Yangmei Fan

Implementation of a quantum algorithm to solve the Bernstein-Vazirani parity problem without entanglement on an ensemble quantum computer

Bernstein and Varizani have given the first quantum algorithm to solve parity problem in which a strong violation of the classical imformation theoritic bound comes about. In this paper, we refine this algorithm with fewer resource and implement a two qubits algorithm in a single query on an ensemble quantum computer for the first time.

Proton emission in reaction of 14.6-MeV neutrons with natural iron

The energy spectra and angular distributions of proton emission in a reaction of {sup nat}Fe(n,xp) at a neutron energy of 14.6 MeV are measured by the University of Science and Technology of China multitelescope system. The double-differential cross sections of 16 reaction angles from 25 to 164.5 deg are obtained in this measurement. The statistical errors are reduced largely because of the thick target used. The angular distributions show a slightly energy-dependent forward-backward asymmetry. The angle-integrated proton spectrum is compared with theoretical calculations and other results. The total proton-emission cross section is in fair agreement with the prediction and evaluation.

The 93Nb(n,xp) Reaction at En = 14.6 MeV

The energy spectra and angular distributions of the proton emission from the 93 Nb(n,xp) reaction are measured by means of the multitelescope system at the University of Science and Technology of China. The total proton production cross sections are in fair agreement with the results obtained by other groups. The energy spectrum is explained well by the sum of the spectra calculated on the basis of the pre-equilibrium and Hauser-Feshbach theories. There are deviations from a previous measurement of the high-energy end of the angle-integrated proton spectrum. The angular distribution, which shows a strongly energy-dependent forward-backward asymmetry, is in fair agreement with the Kalbach-Mann phenomenological model

Development of a pulse shape discrimination circuit

Abstract A pulse shape discrimination circuit was designed and used in an experiment measuring double-differential cross sections of (n, charged particle) reaction; to identify p, α and γ. The performance of the circuit was tested. With this circuit, excellent identification of p, α and γ was obtained.

The sputtering of radioactive recoil nuclides induced by fast neutron

The sputtering of radioactive recoil nuclides in nonelastic reactions induced by 14.9 MeV neutrons has been studied by both the theoretical calculation and the experimental measurement. The sputtering yields of recoil nuclides have been calculated for nonelastic neutron reaction based on the nuclear reaction dynamic and sputtering theory. Systematics of reduced sputtering yields depending on the mass number of recoil nuclides have been found for (n,2n), (n,p), (n,α) and (n,np) reactions. These systematics have also been demonstrated in the experimental measurement. Based on the differences of the calculating results and experimental ones, a universal revised calculating formula is presented for predicting the reduced sputtering yields induced by fast neutrons.

Reduced sputtering yields induced by fast neutrons

The reduced sputtering yield (YnR) of materials induced by fast neutron is presented. Based on the experimental YnR results for (n, 2n), (n, p), (n, α) and (n, np) reactions, the value of YnR for (n, non-elastic) reaction is deduced by using data of cross sections in JENDL-3.2 and ENDF/B-VI. The value of YnR for (n, n) reaction is predicted by relation between YnR and the mean projected ranges of recoil nuclides. Combining both YnR for (n, n) and (n, non-elastic) reactions, the total YnR is obtained. Systematics of YnR for (n, non-elastic), (n, n) and (n, total) reactions have been demonstrated.

Radioactivity Sputtered from Cooling-Pipe Materials into Coolant in the ITER Cooling System

Abstract The radioactivity induced by D-T neutron sputtering from piping materials to the coolant is described. The sputtering yields were calculated based on the systematics for (n,p), (n,α), (n,2n), and (n,np) reactions. Four candidate piping materials of AISI Types 316L and 304 stainless steel, Incoloy 800, and V-4 Cr-4 Ti alloy were investigated to estimate their radioactivity sputtered to the coolant. The investigation shows that radioactivity of ~1500 to 2000 Ci sputtered into the coolant at 1000-s plasma burn time of ITER, and after 1-day cooling, a few curies of gamma activity remain in the coolant, which will accumulate in the heat exchanger.

Measurement of backward sputtering yields induced by fast neutrons

This paper presents experimental methods and results of measuring backward sputtering induced by fast neutrons. Backward sputtering yields of 10 materials Mg, Al, Sc, V, Fe, Co, Cu, Zr, Au and type 316 stainless steel have been measured and compared with forward sputtering yields. The typical value of backward sputtering yield is about 10 ˇ8 ‐ 10 ˇ10 atoms per neutron, which is approximately 1‐2 orders smaller than that of forward sputtering. The present results have been compared with other experimental results and have been explained using sputtering theories. ” 2000 Elsevier Science B.V. All rights reserved.

Proton Emission Cross Sections for Bombardment of Stainless Steel by 14.6-MeV Neutrons

Proton emissions from the reaction of neutrons with stainless steel at a 14.6-MeV neutron energy are measured using a multitelescope system. A 1Cr18Ni9Ti (Type 321) stainless steel is used. The double-differential cross sections (DDCS) of 16 reaction angles from 25 to 165 deg are obtained in this measurement. The energy spectra and the angular distributions of proton emissions are obtained from the DDCS. The angular distributions show a slightly energy-dependent forward-backward asymmetry. The total proton emission cross section is 229 ± 16 mb for a proton energy >2 MeV.

Particle identification in the measurement of differential (n,χ) cross sections

Abstract An electronics system for five-parameter data collection was used for measuring double-differential (n,χ) cross sections in a multitelescope system. The charged particles have been identified by using energy loss ΔE spectrum, pulse-shape discrimination (PSD) spectrum, and their combination E - ΔE , E -PSD and ΔE -PSD spectra. Three two-dimensional spectra are combined to identify proton and alpha particles in the experiment of measuring double-differential nat Ni (n,χ) cross sections. Excellent particle identification has been obtained.