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1. chinaXiv:202102.00080 [pdf]

Development of X-ray spectrometer automatic adjustment system based on global optimization algorithm

Fei Zhan
Subjects: Physics >> Nuclear Physics

In high energy resolution X-ray spectroscopy beamlines of synchrotron radiation (SR) facilities and laboratory XAS/XES spectrometer, it is important to keep X-ray spectrometer operating in optimal conditions. The adjusting process is normally very time consuming due to the irregular light source beam point, and it is difficult to get global optimum. This study aims to develop an intelligent adjusting system based on global optimization algorithm for spectrometers on SR beamlines and on laboratory x-ray source. First of all, based on the two dimensional experimental data, automatic adjustment process was established. Then the automatic optimization was applied to adjust X-ray spectrometer practically, and upgraded iteratively. The online testing is carried out on a self-developed laboratory XAS spectrometer. Online tests results show that this automatic adjustment process converges to the optimal solution quickly, and the convergence time is about several dozens to hundreds steps, more efficient than manual optimization process. After automatic adjustment, we can get correct X-ray absorption spectrum based on the adjusted spectrometer.

submitted time 2021-02-25 Hits90Downloads41 Comment 0

2. chinaXiv:201807.00040 [pdf]


Subjects: Physics >> Nuclear Physics

本文分析讨论了加速器的百年历史, 从思想的萌芽、理论的突破与准备、技术的准备与储存、实验的成功、加速器的未来与展望等几个方面进行了论述。

submitted time 2018-07-10 Hits3140Downloads1716 Comment 1

3. chinaXiv:201806.00237 [pdf]

On the analytical solution of accelerating structure

Subjects: Physics >> Nuclear Physics

本文讨论了加速结构中的解析求解问题, 主要讨论了场和等效电路两种求解方法。

submitted time 2018-06-20 Hits10948Downloads1116 Comment 0

4. chinaXiv:201801.00003 [pdf]


Subjects: Physics >> Nuclear Physics


submitted time 2018-01-01 Hits1871Downloads949 Comment 0

5. chinaXiv:201711.02796 [pdf]

Progress of beam diagnosis system for EAST neutral beam injector.pdf

Subjects: Physics >> Nuclear Physics

Neutral beam injection has been recognized as one of the most effective means for plasma heating.According to the research plan of the EAST physics experiment, two sets of neutral beam injector were built and operational in 2014. The paper presents the development of beam diagnosis system for EAST neutral beam injector (NBI) and the latest experiment results obtained on the test-stand and EAST-NBI-1 and 2. The results show that the optimal divergence angle is (0.62°, 1.57°) and the full energy particle is up to 77%. They indicate that EAST NBI work properly and all targets reach or almost reach the design targets. All these lay a solid foundation for the achievement of high quality plasma heating for EAST.

submitted time 2017-11-27 Hits1975Downloads1009 Comment 0

6. chinaXiv:201711.02561 [pdf]

Analysis of beam optics for a high power ion source

Subjects: Physics >> Nuclear Physics

The high power ion source is the key parts of neutral beam injector. Generally speaking, the beam power should matching the extraction voltage for a given accelerator. In order to get higher beam power with lower beam extraction voltage, the beam optics of accelerator was analyzed based on the structure of EAST-NBI tetrode accelerator. The beam optics of a tetrode accelerator and a new designed three-electrode accelerator was analyzed with beam energy of 50 keV. The results shown that, the two types of accelerator can get high beam perveance (4.6μp) with lower beam divergence angle compare to the EAST-NBI accelerator (2.8μp). And the tetrode accelerator can gets lower beam divergence angle compare to the three-electrode accelerator, but the electric field between two electrode is much higher than three-electrode accelerator. The results can help for the ion source design of high power ion source.

submitted time 2017-11-24 Hits1720Downloads876 Comment 0

7. chinaXiv:201703.00011 [pdf]

Calorimetric Power Measurements in the EAST ECRH System

Weiye Xu
Subjects: Physics >> Nuclear Physics

In this paper, the calorimetric power measurement method for electron cyclotron resonance heating system on EAST are presented. This method requires measurement of the water flow through the cooling circuits and the input and output water temperatures in each cooling circuit. Usually, the inlet water temperature is controlled to be stable to get more accurate results. The influence of the inlet water temperature change on the measurement results is analyzed for the first time in this paper. A novel temperature calibration method is proposed also. This kind of calibration method is accurate and effective, and can be easily implemented.

submitted time 2017-08-28 Hits3302Downloads1559 Comment 0

8. chinaXiv:201708.00282 [pdf]

The relativistic continuum Hartree-Bogoliubov description of charge-changing cross section for C, N, O and F isotopes

S.Q. Zhang; J. Meng; S.-G. Zhou; J.Y. Zeng
Subjects: Physics >> Nuclear Physics

The ground state properties including radii, density distribution and one neutron separation energy for C, N, O and F isotopes up to the neutron drip line are systematically studied by the fully self-consistent microscopic Relativistic Continuum Hartree-Bogoliubov (RCHB) theory. With the proton density distribution thus obtained, the charge-changing cross sections for C, N, O and F isotopes are calculated using the Glauber model. Good agreement with the data has been achieved. The charge changing cross sections change only slightly with the neutron number except for proton-rich nuclei. Similar trends of variations of proton radii and of charge changing cross sections for each isotope chain is observed which implies that the proton density plays important role in determining the charge-changing cross sections.

submitted time 2017-08-22 Hits1999Downloads1073 Comment 0

9. chinaXiv:201708.00281 [pdf]

Isospin and Z1/3 Dependence of the Nuclear Charge Radii

S.Q. Zhang; J. Meng; S.-G. Zhou; J.Y. Zeng
Subjects: Physics >> Nuclear Physics

Based on the systematic investigation of the data available for A ≥ 40, a Z1/3 dependence for the nuclear charge radii is shown to be superior to the generally accepted A1/3 law. A delicate scattering of data around Rc/Z1/3 is infered as owing to the isospin effect and a linear dependence of Rc/Z1/3 on N/Z ( or (N ? Z)/2 ) is found. This inference is well supported by the microscopic Relativistic Continuum Hartree-Bogoliubov (RCHB) calculation conducted for the proton magic Ca, Ni, Zr, Sn and Pb isotopes including the exotic nuclei close to the neutron drip line. With the linear isospin dependence provided by the data and RCHB theory, a new isospin dependent Z1/3 formula for the nuclear charge radii is proposed.

submitted time 2017-08-22 Hits1772Downloads954 Comment 0

10. chinaXiv:201708.00280 [pdf]

Pseudospin symmetry and its approximation in real nuclei

T.S. Chen; H.F. Lu; J. Meng; and S.-G. Zhou
Subjects: Physics >> Nuclear Physics

The origin of pseudospin symmetry and its broken in real nuclei are discussed in the relativistic mean field theory. In the exact pseudospin symmetry, even the usual intruder orbits have degenerate partners. In real nuclei, pseudospin symme- try is approximate, and the partners of the usual intruder orbits will disappear. The difference is mainly due to the pseudo spin-orbit potential and the transition between them is discussed in details. The contribution of pseudospin-orbit potential for intruder orbits is quite large, compared with that for pseudospin doublets. The disappearance of the pseu- dospin partner for the intruder orbit can be understood from the properties of its wave function.

submitted time 2017-08-22 Hits1713Downloads976 Comment 0

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