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Insertion into delicate tissue, such as retina vein occlusion, cell manipulation and vitreoretinal injection, poses challenges to surgeons and biomedical researchers due to the high resolution, large movement range, compact structure and multi-DOF output requirements. In order to meet these requirements, a 2-DOF arched needle insertion device driven by inertial piezoelectric actuator was proposed in this work. This device could perform theoretical unlimited translational movement and full rotation with high step resolution. A prototype was fabricated with compact structure, the length and diameter were 230 mm and 32 mm, respectively. The experimental tests were carried out, the insertion device output 2.47 m and 0.56 mrad step distance with maximum velocity of 382 m/s and 200.9 mrad/s under 120 V driving signals, the maximum insertion force of 32 mN was measured. Additionally, a handheld controller with friendly user interface was also developed for open-loop control utilization, which could automatically calculate and generate the required control signals according to the motion command. This device explores the biomedical application of inertial piezoelectric actuator within a compact size, providing a new choice for numerous innovative treatment and biological research involving precision operation.

Undulators as the sources of high-brilliance synchrotron radiation are of widespread interest in new generations of light sources and free-electron lasers. Microwave propagation in a plasma-filled elliptical waveguide can be studied as a standard short-period undulator. This structure as a lucrative insertion device can be installed in the storage ring of third- and fourth-generation light sources to produce high-energy and high-brilliance synchrotron radiation. In this article, the propagation of the transverse electric modes in a plasma-filled waveguide with an elliptical cross-section is investigated, and the field components, the cut-off frequencies and the electron beam trajectory are calculated. With due consideration of the electron beam dynamics and in order to achieve a standard short-period undulator, parameters such as the dimensions of the waveguide elliptical cross-section, the microwave frequency and the plasma density are calculated.

High energy photon source (HEPS) is the fourth-generation light source, which uses a large number of high-performance insertion devices to generate synchrotron radiation. The control system is an important part of the insertion device (ID). Cryogenic permanent magnet undulator (CPMU) is one kind of IDs that works in liquid nitrogen temperature and ultra-high vacuum environment, and its control system is more difficult and complex than in-air ID. The design of the control system for CPMU will be introduced in detail. The sub-systems include high-precision magnetic gap control, safety protection, measurement and compensation of magnetic gap at cryogenic temperature and cryogenic temperature monitoring. Mature, reliable, stable technical schemes are designed to meet the technical specifications of sub-systems. The experiment results show that the magnetic gap motion accuracy can be controlled within 0.2–0.3 μm under the step size of 1 μm. The safety protection system has been tested in turn, and the predetermined protection can be achieved. The average value of magnetic gap cold contraction is 1.512 mm measured by optical micrometer, and the compensation is realized by software. The average temperature of the main magnet structure measured by the temperature sensors is 81.0 K, and the temperature gradient is 0.7 K/m. The temperature monitoring is reliable and stable. The CPMU control system which is based on EPICS has been successfully applied to the CPMU prototype, and the test results have met the design specifications.

The use of spatial filtering with a horizontal slit near the source to enlarge the horizontal coherence in an experimental station and produce a diffraction-limited round focus at an insertion device beamline for X-ray photon correlation spectroscopy experiments is illustrated. This scheme has now been in use since 2019 for the 8-ID beamline at the Advanced Photon Source, sharing the undulator beam with two separate beamlines, 8-ID-E and 8-ID-I at 7.35 keV, with increased partially coherent flux, reduced horizontal spot sizes on samples, and good speckle contrast., This paper illustrates the use of spatial filtering with a horizontal slit near the source to enlarge the horizontal coherence in an experimental station and produce a diffraction-limited round focus at an insertion device beamline for X-ray photon correlation spectroscopy experiments. Simple expressions are provided to guide the optical layout, and wave propagation simulations confirm their applicability. The two-dimensional focusing performance of Be compound refractive lenses to produce a round diffraction-limited focus at 11 keV capable of generating a high-contrast speckle pattern of an aerogel sample is demonstrated. The coherent scattering patterns have comparable speckle sizes in both horizontal and vertical directions. The focal spot sizes are consistent with hybrid ray-tracing calculations. Producing a two-dimensional focus on the sample can be helpful to resolve speckle patterns with modern pixel array detectors with high visibility. This scheme has now been in use since 2019 for the 8-ID beamline at the Advanced Photon Source, sharing the undulator beam with two separate beamlines, 8-ID-E and 8-ID-I at 7.35 keV, with increased partially coherent flux, reduced horizontal spot sizes on samples, and good speckle contrast.

Fourth-generation storage rings (4GSR) based on multi-bend achromat (MBA) lattices promise to deliver stable X-ray beams with higher brightness and coherence than existing third-generation light sources. The basic ingredient in achieving higher brightness is a further reduction of the electron beam emittance in storage rings dedicated to light sources. These 4GSR lattices can lead to 1 to 2 orders of magnitude reductions in the beam emittance by employing a MBA, where many dipoles per cell are used to keep the dispersion function low inside the dipoles. Moreover, these low emittance beams are transported to the beam-line through the insertion device or center-bend, which is a permanent magnet with a 2 T magnetic field. In this paper, we will introduce the characteristics of the synchrotron radiation of 4GSR compared to present third-generation sources, PLS-II.

Radiation damage has been a known problem at many synchrotron radiations and free-electron lasers facilities, especially those that use hybrid or pure permanent magnet undulators to produce high brightness light. Field strength loss due to demagnetization makes it necessary to remove the insertion device from the tunnel for inspection and repair, which brings several inconveniences. We aimed to develop an in situ radiation damage detection system for undulators capable of diagnosing relative field changes of 10−4 (100 ppm) or smaller. The system measures the flux change in a flexible printed circuit board coil attached to the undulator magnet array by periodically measuring the integral flux change during the opening and closing of the undulator gap. If the magnet block damage occurs, the signal from the coil will decrease proportionally to the damage. First tests performed on variable gap hybrid undulators for the Linac Coherent Light Source II (LCLS-II) at SLAC National Accelerator Laboratory showed that the system is capable of measuring flux changes with a relative precision of approximately $0.7 \times 10^{-4}$ over several days. Relative field changes smaller than 10−4 were detected in short-term measurements. The novel system that we propose here opens the possibility of detecting radiation damage in undulators during operation.

A hybrid cryogenic permanent-magnet undulator (CPMU) with a 15-mm period length is being constructed for a TPS Phase-II beamline. A control system for this CPMU (CU15) is under development since 2018 and is based on the Experimental Physics and Industrial Control System (EPICS) architecture and Ethernet Control Automation Technology (EtherCAT) framework. The main control components include a motor with encoder for gap adjustment, corrector magnet power supplies, ion pumps and BA gauges for the vacuum system, resistance temperature detectors (RTD) and heaters for temperature control of the cryogenic environment and magnet arrays, motion safety interlock, cryogenic system and vibration monitor system. The design and implementation of the CU15 control system will be summarized in this paper.

A new beamline, XTIP, has been constructed at the Advanced Photon Source to deliver monochromatic soft X-rays of between 400 and 1900 eV for the emerging synchrotron X-ray scanning tunneling microscopy technique., In recent years, there have been numerous efforts worldwide to develop the synchrotron X-ray scanning tunneling microscopy (SX-STM) technique. Here, the inauguration of XTIP, the world’s first beamline fully dedicated to SX-STM, is reported. The XTIP beamline is located at Sector 4 of the Advanced Photon Source at Argonne National Laboratory. It features an insertion device that can provide left- or right-circular as well as horizontal- and vertical-linear polarization. XTIP delivers monochromatic soft X-rays of between 400 and 1900 eV focused into an environmental enclosure that houses the endstation instrument. This article discusses the beamline system design and its performance.

An Insertion Device (ID) is a key component of synchrotron radiation source and free electron laser. It is a periodic arrangement of diploe magnets according to Halbach rule. The precision fabrication and measurement of the ID is a crucial factor to the performance of the radiation source. A standard procedure is to measure the magnetic field quality from Hall probe measurement bench and analyze the data to extract information on phase error, field integral and straightness of the electron beam passing through the device. In this paper we report a user-friendly MATLAB code to analyze the Hall probe data. The code is used on data collected from one meter long undulator installed at Insertion Device application and Laser Instrumentation Laboratory at Devi Ahilya University, Indore, Madhya Pradesh, India.

The refrigerant flow distribution in the parallel flow microchannel evaporators is experimentally investigated to study the effect of header configuration. Six different configurations are tested in the same evaporator by installing insertion device and partition plate in the header to ensure the consistency of the other structure parameters. The results show that the uniformity of refrigerant flow distribution and the heat transfer rate are greatly improved by reducing the sectional area of header. The heat transfer rate can increase by 67.93% by reducing the sectional area of both inlet and outlet headers. The uniformity of refrigerant flow distribution and the heat transfer rate become worse after installing the partition plate in the insertion devices and changing the inner structure of the header further.