Measurement of cross sections for inelastic cold-neutron scattering in metals and polymers by the method of (n, γ) analysis

Arzumanov, Sergei S.; Bondarenko, L. N.; Geltenbort, P.; Морозов, В. И.; Panin, Yu. N.; Chernyavsky, S. M.

doi:10.1134/s1063778808110057

Cited by 2 publications

(2 citation statements)

References 3 publications

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“…The measurements were performed using a new method based on a combination of high-resolution γ spectrometry with total absorption of the neutron beam in the experimental target sample, which is a further elaboration of the neutron-radiation analysis [17].…”

Section: Measurement Of the Inelastic Scattering Of Very Cold And Ultmentioning

confidence: 99%

Neutron-capture therapy with ultra-cold neutrons

et al. 2010

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The status of neutron-capture therapy of malignant tumors and its problems -damage to healthy tissue as a result of neutron transport to the irradiation location and presence in the therapeutic beam of a background consisting of γ rays and fast neutrons -are presented. To solve these problems, the authors have proposed using ultracold neutrons with energy less than 10 -7 eV, whose unique capability is to undergo total reflection from the surface of a condensed substance at any angle of incidence. Numerous works have demonstrated that such neutrons can be transported along neutron guides. The cross section for inelastic scattering of neutrons by hydrogen-containing substances -water, ethyl alcohol, and biological tissue -has been measured in an IR-8 beam of ultracold and very cold neutrons. At temperature 200-300 K, the experimental data are in very good agreement with calculations, but as temperature decreases further a discrepancy appears, which could be due to the inaccuracy of the model spectra of the oscillations hydrogen-containing substances used in the calculations. The use of ultracold neutrons opens up new possibilities of neutron-capture therapy for treating malignant tumors localized in body cavities or organs.Radiation therapy is one of the main methods of treating cancer. Up to 70% of cancer patients need radiation therapy in one form or another.The methods of radiation therapy are developing along the lines of optimizing and creating new technologies characterized by selective destruction of tumor tissues and sparing radiation exposure of normal tissues in the body. A promising therapy meeting these requirements is neutron-capture therapy, characterized by high linear transfer of energy of heavy particles and, correspondingly, higher relative biological effectiveness than conventionally used forms of radiation.Neutron-capture therapy of malignant tumors is based on the absorption of neutrons by the stable boron isotope 10 B or gadolinium 157 Gd and release of substantial energy by the reaction products [1,2]. At the first stage a preparation containing, for example, 10 B, is introduced into the tumor. Then the tumor is irradiated with neutrons. When a 10 B nucleus absorbs a neutron, an α particle and a 7 Li ion, whose ranges in biological tissue are ~10 μm, are formed as a result of the reaction 10 B(n, α) 7 Li. An amount of energy equal to 2.3 MeV is released in a cancer cell; this destroys the cell. In a reaction with 157 Gd, high-energy photon and electron radiation (conversion and Auger electrons), are formed; this radiation is localized within 1-40 μm from the point of the reaction.Today nuclear reactors, accelerators, and generators are used in radiation therapy as sources of neutrons. In addition, the possibility of using sources based on 252 Cf is being investigated for contact neutron therapy. These sources of neutrons can be ranked on the basis of different grounds but only nuclear reactors and accelerators are the real competitors for mass use. They will make it possible to perform most o...

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Section: Measurement Of the Inelastic Scattering Of Very Cold And Ultmentioning

confidence: 99%

Neutron-capture therapy with ultra-cold neutrons

et al. 2010

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“…Therefore, it was originally assumed that the main contribution to the 𝜂 𝑡𝑜𝑡 value comes from inelastic scattering of UCNs into the range of thermal energies; the scattering occurs on collective vibrations of atoms located in the near-surface oil layer of ~30 nm deep, available for UCNs [7]. However, the calculated value of the total UCN loss coefficient obtained from experiments on the transmission of neutrons with a velocity of 9 m/s through the bulk layer of oil turned out to be 3 times lower than the value obtained from UCN storage experiments [12][13]. The difference can probably be explained by additional oscillation modes of the atoms, which appear exclusively on the surface of Fomblin oil.…”

Section: Introductionmentioning

confidence: 99%

Temperature dependence of the probability of “small heating” and total losses of UCNs on the surface of Fomblin oils of different molecular mass

et al. 2019

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We measured the temperature dependence of the probability of small heating and total losses of UCNs on the PFPE Fomblin Y surface with various molecular mass ̅ (2800, 3300, 6500 аmu) in the temperature range of 100-300 К. The probability of small heating sharply decreases with increasing ̅ and decreasing temperature. The probability of total loss weakly decreases with decreasing temperature and takes the minimum value at ̅ = 3300 аmu. As this oil provides a homogeneous surface with minimal probabilities of small heating and total losses of UCNs, it is the preferred candidate for experiments on measuring the neutron lifetime.

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Measurement of cross sections for inelastic cold-neutron scattering in metals and polymers by the method of (n, γ) analysis

Cited by 2 publications

References 3 publications

Neutron-capture therapy with ultra-cold neutrons

Neutron-capture therapy with ultra-cold neutrons

Temperature dependence of the probability of “small heating” and total losses of UCNs on the surface of Fomblin oils of different molecular mass

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