Advance in in-beam PET

Tumor radiotherapy was a promising modality and over 100 years. Beams of heavy-charged particles show high RBE advantages and become the optimum tool for tumors therapy. Newly, along with the development of accelerators, scintillators, micro-electronics and computers, the heavy ion tumor therapy has been recognized more and developed.

A proposal design of a multi-hit two-dimensional position-sensitive energy spectrum detector

A new non-linear comparison method of charge-division readout scheme is conceived and the first design of a multi-hit two-dimensional position-sensitive energy spectrum Si(Au) surface barrier detector with a continuous sensitive area is proposed.

Research on metallic ion beam production at IMP

Since 1998, many experiments for metallic ion production have been done on LECR2 (Lanzhou ECR ion source NO.2), LECR3 (Lanzhou ECR ion source NO.3) and SECRAL (Superconductiong ECR ion source Advanced design in Lanzhou) at Institute of Modern Physics. The very heavy metallic ion beams such as those of uranium were also produced by the plasma sputtering method, and supplied for HIRFL (Heavy Ion Research Facility in Lanzhou) accelerators successfully. During the test, 11.5e mu AU(28+), 9e mu AU(24+) were obtained. Some ion beams of the metal having lower melting temperature such as Ni and Mg ion beams were produced by oven method on LECR3 too. The consumption rate was controlled to be lower for Mg-26 ion beams production, and the minimum consumption was about 0.3mg per hour. In this paper, the main experimental results are given. Some discussions are made for some experimental phenomena and results, and some conclusions are drawn.

Development of multi-channel gated integrator and PXI-DAQ system for nuclear detector arrays

A multi-channel gated integrator and PXI based data acquisition system have been developed for nuclear detector arrays with hundreds of detector units. The multi-channel gated integrator can be controlled by a programmable Cl controller. The PXI-DAQ system consists of NI PXI-1033 chassis with several PXI-DAQ cards. The system software has a user-friendly GUI which is written in C language using LabWindows/CVI under Windows XP operating system. The performance of the PXI-DAQ system is very reliable and capable of handling event rate up to 40 kHz. (C) 2010 Elsevier B.V. All rights reserved.

A high performance Time-of-Flight detector applied to isochronous mass measurement at CSRe

A high performance Time-of-Flight detector has been designed and constructed for isochronous mass spectrometry at the experimental Cooler Storage Ring (CSRe) The detector has been successfully used in an experiment to measure the masses of the N approximate to Z approximate to 33 nuclides near the proton drip-line Of particular interest is the mass of As-65 A maximum detection efficiency of 70% and a time resolution of 118 +/- 8 Ps (FWHM) have been achieved in the experiment The dependence of detection efficiency and signal average pulse height (APH) on atomic number Z has been studied The potential of APH for Z identification has been discussed (C) 2010 Elsevier B V All rights reserved

STATUS AND PROSPECTS OF HIRFL EXPERIMENTS ON NUCLEAR PHYSICS

HIRFL is an accelerator complex consisting of 3 accelerators, 2 radioactive beams lines, 1 storage rings and a number of experimental setups. The research activities at HIRFL cover the fields of radio-biology, material science, atomic physics, and nuclear physics. This report mainly concentrates on the experiments of nuclear physics with the existing and planned experimental setups such as SHANS, RIBLL1, ETF, CSRe, PISA and HPLUS at HIRFL.

谐振式电子加速器电子枪注入控制系统

电子加速器作为一种工业化设备已经在各个领域得到了广泛的应用，它的内部控制电路工作在高电压环境中，尤其是高电压端存在的各种干扰对其稳定性影响很大，使得高压端的控制显得很困难，由于以往使用的高压端控制电路常常发生损坏，因此本文就高压端控制进行了讨论，并从原理和元器件设计方面考虑来解决这些问题。本文对大功率谐振式电子加速器的用途、工作原理以及总体结构做了简要的介绍，同时主要阐述了电子加速器电子枪注入控制系统的原理设计、总体结构以及实验结果。本文对以往使用的控制回路在高压端工作时其存在的问题进行了分析，比较了两种方案的优缺点，主要从电路的抗干扰和抗电流冲击以及稳定性出发对电路的各个部分进行了合理的设计，重点对组成电路的各个单元进行了详细的原理介绍和设计计算，而且对整个系统进行了SIM 99仿真，得到了合理的结果，与实验过程中所测数据完全一致。通过对电路的实际调试和分析可以看出该系统比旧系统在抗干扰和可靠性方面有大幅度的提高

A multichannel detector array with 768 pixels developed for electron spectroscopy

Langstaff, David; Chase, T., (2007) 'A multichannel detector array with 768 pixels developed for electron spectroscopy', Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 573(1-2) pp.169-171 RAE2008

Accelerating Internet Streaming Media Delivery Using Network-Aware Partial Caching

Internet streaming applications are adversely affected by network conditions such as high packet loss rates and long delays. This paper aims at mitigating such effects by leveraging the availability of client-side caching proxies. We present a novel caching architecture (and associated cache management algorithms) that turn edge caches into accelerators of streaming media delivery. A salient feature of our caching algorithms is that they allow partial caching of streaming media objects and joint delivery of content from caches and origin servers. The caching algorithms we propose are both network-aware and stream-aware; they take into account the popularity of streaming media objects, their bit-rate requirements, and the available bandwidth between clients and servers. Using realistic models of Internet bandwidth (derived from proxy cache logs and measured over real Internet paths), we have conducted extensive simulations to evaluate the performance of various cache management alternatives. Our experiments demonstrate that network-aware caching algorithms can significantly reduce service delay and improve overall stream quality. Also, our experiments show that partial caching is particularly effective when bandwidth variability is not very high.

Secure architectures for pairing based public key cryptography

Along with the growing demand for cryptosystems in systems ranging from large servers to mobile devices, suitable cryptogrophic protocols for use under certain constraints are becoming more and more important. Constraints such as calculation time, area, efficiency and security, must be considered by the designer. Elliptic curves, since their introduction to public key cryptography in 1985 have challenged established public key and signature generation schemes such as RSA, offering more security per bit. Amongst Elliptic curve based systems, pairing based cryptographies are thoroughly researched and can be used in many public key protocols such as identity based schemes. For hardware implementions of pairing based protocols, all components which calculate operations over Elliptic curves can be considered. Designers of the pairing algorithms must choose calculation blocks and arrange the basic operations carefully so that the implementation can meet the constraints of time and hardware resource area. This thesis deals with different hardware architectures to accelerate the pairing based cryptosystems in the field of characteristic two. Using different top-level architectures the hardware efficiency of operations that run at different times is first considered in this thesis. Security is another important aspect of pairing based cryptography to be considered in practically Side Channel Analysis (SCA) attacks. The naively implemented hardware accelerators for pairing based cryptographies can be vulnerable when taking the physical analysis attacks into consideration. This thesis considered the weaknesses in pairing based public key cryptography and addresses the particular calculations in the systems that are insecure. In this case, countermeasures should be applied to protect the weak link of the implementation to improve and perfect the pairing based algorithms. Some important rules that the designers must obey to improve the security of the cryptosystems are proposed. According to these rules, three countermeasures that protect the pairing based cryptosystems against SCA attacks are applied. The implementations of the countermeasures are presented and their performances are investigated.

Wound healing dressings and drug delivery systems: a review

The variety of wound types has resulted in a wide range of wound dressings with new products frequently introduced to target different aspects of the wound healing process. The ideal dressing should achieve rapid healing at reasonable cost with minimal inconvenience to the patient. This article offers a review of the common wound management dressings and emerging technologies for achieving improved wound healing. It also reviews many of the dressings and novel polymers used for the delivery of drugs to acute, chronic and other types of wound. These include hydrocolloids, alginates, hydrogels, polyurethane, collagen, chitosan, pectin and hyaluronic acid. There is also a brief section on the use of biological polymers as tissue engineered scaffolds and skin grafts. Pharmacological agents such as antibiotics, vitamins, minerals, growth factors and other wound healing accelerators that take active part in the healing process are discussed. Direct delivery of these agents to the wound site is desirable, particularly when systemic delivery could cause organ damage due to toxicological concerns associated with the preferred agents. This review concerns the requirement for formulations with improved properties for effective and accurate delivery of the required therapeutic agents. General formulation approaches towards achieving optimum physical properties and controlled delivery characteristics for an active wound healing dosage form are also considered briefly.

Correlating Additives to Deterioration and Assessing the Effectiveness of Acrylic Coatings for the Protection of Rubber

Conservators have long been aware of the problems associated with the preservation of rubber objects due to inherent instability that can be attributed, in part, to the presence of additives. Inorganic additives, such as fillers, accelerators, stabilizers, and special ingredients are necessary in manufacturing to alter the properties of natural rubber. These materials all have different interactions with the rubber, and each other, and differing effects on the ageing process. To date, the most effective and accepted methods to preserve rubber are cold, dark storage of objects, or the use of low oxygen environments. While these methods are effective, they greatly limit access. The application of coatings to the surface of rubber objects can slow deterioration and greatly increase the ability of an institution to handle and display rubber objects. While numerous coatings for preventive and interventive treatment have been tested, none have been so successful to warrant routine use. The first section of this research highlighted the relationship between the inclusion of certain additives in natural rubber objects and the accelerated or slowed down overall degradation. In the second part of this research, the acrylic varnishes Golden Polymer Varnish with UVLS, Lascaux Acrylic Transparent Varnish-UV, Sennelier Matte Lacquer with UV Protection, and Liquitex Soluvar Varnish containing ultraviolet light absorbers or stabilizers were tested as a preventative coating for rubber. Through testing the visual and physical properties of the samples, as well as compound analysis the results of this research suggest that acrylic varnishes do provide protection, each to varying degrees. The results also provided insight into the behavior of rubber and these varnishes with continuing light exposure.

Laser-driven proton scaling laws and new paths towards energy increase

The past few years have seen remarkable progress in the development of laser-based particle accelerators. The ability to produce ultrabright beams of multi-megaelectronvolt protons routinely has many potential uses from engineering to medicine, but for this potential to be realized substantial improvements in the performances of these devices must be made. Here we show that in the laser-driven accelerator that has been demonstrated experimentally to produce the highest energy protons, scaling laws derived from fluid models and supported by numerical simulations can be used to accurately describe the acceleration of proton beams for a large range of laser and target parameters. This enables us to evaluate the laser parameters needed to produce high-energy and high-quality proton beams of interest for radiography of dense objects or proton therapy of deep-seated tumours.