Bi, and rolled samples of Ta and Cu have many narrow peaks approx. 10−3 eV wide. High resolution (0.3%) transmission measurements were made on the 1.057-eV resonance in 24°Pu and the 0.433-eV resonance in 18°Ta, both at room and low temperatures to study the effects of crystal binding. Although the changes in Doppler broadening with temperature were apparent, no asymmetries due to a recoilless contribution were observed.

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This second open access volume of the handbook series deals with detectors, large experimental facilities and data handling, both for accelerator and non-accelerator based experiments. It also covers applications in medicine and life sciences. A joint CERN-Springer initiative, the "Particle Physics Reference Library" provides revised and updated contributions based on previously published material in the well-known Landolt-Boernstein series on particle physics, accelerators and detectors (volumes 21A, B1,B2,C), which took stock of the field approximately one decade ago. Central to this new initiative is publication under full open access