A precision microwave effective linewidth measurement technique for magnetic samples has been developed. The measurement utilizes a high-Q cylindrical cavity that contains the sample of interest, a highly stable and programable static magnetic field source, a computer controlled network analyzer for cavity center frequency omega c and quality factor Qc determinations, and the standard metrologi...

PURPOSE To present a closed formalism calculating charged particle radiation damage induced in DNA. The formalism is valid for all types of charged particles and due to its closed nature is suited to provide fast conversion of dose to DNA-damage. METHODS The induction of double strand breaks in DNA-strings residing in irradiated cells is quantified using a single particle model. This leads to...

Sisyphus amplification, familiar from quantum optics, has recently been reported as a mechanism to explain the enhanced quality factor of a classical resonant (tank) circuit coupled to a superconducting flux qubit. Here we present data from a coupled system, comprising a quantum mechanical rf SQUID (flux qubit) reactively monitored by an ultrahigh quality factor noise driven rf resonator and ex...

Although DNA damage is widely viewed as a critical target for the induction of cell killing by ionising radiation, the exact nature of DNA damage responsible for these effects is unknown. To address this issue, the probability of forming lethal damage by single proton tracks, derived from published survival data for Chinese hamster V79 cells irradiated by protons with energies from 0.57 to 5.01...

We consider the statistics of the impedance Z of a chaotic microwave cavity coupled to a single port. We remove the non-universal effects of the coupling from the experimental Z data using the radiation impedance obtained directly from the experiments. We thus obtain the normalized impedance whose probability density function is predicted to be universal in that it depends only on the loss (qua...

The relative biological effectiveness (RBE) of various energy neutrons produced from a Schenkel-type accelerator at the Research Institute for Radiation Biology and Medicine, Hiroshima University (HIRRAC), compared with 60Co gamma-ray radiation was determined. The neutron radiations and gamma-ray radiation produced good linear changes in the frequency of micronuclei induced in the root-tip cell...

The paper considers the relationship between the quality of radiation and biological lesions produced by ionizing radiation. The paper provides a brief review of the modelling of induction of strand breakage, chromosome aberration, revertant mutation in bacteria and Drosophila melanogaster. Experimental data are presented for the relative biological effectiveness of helium ions and alpha-partic...

Several groups are developing ultra-miniature x-ray machines for clinical use in radiation therapy. Current systems are for interstitial radiosurgery and for intravascular insertion for irradiation to prevent re-stenosis. Typical generating voltages are low, in the 20 to 40 kV range. It is well established that the biological effectiveness of such low-energy photons is large compared with highe...

Both cell lethality and neoplastic transformation were assessed for C3H10T1/2 cells exposed to neutrons with energies from 0.040 to 13.7 MeV. Monoenergetic neutrons with energies from 0.23 to 13.7 MeV and two neutron energy spectra with average energies of 0.040 and 0.070 MeV were produced with a Van de Graaff accelerator at the Radiological Research Accelerator Facility (RARAF) in the Center f...

We examined the induction of dicentrics in human lymphocytes irradiated in vitro with nearly monoenergetic neutrons at energies in the range of 36 keV-15.0 MeV and monochromatic X-rays in the range of 1.8 keV-40 keV. For the assessment of the relative biological effectiveness (RBE) both 220 kV X-rays and Co γ-rays were used as reference radiations. To avoid potential confounding factors that wo...