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Low Energy Particle Accelerators and Laboratories
Published in Vlado Valković, Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
The Texas Nuclear Corporation neutron generator can be used as an X-ray machine, although the neutron generator is designed primarily to accelerate ionized beams of hydrogen and deuterium. We have seen, however, that it can be adapted to accelerate heavier charged particles such as 3He ions. It is also an electron accelerator, and hence, an x-ray machine. The machine can be converted from a positive ion accelerator to an electron accelerator by simply reversing the polarity of the 150 kV (or 100 kV) power supply and the extraction and focusing power supplies in the high voltage terminal. The meter connections, of course, also have to be reversed. The HV power supply is provided with a polarity reversing switch. Conversion from a positive to negative ion accelerator can be accomplished in about a half-hour.1 Operating at 150 kV, an electron beam current of 0.5 ma or greater can be obtained.
Radiological incidents and emergencies
Published in Alan Martin, Sam Harbison, Karen Beach, Peter Cole, An Introduction to Radiation Protection, 2018
Alan Martin, Sam Harbison, Karen Beach, Peter Cole
An accident occurred in 1991 at a Teflon treatment facility in Forbach (France) where an electron accelerator irradiator was being used to treat materials. In order to save time, three workers had entered the irradiation room via an exit. Although the accelerator was switched off, the accelerating voltage was not (known as ‘dark current’ mode) and the dose rate in the room still ranged from 100 mGy/s up to several grays per second (as opposed to 80,000 Gy/s when the accelerator was on). The three received localized doses, one severe enough to produce skin lesions. The skin doses were estimated at 40 Sv (effective dose of 1 Sv) for the worker with the worst injury, and 9 and 5 Sv for the other two workers.
An Economic Success Story at Stanford
Published in Barbara Bridgman Perkins, Cancer, Radiation Therapy, and the Market, 2017
Kaplan and Ginzton’s Joint Statement about the Medical Application of the Linear Electron Accelerator was ready by February 1951.30 Written apparently for fundraising purposes, the statement acknowledged—but disparaged—existing technologies. It called Sloan devices unreliable, betatrons inflexible, synchrotrons massive, and cobalt-60 teletherapy “as yet unborn” (although its gestation was notably advanced at the time). A linear accelerator offered a “striking contrast” to these drawbacks and a serious challenge to the competition, the statement affirmed. Stanford was the natural place to develop such a device, the statement maintained, because of its strong research capabilities in both physics and radiology. At the same time, it noted that clinical outcomes from megavoltage treatment were “not dramatic,” a conclusion that Kaplan would reiterate in professional articles.31 Nonetheless, they forged ahead.
Survival study in early stages of glottis cancer, stratified by treatment
Published in Acta Oto-Laryngologica, 2022
Yolanda Lois-Ortega, Fernando García-Curdi, Héctor Vallés-Varela, Ana Muniesa-del Campo
Those patients who were treated by TLM underwent different types of CO2 laser cordectomy, depending on the size and extent of the tumor, as considered by the surgical team. On the other hand, those who received RT were treated with a linear electron accelerator, with a radiation dose between 63 and 65 Gy and a conventional fractionation of 200–225 cGy per session, completing the treatment in approximately 30 sessions. Radiation doses and volume varied very little depending on tumor size since the area to be irradiated was small. In none of the cases was treatment performed on the ganglionic chains or on the salivary glands. After completing the primary treatment, clinical and radiological follow-up of the patient was carried out periodically.
The role of women scientists in the development of ultrashort pulsed laser technology-based biomedical research in Armenia
Published in International Journal of Radiation Biology, 2022
Gohar Tsakanova, Elina Arakelova, Lusine Matevosyan, Mariam Petrosyan, Seda Gasparyan, Kristine Harutyunyan, Nelly Babayan
The development of ultrashort pulsed electron beam (UPEB) based biomedical research in Armenia became possible after the establishment of CANDLE Synchrotron Research Institute in 2002 where the AREAL (Advanced Research Electron Accelerator Lab) facility was constructed, which is a new laser driven linear accelerator for generating ultrashort relativistic electron pulses for advanced research in the fields of new acceleration concepts, novel radiation sources and applications in ultrafast life and materials sciences. A good perspective of this new approach is the possibility of an incremental upgrade of the facility energy for producing brilliant light via a Free Electron Laser.
Effects of electron beam irradiation on proteins and exopolysaccharide production and changes in Microcystis aeruginosa
Published in International Journal of Radiation Biology, 2020
Shuyu Liu, Yan Tan, Fang Ma, Hanzhuo Fu, Ying Zhang
100 mLs of algae suspension were irradiated in a 90 mm diameter glass Petri dish. The suspensions were placed under the irradiation window of a linear electron accelerator (GJ-II Xianfeng Company, Shanghai, China) with a 1.0 MeV energy and 1.0 mA beam intensity. The dose rate was 3.5 kGy/s, and different doses were got by regulating the beam and the radiation surface. The irradiation doses were controlled by setting specific irradiation time spans with the irradiation doses at 0 (control), 1.0, 2.0, 3.0, 4.0, and 5.0 kGy, respectively. Five groups of algae sample were irradiated at 0 kGy, 1.0 kGy, 2.0 kGy, 3.0 kGy, 4.0 kGy, and 5.0 kGy.