Tango Controls and data pipeline for petawatt laser experiments

The Centre for Advanced Laser Applications in Garching,Germany,is home to the ATLAS-3000 multi-petawatt laser,dedicated to research on laser particle acceleration and its applications.A control system based on Tango Controls is implemented for both the laser and four experimental areas.The device server approach features high modularity,which,in addition to the hardware control,enables a quick extension of the system and allows for automated data acquisition of the laser parameters and experimental data for each laser shot.In this paper we present an overview of our implementation of the control system,as well as our advances in terms of experimental operation,online supervision and data processing.We also give an outlook on advanced experimental supervision and online data evaluation–where the data can be processed in a pipeline–which is being developed on the basis of this infrastructure.

Single-event response of the SiGe HBT in TCAD simulations and laser microbeam experiment

In this paper the single-event responses of the silicon germanium heterojunction bipolar transistors(SiGe HBTs) are investigated by TCAD simulations and laser microbeam experiment. A three-dimensional(3D) simulation model is established, the single event effect(SEE) simulation is further carried out on the basis of Si Ge HBT devices, and then, together with the laser microbeam test, the charge collection behaviors are analyzed, including the single event transient(SET) induced transient terminal currents, and the sensitive area of SEE charge collection. The simulations and experimental results are discussed in detail and it is demonstrated that the nature of the current transient is controlled by the behaviors of the collector–substrate(C/S) junction and charge collection by sensitive electrodes, thereby giving out the sensitive area and electrode of SiGe HBT in SEE.

Improvements of Traditional Laser Fraunhofer Diffraction Experiment Using Digital Image Processing Method

We present an improved digital image processing(DIP)method to calculate the widths of single slits.Different from the traditional laser Fraunhofer diffraction experiment in college physical experiments,by performing fast Fourier transform,inverse fast Fourier transform and the nonlinear leastsquare fitting on the diffraction pattern taken by a camera,the DIP method can quickly return an analytic expression,whose period is used to calculate widths of single slits.By comparing the measured results by the DIP method and the successional difference(SD)method,we find that for a single slit whose width is 60372μm,the DIP method is more accurate.Experimental results show that for single slits with widths between 40μm and 160μm,the relative error of the DIP method is less than 2.78%.Also,the DIP method can be used to measure the diameter of filament and fibres online in real time.

Ramp-Wave Compression Experiment with Direct Laser Illumination on ShenGuang-Ⅲ Prototype Laser Facility

Ramp-wave compression experiment to balance the high compression pressure generation in aluminum and x-ray blanking effect in transparent window is demonstrated with an imaging velocity interferometer system for any reflector （VISAR） on ShenGuang-Ⅲprototype laser facility. The highest pressure is about 500 GPa after using the multilayer target design Al/Au/Al/LiF and -10^13 W//cm2 laser pulse illuminated on the planar Al target, which generates the spatial uniformity to 〈1% over 500 μm on the ablation layer. A 2-μm-thick Au layer is used to prevent the x-ray from preheating the planar ablation Al layer and window material LiF. The imaging VISAR system can be used to record the abrupt loss of the probe beam （λ= 532 nm） caused by absorption and reflection of 20-μm, 30-μm and 40-μm-thick Al, i.e., the blanking effect. Although there are slight shocks in the target, the peak pressure 500 GPa, which is the highest data up to now, is obtained with ramp-wave compression.

Primary experience of video-assisted rigid laser bronchoscopy in treatment of tracheobronchial tumors

To review the primary experience of video-assisted rigid laser bronchoscopy in the treatment of tracheobronchial tumors.Methods From Sep.2002 to Nov.2004,13 patients (15 procedures) with tracheobronchial tumors were treated with video-assisted rigid bronchoscope.Benign tumors with small pedicles were removed directly.For benign tumors with wide pedicles or tumors extending beyond the wall of air-way,total enucleating through thoracotomy were employed.In cases with malignant tumors,stenosis or obstructions were relieved by implantation of stent or cautering with electric argoulaser knife.For malignant but resectable primary tumors of trachea and main bronchi,rigid bronchoscopy might serve as a preparation of radical resection.Results Of the 5 patients with benign tumors,4 received endoscopic total resection and 1 were conversed into thoracotomy.For the 8 malignant cases,3 received stent implantation,2 had palliative ablation 3 got curative resections through thoracotomy.No peri-operative complications or death occurred in this group.Conclusion Total resection of benign tracheobronchial tumors or palliative therapy for tracheobronchial malignant stenosis or preparation of radical resection can be performed safely and efficiently by video-assisted rigid bronchoscopy.5 refs.

Compact external cavity diode laser for quantum experiments

We present a compact and practical scheme of building a ~780 nm external cavity diode laser(ECDL) whose wavelength is mainly determined by an interference filter. The Lorentzian linewidth measured by the heterodyne beating between two identical lasers is 60 k Hz, and the geometry size of the laser is only 71.5 mm×65 mm×40 mm. The linear cavity design is less sensitive to misalignment induced by mechanical and thermal disturbances, and in comparison to a common grating-based design, the sensitivity to vibration is substantially reduced. Due to its excellent performance, the laser design has already been applied to cold atom trapping experiments. This interference filter ECDL method can also be extended to other wavelengths and widen the application range of diode laser.

The Experiment and Design of Confocal Laser Scanner for Biochip

In this article ,we chiefly discuss optical part and photoelectrical part, and analyze the result data to make out the relationship between pinhole and special resolution and the influence of PMT on the result data.

Testifying experiment of the multi-pulse phenomena of capillary discharge soft-X-ray laser

In a capillary discharge experiment for the neon-like argon lasing, we have proposed an experimental scheme to verify that the multi-spike of X-ray diode （XRD） signal is a multi-pulse laser or is a reflection of the laser pulse in the XRD. The ceramic capillary has an inner diameter of 3 mm and a length of 200 mm. At the gas pressure of 28 Pa and discharge current of 27 kA, stable lasing has been realized. The experimental results prove that the multi-spike of XRD signal is a reflection of the electromagnetic signal produced by the laser pulse in the XRD. The improved electrocircuit scheme of the XRD to minimize the reflection phenomena is also found.