Vol.27,

The zero degree calorimeter (ZDC) at RHIC-STAR was installed in the year 2000. After running for more than 10 years, the performance of the STAR-ZDC cannot maintain a proper status because of the radiation damage. The ZDC on RHIC-BRAHMS had been moved to STAR in 2011 after some tests. We present here the result of the tests as well as the physical performance of those ZDC modules between the 2011 to 2015 RHIC run. The excellent energy resolution of the ZDC in heavy ion collision provide a good candidate for future detecter development, such as the CSR experiment at CAS-Lanzhou facility.

406

Deformed even–even nuclei Barium isotopes with quadrupole–octupole deformations are investigated on the basis of a collective model. The model describes energy levels of the yrast band with alternating parity in the neutron-rich ^{140,142,144,146,148}Ba. The structure of the alternating parity bands is examined by odd-even (ΔI=1) staggering diagrams. An analytical method of the collective model is proposed for the calculation of E2 transition probabilities in alternating spectra of the nuclei ^{140,142,144,146}Ba.

534

A new material is prepared by impregnating the expanded graphite (EG) into ethanol solutions of metal acetate then drying and reducing it in H₂. It contains the EG and the nanoparticles of the magnetic Ni-Fe alloy for the electromagnetic shielding. Its morphology, phase structure, magnetic properties, and electromagnetic shielding effectiveness (SE) are investigated in our experiment. It shows that the morphology, the phase structure, and the magnetic property of the composite can be modified by altering the Ni content in the alloy nanoparticles. Interestingly, the SE can be enhanced to 54-70 dB at low frequencies (300 kHz-10 MHz) by dispersing the magnetic nanoparticles onto EG.

404

The fuel assembly is key structure in China Initiative Accelerator Driven System (CIADS), and the axial fitting clearance (AFC) for the fuel assembly design is an essential subject of study. In this paper, different methods are used to calculate critical stress in cylindrical shells. Because the thermal expansion of fuel assembly outer tube is larger than that of the cladding of fuel rod, enough space should be reserved between the upper end plug and upper seat slot. The collapse critical compressive stress of the cladding is obtained numerically through ANSYS simulation calculation. The AFC range between the fuel rod cladding and the end seat due to the displacement of thermal expansion is given by the theoretical formulas and ANSYS buckling analysis. These provide a reference for the AFC design of the reactor fuel assembly.

398

404

A Bonner Sphere Spectrometer (BSS) was developed for neutron diagnostic on HL_2A Tokamak. It contains eight polyethylene (PE) spheres embedded with SP9 ³He proportional counter. Before setting up on the Tokamak experimental hall, a verification experiment was arranged on a ²⁴¹Am-Be neutron source to test its spectrometry capability. The neutron response functions were calculated by Monte Carlo code Geant4 to simulate the real measurement environments. By least square method, the neutron spectrum was finally unfolded on log-domain from 0.1 eV to 11 MeV. It has a remarkable consistency to the ISO 8529-1 standard ²⁴¹Am-Be neutron spectrum. This shows that the BSS is effective and reliable for neutron spectrum determination.

386

Readout electronics is developed for a prototype spectrometer for in situ measurement of low energy ions of 30 eV/e–20 keV/e in the solar wind plasma. A low-noise preamplifier/discriminator (A111F) is employed for each channel to process the signal from micro-channel plate (MCP) detectors. A high voltage (HV) supply solution based on a HV module and a HV optocoupler is adopted to generate a fast sweeping HV and a fixed HV. Due to limitation of telemetry bandwidth in space communication, an algorithm is implemented in an FPGA (field programmable gate array) to compress the raw data. Test results show that the electronics achieves a 1MHz event rate and a large input dynamic range of 95 pC. A slew rate of 0.8 V/μs and an integral nonlinearity of 0.7-LSB for the sweeping HV, and a precision of less than 0.8% for the fixed HV are obtained. A vacuum beam test shows an energy resolution of 12% ±0.7% full-width at half-maximum (FWHM) is achieved and noise counts are less than 10/sec, indicating that the performance meets the physical requirement.

405

Digital pulse processing has developed rapidly during recent years. Moreover, it has been widely applied in many fields. In this study, we introduce a digital pulse processing method for 2πα and 2πβ emitter measurement. Our digital pulse processing method for 2πα and 2πβ emitter measurement is comprised of a field programmable gate array (FPGA) based acquisition card and a pulse height analysis routine. We established 2 channels (one for the α emitter and one for the β emitter) on an acquisition board using an analog to digital converter (ADC) with a 16-bit resolution at a speed of 100 million samples per second (MSPS). In this study, we used captured and stored data to analyze emission rate counts and spectrums. The method we established takes into account noise cancelation, dead time correction, background subtraction, and zero-energy extrapolation. We carefully designed control procedures in order to simplify pulse width fitting and threshold level setting. We transmitted data and commands through a universal serial bus (USB) between the acquisition board and the computer. The results of our tests prove that our method performs well in pulse reconstruction fidelity and amplitude measurement accuracy. Compared to the current standard method for measuring 2πα and 2πβ emission rates, our system demonstrates excellent precision in emission rate counting.

377

We report on our results about spontaneous chiral symmetry breaking for quark matter in the background of static and homogeneous parallel electric field, E, and magnetic field, B. A Nambu-Jona-Lasinio model is used to compute the dependence of the chiral condensate at finite temperature, E and B. We study the effect of this background on inverse catalysis of chiral symmetry breaking for E and B of the same order of magnitude. We also consider the effect of equilibration of chiral density, n₅, produced by axial anomaly on the critical temperature. The equilibration of n₅ allows for the introduction of the chiral chemical potential, μ₅, which is computed self-consistently as a function of temperature and field strength. We find that even if the chiral medium is produced by the fields the thermodynamics, with particular reference to the inverse catalysis induced by the external fields, it is not very affected by n₅ at least if the average μ₅, at equilibrium is not too large.

467

In this report, a kinematical focusing technique will be briefly described, and using this technique, the primary hot isotope yields from the multiplicities of evaporated light particles, associated with isotopically identified intermediate mass fragments, are reconstructed. Symmetry energy and characteristic properties of the fragmenting source at the time of the intermediate mass fragment formation are extracted from these reconstructed primary isotope yields using a self-consistent manner. The extracted density dependent symmetry energy is further compared with those experimentally extracted from other heavy-ion reactions in literatures. A direct connection between the freezeout concept and transport model simulations in a multifragmenting regime of heavy-ion collisions is also demonstrated quantitatively in the present work.

442

462

At finite baryon chemical potential, the density of a quark matter develops large fluctuations when it undergoes a first-order phase transition. Based on the transport equation derived from the Nambu-Jona-Lasinio (NJL) model, we have studied the density fluctuations in a baryon-rich quark matter that is confined in a finite volume. Allowing the expansion of the quark matter using initial conditions from either a blast wave model or a multiphase transport (AMPT) model, we have further studied the survivability of the density fluctuations as the density and temperature of the quark matter decrease. Possible experimental signatures of the density fluctuations are suggested.

598

In this talk, we first briefly review the isospin dependence of the total nucleon effective mass MJ* inferred from analyzing nucleon-nucleus scattering data within an isospin dependent non-relativistic optical potential model, and the isospin dependence of the nucleon E-mass MJ*,E obtained from applying the Migdal-Luttinger theorem to a phenomenological single-nucleon momentum distribution in nuclei constrained by recent electron-nucleus scattering experiments. Combining information about the isospin dependence of both the nucleon total effective mass and E-mass, we then infer the isospin dependence of nucleon k-mass using the well-known relation MJ∗=MJ∗,E⋅MJ∗,k. Implications of the results on the nucleon mean free path (MFP) in neutron-rich matter are discussed.

472

422

We examine the interferometry results of identical pion and kaon for the granular sources of quark-gluon plasma droplets for the Au+Au collisions at sNN=200 GeV. The effects of particle absorptions of pion and kaon on the results are investigated. We find that the absorptions lead to the decrease of the interferometry radii. After considering the absorptions, the interferometry radii of pion and kaon of the granular sources are in better agreement with the experimental data of the Au+Au collisions.

529

We study the properties of two-flavor quark matter in the equivalent particle model. A new quark mass scaling at finite temperature is proposed and applied to the thermodynamics of two-flavor quark matter. It is found that the perturbative interaction has strong effect on quark matter properties at finite temperature and high density. The pressure at the minimum free energy per baryon is exactly zero. With increasing temperature, the energy per baryon increases while the free energy per baryon decreases.

501

In this paper, by considering the electrons in different external environments, including neutral atoms, a metal, and an extremely strong magnetic-field environment, the screened α-decay half-lives of the α emitters with proton number Z=52-105 are systematically calculated. In the external environment, the decay energy and the interaction potential between α particle and daughter nucleus are both changed due to the electron screening effect and their variations are both very important for the electron screening effect. Besides, the electron screening effect is found to be closely related to the decay energy and its proton number.

480

The α-preformation factors of medium and heavy-mass nuclei are calculated by using the cluster-formation model. The obtained preformation factors of even-even, odd-A, and odd-odd nuclei consist in both magnitude and trend with the general features predicted by standard calculations. The variation of α clustering affected by the evolution of nuclear structure is observed from different behaviors of preformation factors. We typically analyze the variation of preformation factors in the closed-shell N=126 and Z=82 regions, and discuss in detail the structural effects on α-cluster formation. This work shows the strong correlation between α-preformation factors and the shell structure, which would be a useful reference for microscopic cluster-model calculations of α-decay half-lives.

431

We report our recent progress on the QCD phase structure. We explore the properties of quark-gluon matter in the improved Polyakov—Nambu—Jona-Lasinio (PNJL) model by introducing a chemical potential dependent Polyakov loop potential. This treatment effectively reflects the quantum backreaction of matter sector to glue sector at none zero chemical potential. Compared with the original PNJL model, a superiority of the improved PNJL model is that it can effectively describe the confinement-deconfinement transition at low temperature and high density. And the QCD phase diagram will be modified to a certain degree if the strength of the quantum backreaction of matter sector to glue sector is strong. One evident variation is that the region of quarkyonic phase will be greatly reduced in the improved PNJL model. This means that the modification to the Polyakov loop potential with the chemical potential dependence possibly a significant improvement in exploring the full QCD phase structure.

506

The two-particle momentum correlation is influenced by the nuclear force between two particles, which has been intensively studied for nucleons and nuclei, but not much for antinucleons or antinuclei. In this proceeding, we present our STAR measurements on momentum correlation function of antiproton-antiproton and proton-proton in Au+Au collisions at sNN = 200 GeV at the Relativistic Heavy Ion Collider (RHIC). Attractive nuclear force between two antiprotons is demonstrated and the strong interaction parameters (the scattering length and the effective range) are determined. This measurement serves as an additional verification of CPT symmetry. The present information on the strong force in the antiproton-antiproton system provides a fundamental ingredient towards understanding the structure of more sophisticated antinuclei.

514

Masks are critical elements of synchrotron radiation front-end that are exposed to high temperature and stress. The absorber material is typically comprised of dispersion strengthened copper, which can retain high performance at elevated temperature. Joining processes under vacuum, including brazing and electron beam welding, are novel approaches for prolonging the absorber and for reducing power densities. The mechanical properties of brazed joints and electron beam welded joints of dispersion strengthened copper workpieces are evaluated by tensile testing at 20 ℃, 100 ℃, and 200 ℃. The testing results indicate that the tensile strength and elongation of both vacuum joints decrease with increasing temperature. Compared to brazed joints, electron beam welded joints have higher tensile strength, better ductility, and more stable performance. A novel welded mask with a total length of 600 mm is presented, and shown to be practical for use in the highest heat load front-end in the Shanghai synchrotron radiation facility phase-II beamline project.

480

High-accuracy position monitoring of key components is required for modern synchrotron sources, such as free-electron lasers (FELs) and diffraction-limited storage rings. Although various position monitoring sensors have been adopted to monitor the displacement of key components in each direction in real time, these monitoring systems are usually based on their own coordinate system. Data from such systems are meaningful when evaluating and examining the data from each positioning monitoring system in a unified coordinate system. This paper presents the design and construction of a multi-sensor position monitoring system (MPMS) . A hydrostatic levelling system (HLS), a wire position sensor (WPS) and a tiltmetre are fixed to a stainless steel plate that has been calibrated by a coordinate-measurement machine (CMM). Several plates form the MPMS. The system must compensate for the sag of the stretched wires so that the WPSs create a straight line. The method of the coordinate transformation from the sensor coordinate system to the MPMS coordinate system was thoroughly studied. An experimental MPMS that includes five plates was setup in a 20-m tunnel, and a validation study to verify fully the feasibility of the MPMS was performed.

387

In this paper we present the general design methods and parameter measurements of a 1 kW solid-state radio frequency (RF) power amplifier at 2856 MHz, for the Soft X-ray Free Electron Laser (SXFEL) facility. Three-stage amplification with a 4-way combination is used. An RF switch module is integrated in the solid-state RF power amplifier to convert the continuous wave (CW) signal into pulse signal, with adjustable pulse width. The power gain is measured at 57.7 dB at 60 dBm output. The RF phase noise, which is measured by the low level RF system (LLRF) system, is less than 0.015 degree (RMS), while the pulse frontier jitter is less than 5 ns.

408

A facility and method for ¹⁰⁹Cd radionuclide-induced energy dispersive X-ray fluorescent (EDXRF) were developed to determine the Fe, Zn, Br, Rb, and Sr concentrations in the specimens of human prostatic fluid. Specimens of expressed prostatic fluid were obtained from 51 men (mean age 51 years, range 18-82 years) with apparently normal prostates using standard rectal massage procedure. Mean values (M ± SΕΜ) for concentration of trace elements (mg·L^-1) in human prostate fluid were: Fe 9.04±1.21, Zn 573±35, Br 3.58±0.59, Rb 1.10±0.08, and Sr ≤0.76. It was shown that the results of trace element analysis in the micro samples (20 μL) are sufficiently representative for assessment of the Fe, Zn, Br, and Rb concentration in the prostate fluid. The facility for ¹⁰⁹Cd radionuclide-induced EDXRF is comparatively compact and can be located in close proximity to the site of carrying out the massage procedure. The means of Zn and Rb concentration obtained for prostate fluid agree well with median of reported means. For the first time the Fe and Br concentrations, as well as the upper limit of the Sr concentration were determined in the human prostate fluid.

369

In this study we present a new method for the indirect integration of beam charges in external beam Proton Induced X-ray Emission and Proton Induced γ-ray Emission (PIXE-PIGE) analysis. We recorded proton spectra backscattered by a Kapton film extraction window in different sample situations and under different beam currents. We also simulated backscattering spectra using the simulation of backscattering spectra program(SIMNRA). We determined that in a specific geometrical arrangement, different sample situations did not significantly affect factor C_Q (the ratio between integral backscattering proton counts and integral beam charges). We also studied the reproducibility and beam current dependence of factor C_Q. The statistic factor of C_Q was 28.95±0.6 kilo counts /μC, with an relative standard deviation (RSD) of 2.0%. Significantly, in external beam PIXE-PIGE analysis, we were able to calculate beam charge integration from the integral backscattering proton counts in an energy region.

569

Prostate-specific membrane antigen (PSMA) is a useful target for diagnostic and therapeutic applications, and it is demonstrated that ⁶⁸Ga in conjugation with DKFZ-PSMA-617 is better than ⁶⁸Ga-PSMA-1 in biodistribution data after 1 h, but more preclinical data are still required. In this paper, we presented the additional preclinical data for ⁶⁸Ga-DKFZ-PSMA-617 and relevant aspects of its production. ⁶⁸Ga was obtained from the SnO₂ based ⁶⁸Ge/⁶⁸Ga generator. Optimum conditions (pH, temperature, time and ligand concentration) for ⁶⁸Ga-DKFZ-PSMA-617 preparation were studied. Radiochemical purity of the radiolabelled compound was determined by HPLC and RTLC. After stability assessments, the complex was intravenously injected into rats. HPLC and ITLC characterizations indicated that the radiopharmaceutical could be prepared with radiochemical purity of >96% and specific activity of 308.3 TBq/mmol at the optimized conditions (pH of 3.5-4, ligand amount of 2.4 nmol, temperature of 90-95°C and reaction time of 10 min). Also, the biodistribution data showed no undesirable uptake in non-target organs at any interval after injection. In fact, the activity is cleaned from blood and excreted rapidly via the kidneys. Generally, this compound can be considered as a well-established PET imaging agent.

439

In this paper, a novel material for Co(II) adsorption, titanate sodium nanotubes (Na₂Ti₂O₅-NTs) were synthesized and characterized, then they were used to remove Co(II) from aqueous solution and compared with titanic acid nanotubes (H₂Ti₂O₅-NTs) and potassium hexatitanate whiskers (K₂Ti₆O₁₃). The results showed that the adsorption of Co(II) on the materials was dependent on pH values and was a spontaneous, endothermic processes. Specifically, Na₂Ti₂O₅-NTs exhibited much more efficient ability to adsorb Co(II) from aqueous solution, with the maximum adsorption capacity of 85.25 mg/g. Furthermore, Na₂Ti₂O₅-NTs could selectively adsorb Co(II) from aqueous solution containing coexisting ions (Na⁺, K⁺, Mg²⁺ and Ca²⁺). The results suggested that Na₂Ti₂O₅-NTs was a potential effective adsorbent for removal of Co(II) or cobalt-60 from wastewater.

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