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1. Monitoring electron energies during FLASH irradiations

Author

Iain D. C. Tullis, Alexander Berne, Kristoffer Petersson, Borivoj Vojnovic, and R G Newman

Subjects
Paper, Materials science, Electrons, Electron, FLASH, Linear particle accelerator, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Optics, LINAC, Radiology, Nuclear Medicine and imaging, Computer Simulation, Irradiation, Radiometry, pre-clinical radiotherapy, Range (particle radiation), Radiological and Ultrasound Technology, dosimetry, business.industry, electron beam energy, radiobiology, 030220 oncology & carcinogenesis, Cathode ray, Physics::Accelerator Physics, Radio frequency, Particle Accelerators, business, pre-clinical irradiation, Monte Carlo Method, Energy (signal processing), Beam (structure)
Abstract

When relativistic electrons are used to irradiate tissues, such as during FLASH pre-clinical irradiations, the electron beam energy is one of the critical parameters that determine the dose distribution. Moreover, during such irradiations, linear accelerators (linacs) usually operate with significant beam loading, where a small change in the accelerator output current can lead to beam energy reduction. Optimisation of the tuning of the accelerator’s radio frequency system is often required. We describe here a robust, easy-to-use device for non-interceptive monitoring of potential variations in the electron beam energy during every linac macro-pulse of an irradiation run. Our approach monitors the accelerated electron fringe beam using two unbiased aluminium annular charge collection plates, positioned in the beam path and with apertures (5 cm in diameter) for the central beam. These plates are complemented by two thin annular screening plates to eliminate crosstalk and equalise the capacitances of the charge collection plates. The ratio of the charge picked up on the downstream collection plate to the sum of charges picked up on the both plates is sensitive to the beam energy and to changes in the energy spectrum shape. The energy sensitivity range is optimised to the investigated beam by the choice of thickness of the first plate. We present simulation and measurement data using electrons generated by a nominal 6 MeV energy linac as well as information on the design, the practical implementation and the use of this monitor.

Published
2021

2. IZO deposition by RF and DC sputtering on paper and application on flexible electrochromic devices.

Author

Gomes, Lúcia, Marques, Ana, Branco, Aida, Araújo, Jorge, Simões, Mário, Cardoso, Susana, Silva, Fernando, Henriques, Inês, Laia, César A.T., and Costa, Cláudia

Subjects
*ELECTROCHROMIC devices, *SPUTTER deposition, *APPLICATION software, *INDIUM compounds, *SUBSTRATES (Materials science), *ELECTRIC conductivity, *ELECTROCHROMIC substances, *RADIO frequency
Abstract

Highlights: [•] We deposited IZO by DC Sputtering on heat sensitive substrates such as paper. [•] The materials displayed high electric conductivity and optical transparency. [•] Electrochromic materials were deposited using screen-printing. [•] Solid-state electrochromic devices were assembled, showing an excellent performance. [ABSTRACT FROM AUTHOR]

Published
2013
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3. Paper-Based RFID-Enabled Wireless Platforms for Sensing Applications.

Author

Vyas, Rushi, Lakafosis, Vasileios, Rida, Amin, Chaisilwattana, Napol, Travis, Scott, Pan, Jonathan, and Tentzeris, Manos M.

Subjects
*INK-jet printers, *ELECTRIC circuit analysis, *DETECTORS, *RADIO frequency identification systems, *ELECTRONIC amplifiers, *RADIO frequency, *WIRELESS communications, *SHORTWAVE radio
Abstract

In this paper, the feasibility of inkjet printing of circuit and microwave structures on paper-based substrates is investigated for the first time in the implementation of a complete low-cost wireless platform for sensors. First, the system-level design of the module including the amplifier characterization were carried out to ensure optimum performance of the sensor modules in the UHF bands used in RF identification communication. These results were then used to design two different antenna structures, which are printed on paper along with their respective circuit layouts using inket-printing technology. Different techniques were investigated for the assembly of circuit components on the silver printed layouts. Finally, wireless link measurements on the assembled prototypes verified the good performance on the wireless and sensing sides. [ABSTRACT FROM AUTHOR]

Published
2009
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4. RFID Tag and RF Structures on a Paper Substrate Using Inkjet-Prirrting Technology.

Author

Li Yang, Rida, Amin, Vyas, Rushi, and Tentzeris, Manos M.

Subjects
*RADIO frequency identification systems, *RADIO frequency, *INK-jet printing, *SHORTWAVE radio, *MICROWAVE circuits, *MICROSTRIP antennas, *STRIP transmission lines, *CAVITY resonators, *MICROWAVE devices, *WIRELESS LANs
Abstract

In this paper, inkjet-printed UHF and microwave circuits fabricated on paper substrates are investigated for the first time as an approach that aims for a system-level solution for fast and ultra-low-cost mass production. First, the RF characteristics of the paper substrate are studied by using the microstrip ring resonator in order to characterize the relative permittivity (ϵτ) and loss tangent (tan δ) of the substrate at the UHF band for the first time reported. A UHF RFID tag module is then developed with the inkjet-printing technology, proving this approach could function as an enabling technology for much simpler and faster fabrication on/in paper. Simulation and well-agreed measurement results, which show very good agreement, verify a good performance of the tag module. In addition, the possibility of multilayer RF structures on a paper substrate is explored, and a multilayer patch resonator bandpass filter demonstrates the feasibility of ultra-low-cost 3-D paper-on-paper RF/wireless structures. [ABSTRACT FROM AUTHOR]

Published
2007
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5. Highly Flexible and Conductive Printed Graphene for Wireless Wearable Communications Applications

Author

Xiao Zhang, Xianjun Huang, Mohammed Aqeeli, Kostya S. Novoselov, Ting Leng, Mengjian Zhu, Andre K. Geim, JiaCing Chen, KuoHsin Chang, and Zhirun Hu

Subjects
Paper, Computer science, Wearable computer, 02 engineering and technology, Communications system, Article, law.invention, Nanocomposites, law, 0202 electrical engineering, electronic engineering, information engineering, Hardware_INTEGRATEDCIRCUITS, Wireless, Graphite, Electrical conductor, Multidisciplinary, Nanocomposite, business.industry, Graphene, Electrical engineering, Electric Conductivity, 020206 networking & telecommunications, Signal Processing, Computer-Assisted, 021001 nanoscience & nanotechnology, Electric power transmission, Microscopy, Electron, Scanning, Printing, Radio frequency, 0210 nano-technology, business, Telecommunications, Porosity, Wireless Technology
Abstract

In this paper, we report highly conductive, highly flexible, light weight and low cost printed graphene for wireless wearable communications applications. As a proof of concept, printed graphene enabled transmission lines and antennas on paper substrates were designed, fabricated and characterized. To explore its potentials in wearable communications applications, mechanically flexible transmission lines and antennas under various bended cases were experimentally studied. The measurement results demonstrate that the printed graphene can be used for RF signal transmitting, radiating and receiving, which represents some of the essential functionalities of RF signal processing in wireless wearable communications systems. Furthermore, the printed graphene can be processed at low temperature so that it is compatible with heat-sensitive flexible materials like papers and textiles. This work brings a step closer to the prospect to implement graphene enabled low cost and environmentally friendly wireless wearable communications systems in the near future.

Published
2015

6. Mafet broadcasts good news on RF design tools.

Author

Ohr, Stephan

Subjects
*RADIO frequency, *PAPER, *TECHNOLOGICAL innovations
Abstract

Focuses on the White Paper issued by the eight participants in the Darpa-financed Microwave and Analog Front-End Technology (Mafet) program detailing their achievements in radio-frequency design tools. Contents of the document; Three conferences where the Mafet-inspired improvements to EDA tools were demonstrated; List of participant achievements; Criticisms of Custom Integrated Circuits Conference on Mafet Design Environment (MDE) improvements.

Published
1997