Video display terminals and radon.
Recent reports indicate that video display terminals (VDTs) can collect radon progeny from the air. This occurs especially when they are turned off and may have negative electric fields which attract positively charged radioactive dust. We have studied this phenomenon in detail and evaluated various techniques for removing the gettered radioactivity while the video display terminal is both off and on. We have evaluated what happens when the video display terminal is switched, thereby reversing the electric field near the screen. We have also studied possible inhalation effects by a video display terminal operator during field reversal and find that although some radioactivity may be released during the cycle, room air currents redistribute it into the room with no detectable levels being inhaled by users.
[Chromosome abnormalities caused by computer video display monitors' radiation].
OBJECTIVE
Concerns were raised about the potential damaging effects of electromagnetic field (EMF) radiation emissions of ELF (extremely low frequency) and VLF (very low frequency) computer video display monitors (VDM), it was assessed the frequency of structural chromosome abnormalities and investigated the cell cycle kinetics in individuals occupationally exposed to VDM radiation.


METHODS
Chromosome aberrations were investigated in 2,000 first cell cycle metaphases obtained after 48-hour cultures of peripheral blood lymphocytes drawn from 10 individuals occupationally exposed to VDM radiation (group E) and 10 controls (group C). Cell cycle kinetics was studied using the mitotic index (MI) and cellular proliferation index (CPI).


RESULTS
Statistical analysis showed significantly higher frequencies of anomalous metaphases (E=5.9%; C=3.7%) and anomaly/cell (E=0.066+/-0.026; C= 0.040+/-0.026) in individuals exposed to VDM radiation. The most common cytogenetic alterations seen were chromatid breaks at frequencies of 0.034+/-0.016 in group E and 0.016+/-0.015 in group C. There was no significant difference between MI and CPI frequencies in both groups.


CONCLUSIONS
The study findings suggest genotoxic effects of EMF emissions revealed by the higher frequency of chromatid breaks in individuals exposed to VDM radiation. However, there is a need of further studies on EMF genetic effects using other investigation methods.
ELECTROMAGNETIC DESIGN OF A RADIO FREQUENCY QUADRUPOLE FOR THE FRONT END TEST STAND AT RAL
The goal of the RAL front end test stand is to demonstrate cleanly chopped bunches of a 60mA H − ion beam at 3MeV. The acceleration of the H − ions from 65keV to 3MeV will be done using a radio frequency quadrupole (RFQ) operating at a resonant frequency of 324MHz. The two types of RFQ considered were a 4-vane and a 4-rod. The 4-vane has a higher Q-value but the post-production adjustment is limited. The 4-rod design is easier to manufacture but requires complicated cooling at 324MHz. The results of electromagnetic simulations using CST Microwave Studio are presented for the 4-vane type and 4-rod type RFQ.