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The beam intensity of the High Intensity Heavy-ion Accelerator Facility (HIAF) is converted into current signals by beam intensity detectors and then processed by front-end electronics. The performance of the front-end electronics affects the measurement accuracy of the accelerator. To design front-end electronics to readout the current signals from a beam intensity detector. A programmable transimpedance amplifier (TIA) converts current signals into voltage signals and amplify the signals. An analog-to-digital converter (ADC) converts analog signals into digital signals under the control of ZYNQ7015. An integrated front-end electronics system was designed and verified. The electronics could collect and process current signals from 40 pA to 4 mA. The system had a higher dynamic range than traditional beam intensity measuring electronics.

We develop a formula including the low-beta effect and the influence of long cable issues for estimating the original signal of cold BPMs. A good agreement between the numerical and the measured signal with regard to two kinds of beam commissioning, helium and proton beams, in a low-beta helium and proton superconducting linac, proves that the developed numerical model could accurately estimate the output signal of cold button BPMs. Analysing the original signal between the first and the last cold BPM in the cryomodule, it is found that the signal voltage in the time domain is increased with the accelerated beam energy. However, the amplitude spectra in the frequency domain has more high frequency Fourier components and the amplitude at the first harmonic frequency reduces a lot. It results in a decline of the summed value from the BPM electronics. The decline is not proportional to a variety of the beam intensity. This is the reason why BPMs give only relative intensity and not absolute value for low-beta beams with a Gaussian distribution., Proceedings of the 15th International Conference on Heavy Ion Accelerator Technology, HIAT2022, Darmstadt, Germany

Due to limited geographic ranges, island populations, in general, are expected to have smaller population sizes and a limited influx of migrants compared to populations inhabiting continental mainlands. Therefore, island populations are expected to be influenced by genetic drift and natural selection differently from mainland populations. In this study, I aimed at investigating potential island effects in cryptic wood white (Leptidea juvernica), and the main hypothesis of this study was that island populations will show less efficient purifying selection than mainland populations. I used whole-genome re-sequencing data from three cryptic wood white butterfly populations sampled in Ireland, Kazakhstan and Sweden and applied population genomics to assess levels of genetic diversity and quantify potential variation in the efficiency of natural selection by estimating site frequency spectra, assessing population structure, and applying various types of neutrality tests. The results show that the L. juvernica population in Ireland has comparatively low nucleotide diversity and increased genetic differentiation as compared to the mainland populations. Multiple types of neutrality / selection analyses revealed that purifying selection in Ireland has been less efficient than on the mainland. These findings contribute in several ways to the understanding of how selections act in island populations and provide insights into how evolutionary genetics / genomics can be informative for conservation efforts in isolated and declining island populations and other populations with limited distribution ranges.

A noninvasive Ionization profile monitor (IPM) consisting of micro-channel plates, a phosphor screen and the optical-signal acquisition has been developed at the cooling storage ring of Heavy Ion Research Facility in Lanzhou (HIRFL-CSR). It makes the real-time profile measurements for the transverse beam cooling and orbit oscillation possible and efficient. This paper firstly describes all the IPM design criterions including the theoretical signal yield calculation, the space charge field and initial momentum evaluation, and the electrostatic field distortion simulation as well. In order to investigate the IPM performance, the beam profile measurements are done with different high voltage settings. Subsequently, some valuable beam experiments about the transverse electron cooling and orbit oscillation study are also presented. In the end, fast turn-by-turn profile measurements for the emittance blow-up research in a synchrotron are discussed. In cooperation with the newly deployed emittance instruments at the HIRFL-CSR injector, the IPM shows great prospects for the injection mismatch study, and potential values for the tune, dispersion and chromaticity measurements as well.

Stochastic cooling of the Spectrometer Ring (SRing) at the High Intensity heavy-ion Accelerator Facility (HIAF) project in China, which is used mainly for experiments with radioactive fragment beams, is applied to speed up the cooling process of a stored ion beam. In this study, both a Faltin traveling wave structure and a novel slot-ring standing wave structure based on a ceramic vacuum chamber are discussed and evaluated for the pickup/kicker of the SRing stochastic cooling system. The slot-ring structure should significantly improve the shunt impedance due to the Cherenkov effect. For the Faltin-type structure, the results for the pickup shunt impedance obtained from simulations and from beam measurements agree well. Good agreement is also found between the simulated and measured results for the pickup shunt impedance of the slot-ring structure. Cooling process simulations using the Fokker – Planck equation based on the shunt impedance results for the Faltin and slot-ring type pickups are also presented.

To meet the needs of real-time profile monitoring, injection match optimization, transverse cooling mechanism research in Cooling Storage Ring of Heavy Ion Research Facility of Lanzhou (HIRFL-CSR), and the profile measurement of future intense facilities like High Intensity Heavy-ion Accelerator Facility (HIAF) and China Initiative Accelerator Driven System (CiADS) in Huizhou China, some IPM research and experiments has been proceed since 2013. In 2016, the first IPM was developed with MCPs, phosphor screen and camera acquisition system for vertical profile monitoring in HIRFL-CSRm. Then another horizontal IPM with new framework and less field distortion was also deployed in CSRm at 2018 summer. Besides, two more IPMs will be installed in HIRFL-CSRe during next summer maintenance. This paper mainly presents the horizontal IPM design concerns, HV settings influence, some experiment anomalies, as well as experiments for transverse electron cooling and normal operation mode orbit variation at HIRFL-CSR in December 2018., Proceedings of the 8th International Beam Instrumentation Conference, IBIC2019, Malmö, Sweden

Among various cooling methods, stochastic cooling is an effective way of cooling low intensity beams with larger size. for the HIAF (High energy and high Intensity Accelerator Facility) project, stochastic cooling will be built on the SRing (Spectrometer Ring).this paper mainly concerns on cooling effect based on different stochastic cooling methods, aiming at finding the optimal cooling method and cooling parameters for different physical experiment purposes. simulation analysis will provide theoretical reference and support for the engineering construction., Proceedings of the 12th Workshop on Beam Cooling and Related Topics, COOL2019, Novosibirsk, Russia

Stochastic cooling is a broadband feedback system, which is very effective for reducing the beam size without beam loss. It has advantage over electron cooling in cooling low intensity beam with large emittance and mo-mentum spread, which is required for precise study of the decay properties of RIB (Radioactive Ion Beam) using SMS method. This paper mainly concerns on cooling of primary beam and its secondary beam, pointing out the range of mass-to-charge spread that could be cooled for secondary particles. Meanwhile, TOF cooling combined with filter cooling was also studied. The simulation results provide theoretical supports for analysing different ions circulating in the ring at the same time in the experiments., Proceedings of the 14th Int. Conf. on Heavy Ion Accelerator Technology, HIAT2018, Lanzhou, China

The effect of domestically-manufactured excimer laser with adjunctive balloon angioplasty in achieving revascularization and reduction of residual stenosis was assessed. 20 femoral arteries with thrombosis and occlusion from 12 dogs were subject to angiography. At first excimer laser angioplasty was done followed by balloon angioplasty. The diameter and residual stenosis of revascularized vessel were measured. The result showed that 17 out of 20 vessels (85%) were revascularized. The diameter of revascularized vessel by excimer laser were 1.22 +/- 0.14 mm, while residual stenoses were 54% +/- 5%. After adjunctive balloon angioplasty the diameter and residual stenoses were 2.04 +/- 0.16 mm and 20% +/- 7% respectively (P0.05 and P0.01). Complication in form of vasoperforation occurred in 3/20 vessels (15%). It is concluded that China- manufactured excimer laser angioplasty is effective when used for revascularization. While the reduction of narrowing and residual stenoses was enhanced after adjunction of balloon angioplasty. This method can be employed in treating peripheral occlusive disease effectively and safely.