Continuous Wave Microwave Research Articles

Role of modulation on the effect of microwaves on ornithine decarboxylase activity in L929 cells.

The effect of 835 MHz microwaves on the activity of ornithine decarboxylase (ODC) in L929 murine cell was investigated at an SAR of approximately 2.5 W/kg. The results depended upon the type of modulation employed. AM frequencies of 16 Hz and 60 Hz produced a transient increase in ODC activity that reached a peak at 8 h of exposure and returned to control levels after 24 h of exposure. In this case, ODC was increased by a maximum of 90% relative to control levels. A 40% increase in ODC activity was also observed after 8 h of exposure with a typical signal from a TDMA digital cellular telephone operating in the middle of its transmission frequency range (approximately 840 MHz). This signal was burst modulated at 50 Hz, with approximately 30% duty cycle. By contrast, 8 h exposure with 835 MHz microwaves amplitude modulated with speech produced no significant change in ODC activity. Further investigations, with 8 h of exposure to AM microwaves, as a function of modulation frequency, revealed that the response is frequency dependent, decreasing sharply at 6 Hz an 600 Hz. Exposure with 835 MHz microwaves, frequency modulated with a 60 Hz sinusoid, yielded no significant enhancement in ODC activity for exposure times ranging between 2 and 24 h. Similarly, exposure with a typical signal from an AMPS analog cellular telephone, which uses a form of frequency modulation, produced no significant enhancement in ODC activity. Exposure with 835 MHz continuous wave microwaves produced no effects for exposure times between 2 and 24 h, except for a small but statistically significant enhancement in ODC activity after 6 h of exposure. Comparison of these results suggests that effects are much more robust when the modulation causes low-frequency periodic changes in the amplitude of the microwave carrier.

S-Band FMCW Radar Measurements of Ocean Surface Dynamics

Abstract A ground-based frequency-modulated continuous wave microwave radar has been developed and applied to the measurement of ocean surface velocities. Full Doppler spectra are available, and both range and lime variations of the surface drifts can be recorded with resolutions down to 2.5 m and 0.3 s, respectively, over range extents of up to 1000 m. The ability of the radar to provide information over a wide range of sea conditions is demonstrated. These range from the identification of 5-cm scattering waves and their damping by a surface slick, to the propagation characteristics of long (∼200 m) ocean waves in deep and shallow water. The longwave propagation is in accord with linear wave theory. The relationship of the backscattered power at low grazing angles to the wave features is also demonstrated. The consequences of measuring radial velocity components at low grazing angles with a narrow beam antenna are considered. In this situation, wave height spectra and the principal wave direction are wel...

A compact electron cyclotron resonance source for 200-2000 eV ion beams

Ion-beam-sputtered and -assisted deposition technologies need medium energy, 100-2000 eV, ion beams of current density 1-3 mA cm-2, operated in a reactive and corrosive gas environment. We designed, built and characterized a compact electron cyclotron resonance ion beam source generating 2 cm diameter ion beams with currents of 2-8 mA and energy 200-1700 eV. Continuous wave microwave power (2.45 GHz, P1=0-300 W) was introduced into a 5 cm diameter plasma chamber via a 50 omega cable and a half-wavelength antenna. A ceramic cup sealed the plasma chamber and separated the antenna from the plasma. Boron nitride spacers electrically isolated the high-voltage plasma from the earthed chamber walls. Two Sm-Co ring-shaped magnets formed a circular electron cyclotron resonance surface in the plasma generation zone near the microwave introduction point. An external magnetic coil generated in the chamber an axial magnetic field, which helped to ignite the plasma and to control the plasma shape and density. The ignition microwave power was 5-40 W, with operational (argon) pressures in the beam line of 2*10-5 to 2*10-4 Torr. An argon ion beam was extracted using two multi-aperture pyrolitic graphite grids: a positive plasma grid and a negative electron suppression grid. The ion beam current increased linearly with microwave power; the beam half-angle divergence near the target was alpha /2=4-6.

The dependence of microwave backscatter from the sea on illuminated area: Correlation times and lengths

During the Synthetic Aperture Radar (SAR) and X band Ocean Nonlinearities‐Forschungsplattform Nordsee experiment, we mounted two continuous wave microwave systems on an elevator on the German Research Platform Nordsee for the purpose of investigating the dependence of microwave backscatter from the sea surface on illuminated area. The two systems operated at X and Ka bands (10 and 35 GHz) and collected HH and VV polarized backscattered signals simultaneously. The elevator system allowed us to vary the altitude of the two microwave systems above the sea surface from 7.5 to 27 m, always in the far field of the antennas. Most data were collected at a 45° incidence angle, which implied that the Ka band system illuminated areas from 0.4 to 6.0 m2 while the X band system viewed spots between 2.9 and 41.3 m2. We examined the dependence of the normalized radar cross section (σ0), its variance, and the bandwidth of the Doppler spectrum on illuminated areas. We were unable to detect any dependence of σ0 on area but found a definite decrease in its variance as area increased. At X band the variance divided by the square of σ0, the normalized variance, decreased from values near 12 for small areas to values near 2 for large areas. At Ka band, corresponding values were 40 and 2. The normalized variance was always slightly larger for HH polarization. By fitting the area dependence of the normalized variance to available theory, we deduce that correlation lengths are on the order of 10 times the microwave wavelength at both X and Ka band. Values for the normalized variance of an elementary scattering facet were also inferred and are presented in this paper. From the Doppler bandwidths we obtained radial velocity spreads over the illuminated areas and found that they agreed well at X and Ka band. These velocity spreads, which are inversely proportional to the correlation time of the backscatter, increased rapidly with illuminated area for small areas but tended to level off to values of about 0.5 m s−1 at large areas. This implies a decorrelation time for large illuminated areas of about 10 ms at X band and 3 ms at Ka band but somewhat larger values for small areas. The dependence of the velocity spread was found to be well explained by theory if an intrinsic velocity spread of 0.07 m s−1 was used to represent scatterer lifetime effects.

Microwave backscatter from the sea: Modulation of received power and Doppler bandwidth by long waves

Two continuous wave microwave systems were mounted on an elevator on the German Forschungsplattform Nordsee (FPN) during the Synthetic Aperture and X Band Ocean Nonlinearities (SAXON)‐FPN experiment. Here we report on measurements of long‐wave effects in the power received by these systems and in the Doppler bandwidths recorded from the systems. The two systems operated at X and Ka bands (10 and 35 GHz) and collected HH‐ and VV‐polarized backscatter signals simultaneously. The elevator system allowed us to vary the altitude of the microwave antennas above the sea surface from 7.5 to 27 m, always in the far field of the antennas. Most data were collected at a 45° incidence angle, which implied that the Ka band system illuminated areas from 0.4 to 6.0 m2 while the X band system viewed spots between 2.9 and 41.3 m2. We have attempted to characterize the modulation of both received power and Doppler bandwidth in terms of the standard modulation transfer function (MTF) concept. We find that our measurements of the MTF for received power agree well with previous measurements at X band but that the phase of the MTF for VV polarization is different from that previously reported for Ka band at a 60° incidence angle. We show how the amplitude and phase of the MTF as well as the coherence function vary with wind speed, long‐wave frequency, long‐wave propagation direction, and antenna height. In the case of the first three parameters our results agree with previous work except as noted above for Ka band. The dependence of the MTF on antenna height has not been investigated previously. Our results show that this dependence is small and well explained by the height variations induced as long waves propagate through the footprint on the surface. When we apply the MTF concept to the Doppler bandwidth, we find that the MTF of the bandwidth is small except at very low wind speeds. In view of the association of this bandwidth with velocities of subresolution‐scale, or intermediate‐scale, waves which are themselves modulated by the long waves, we find these small MTFs associated with Doppler bandwidths to be somewhat surprising. We present a simple model to attempt to draw inferences about the amplitude modulation of intermediate‐scale waves from our results. We also conclude from the small MTFs for Doppler bandwidths that the assumption of a constant correlation time in theories of synthetic aperture radar imagery of the ocean is well justified.

Electron density and collision frequency of microwave-resonant-cavity-produced discharges

A review of perturbation diagnostics applied to microwave resonant cavity discharges is presented. The classical microwave perturbation technique examines the shift in the resonant frequency and cavity quality factor of the resonant cavity caused by low-electron density discharges. However, the modifications presented allow the analysis to be applied to discharges with electron densities beyond the limit predicted by perturbation theory. An ‘‘exact’’ perturbation analysis is presented which models the discharge as a separate dielectric, thereby removing the restrictions on electron density imposed by the classical technique. The ‘‘exact’’ method also uses measurements of the shifts in the resonant conditions of the cavity. Third, an electromagnetic analysis is presented which uses a characteristic equation, based upon Maxwell’s laws, and predicts the discharge conductivity based upon measurements of a complex axial wave number. By allowing the axial wave number of the electromagnetic fields to be complex, the fields are experimentally and theoretically shown to be spatially attenuated. The diagnostics are applied to continuous-wave microwave (2.45 GHz) discharges produced in an Asmussen resonant cavity. Double Langmuir probes, placed directly in the discharge at the point where the radial electric field is zero, act as a comparison with the analytic diagnostics. Microwave powers ranging from 30 to 100 W produce helium and nitrogen discharges with pressures ranging from 0.5 to 6 Torr. Analysis of the data predicts electron temperatures from 5 to 20 eV, electron densities from 1011 to 3×1012 cm−3, and collision frequencies from 109 to 1011 s−1.

Double Langmuir probe diagnostic of a resonant cavity microwave discharge

An Asmussen resonant cavity operating at 2.45 GHz provides the basis for the application of probe theory to a microwave discharge. A double Langmuir probe is inserted into a discharge produced by a microwave resonant cavity. Typical operating pressures range from 0.5 to 50 Torr in helium, with continuous wave microwave powers ranging from 60 to 120 W at 2.45 GHz. Typical probe data indicates electron densities in the range of 1011–1012 cm−3 with electron temperatures of 5 to 20 eV. The probe data is compared with the results of a model based upon the electromagnetics of the discharge.

The influence of oxygen-17 enriched oxygen-donor ligands on the electronic spin relaxation behaviour of paramagnetic metal ions

Continuous wave microwave power saturation of high-spin paramagnetic metalloprotein complexes of Co2+ and Fe3+ showed that the value of the saturation parameter P 1/2 is influenced by the coordination of oxygen-17 enriched water to the metal ion. No change was observed for H2 18O or 2H2O. Pulse saturation and recovery of paramagnetic high-spin Fe3+ heme proteins identified a fast relaxation component sensitive to isotopic oxygen-17 composition that was assigned to the process of spectral diffusion. It is shown that the change in relaxation time for spectral diffusion can alter the (apparent) spin-lattice relaxation to account for the observed changes in continuous wave microwave power saturation experiments. These changes are shown to correlate with alterations in the extent of covalency between the metal ion and oxygen-donor ligand. The experimental results provide a basis for use of continuous wave microwave saturation to identify the presence of oxygen-donor ligands within the inner coordination shell ...

A combined continuous-wave and pulsed microwave copper chloride discharge

Pulsed and continuous-wave microwaves at 2.45 GHz combined in an Asmussen resonant cavity are used to vaporize, dissociate, and excite copper chloride discharges. Steady state microwaves from 50 to 150 W sustain a microwave discharge which heats and dissociates the copper chloride to a sufficient vapor pressure. A variable frequency (2.45 to 2.60 GHz) pulsed microwave source with pulse widths ranging from 0.5 to 2 ms, repetition rates of 500 to 5000 Hz and a peak output power of 4,500 W then excites the copper atomic states. The two microwave signals are superimposed using a hybrid junction before input into the resonant cavity. Microwave frequencies of the pulsed portion of the signal around 2.50 GHz provided maximum absorption by the discharge. This device is being examined as a potential pump source for a copper vapor laser.

Microwave Exposure Alters the Expression of 2-5A-Dependent RNase

The effects of 2.45-GHz continuous-wave microwaves (SAR = 130 mW/g) on the expression of the interferon-regulated enzymes 2'-5'-oligoadenylate (2-5A) synthetase(s) and 2-5A-dependent endoribonuclease (RNase L) were studied in murine L929 cells. Cells growing as monolayers were removed from the substratum and placed in suspension culture for a 4-h sham or microwave exposure. The cells were returned to monolayer growth for 18 h, and then harvested and assayed to determine the amount of RNase L protein (via [32P]2-5A binding) and the specific activities of RNase L and 2-5A synthetase. Binding of radioactive 2-5A to RNase L for sham- and microwave-exposed samples was 14.5 and 36.4% above control, respectively (the microwave-exposed bound 19.0% more probe than the sham-exposed). The increases in 2-5A binding were accompanied by corresponding elevations of RNase L specific activity. In contrast, sham or microwave irradiation produced no alterations in 2-5A synthetase specific activity. No detectable differences were noted in the postexposure cell viability, plating efficiency, or proliferation rate. Also, there were no detectable differences in cell viability or plating efficiency between controls and cultures irradiated for 2 h when the temperature was simultaneously increased to above normal physiological limits (39 to 45 degrees C). The SAR (130 mW/g) and the power density (95 mW/cm2) used for the greater part of this study were nearly 20 times higher than the ANSI limit of 8 mW/g and 5 mW/cm2 for any 1 g of exposed human tissue.

Results of a United States and Soviet Union joint project on nervous system effects of microwave radiation.

During the course of a formal program of cooperation between the United States and the Soviet Union concerning the biological effects of physical factors in the environment, it was concluded that duplicate projects should be initiated with the general goal of determining the most sensitive and valid test procedures for evaluating the effects of microwave radiation on the central nervous system. This report details an initial step in this direction. Male rats of the Fischer 344 strain were exposed or sham exposed to 10 mW/cm2 continuous wave microwave radiation at 2.45 GHz for a period of 7 hr. Animals were subjected to behavioral, biochemical, or electrophysiological measurements during and/or immediately after exposure. Behavioral tests used were passive avoidance and activity in an open field. Biochemical measurements were ATPase (Na+, K+; Mg2+, Ca2+) and K+ alkaline phosphatase activities. Electrophysiological measurements consisted of EEG frequency analysis. Neither group observed a significant effect of microwave irradiation on open field activity. Both groups observed changes in variability of the data obtained using the passive avoidance procedure, but not in the same parameters. The U.S. group, but not the USSR group, found significantly less Na+,K+-ATPase activity in the microwave-exposed animals compared to the sham exposed animals. Both groups found incidences of statistically significant effects in the power spectral analysis of EEG frequency, but not at the same frequency. The failure of both groups to substantiate the results of the other reinforces our contention that such duplicate projects are important and necessary.

Acute low-level microwave exposure and central cholinergic activity: studies on irradiation parameters.

Sodium-dependent high-affinity choline uptake was measured in the striatum, frontal cortex, hippocampus, and hypothalamus of rats after acute exposure (45 min) to pulsed (2 microseconds, 500 pps) or continuous-wave 2,450-MHz microwaves in cylindrical waveguides (Guy et al.: Radio Science 14:63-74, 1979) or miniature anechoic chambers (Guy: Journal of Microwave Power 14:327-338, 1979). In all exposure conditions, the average whole-body specific absorption rate was at 0.6 W/kg. Decrease in choline uptake was observed in the frontal cortex after microwave exposure in all of the above irradiation conditions. Regardless of the exposure system used, hippocampal choline uptake was decreased after exposure to pulsed but not continuous-wave microwaves. Striatal choline uptake was decreased after exposure to either pulsed or continuous-wave microwaves in the miniature anechoic chamber. No significant change in hypothalamic choline uptake was observed under any of the exposure conditions studied. We conclude that depending on the parameters of the radiation, microwaves can elicit specific and generalized biological effects.

Serum enzymes in hemorrhaged Japanese quail after microwave irradiation during embryogeny

1. 1. Japanese quail eggs were exposed to 2.45 GHz continuous wave microwave radiation at an incident power density of 5 mW/cm 2 and a specific absorption rate of 4.03 mW/g during the first 12 days of embryogeny. 2. 2. After hatching, serum biochemical changes in response to hemorrhagic stress were measured following a hemorrhage of 30% of the calculated total blood volume. 3. 3. Lactate dehydrogenase, β-glucuronidase, acid phosphatase, glucose and protein were not affected by microwave irradiation during embryogeny either before or after hemorrhage. 4. 4. Microwave irradiation in ovo affected the response of serum glutamic oxaloacetic transaminase activity to hemorrhagic stress in Japanese quail.

Studies of the induction of dominant lethals and translocations in male mice after chronic exposure to microwave radiation.

Male C3H mice were exposed to 100 W m-2 of 2.45 GHz continuous-wave microwave radiation for 6 h per day for a total of 120 h over an 8-week period. The exposure level was chosen so that the specific energy absorption rate (SAR) would be approximately equal to the level of 4 W kg-1 which is considered by a number of organizations to be a threshold for adverse biological effects. At the end of the treatment period the mice were mated with a different group of (C3H x 101) F1 hybrid females each week for the following 8 weeks. There was no significant reduction in pregnancy rate, preimplantation survival or postimplantation survival in the exposed group compared to sham-exposed controls. At the end of the mating period a cytogenetic analysis was carried out of meiotic chromosome preparations of testicular tissue, thus sampling cells that were stem cell spermatogonia during the treatment regime. The results showed no difference in the frequency of reciprocal translocations between the sham and treated groups, or in the frequency of cells with autosome or sex chromosome univalents. Low levels of fragments and exchanges were found in both groups. It is concluded that there is no evidence in this experiment to show that chronic exposure of male mice to 2.45 GHz microwave radiation induces a mutagenic response in male germ cells. This conclusion is in agreement with the observations of Berman et al. (1980), who reported a lack of male germ cell mutagenesis after repetitive or chronic exposure of rats to 2.45 GHz.

In vitro studies of microwave-induced II. Comparison of damage observed for continuous wave and pulsed microwaves

Depth of damage caused by pulsed (PU) and continuous wave (CW) microwaves was estimated by scanning electron microscopy in rat lenses fixed immediately, after irradiation in vitro in circulating thermostatically controlled buffered saline. Pulses of 10 microseconds width and 24 kW peak power were delivered to the lens at different repetition rates in order to permit the same total energy to be delivered during 6, 20 or 60 min of irradiation at specific absorption rate (SAR) values of 0, 5.75, 11.5, 23, 69, 231 and 750 mW g-1; total energy [power (pow) x time] deposited in the lens was 0, 0.23, 0.46, 1.38, 4.6, and 15 W min g-1. Damage (granular degeneration of cells at the lens equator) was measured at the apex of penetration of the degeneration. The depth of degeneration (dep) of Pu or CW was compared either: (1) by a one-way analysis of variance (ANOVA) for the CW data alone and the 11 combinations of (pow x time); or (2) by using two alternative models to fit the data, to permit experimental distinguishment between: (a) reciprocal effects of pow x time; and (b) separate effects. Using the ANOVA analysis, the Pu mode of irradiation resulted in more damage at the same average power for every combination tested except one (23 mW g-1, 6 min). Although the separate-effects models explained more of the variation in depth of damage, the reciprocal effects model may provide an adequate fit for practical purposes and has the advantage of greater simplicity. For both models, the pulsed irradiation mode produced 4.7 times the depth of damage caused by CW irradiation. These results are discussed in relation to previous Pu-CW comparisons. It is proposed that this additional damage at the same average power is caused by thermoelastic expansion (TEE).

Thermoregulatory responses of the immature rat following repeated postnatal exposures to 2,450-MHz microwaves.

This study was designed to determine the changes that occur in the thermoregulatory ability of the immature rat repeatedly exposed to low-level microwave radiation. Beginning at 6-7 days of age, previously untreated rats were exposed to 2,450-MHz continuous-wave microwaves at a power density of 5 mW/cm2 for 10 days (4 h/day). Microwave and sham (control) exposures were conducted at ambient temperatures (Ta) which represent different levels of cold stress for the immature rat (ie, "exposure" Ta = 20 and 30 degrees C). Physiological tests were conducted at 5-6 and 16-17 days of age, in the absence of microwaves, to determine pre- and postexposure responses, respectively. Measurements of metabolic rate, colonic temperature, and tail skin temperature were made at "test" Ta = 25.0, 30.0, 32.5, and 35.0 degrees C. Mean growth rates were lower for rats exposed to Ta = 20 degrees C than for those exposed to Ta = 30 degrees C, but microwave exposure exerted no effect at either exposure Ta. Metabolic rates and body temperatures of all exposure groups were similar to values for untreated animals at test Ta of 32.5 degrees C and 35.0 degrees C. Colonic temperatures of rats repeatedly exposed to sham or microwave conditions at exposure Ta = 20 degrees C or to sham conditions at exposure Ta = 30 degrees C were approximately 1 degrees C below the level for untreated animals at test Ta of 25.0 degrees C and 30.0 degrees C. However, when the exposure Ta was warmer, rats exhibited a higher colonic temperature at these cold test Ta, indicating that the effectiveness of low-level microwave treatment to alter thermoregulatory responses depends on the magnitude of the cold stress.

Temperature-specific inhibition of human red cell Na+/K+ ATPase by 2,450-MHz microwave radiation.

The ATPase activity in human red blood cell membranes was investigated in vitro as a function of temperature and exposure to 2,450-MHz continuous wave microwave radiation to confirm and extend a report of Na+ transport inhibition under certain conditions of temperature and exposure. Assays were conducted spectrophotometrically during microwave exposure with a custom-made spectrophotometer-waveguide apparatus. Temperature profiles of total ATPase and Ca+2 ATPase (ouabain-inhibited) activity between 17 and 31 degrees C were graphed as an Arrhenius plot. Each data set was fitted to two straight lines which intersect between 23 and 24 degrees C. The difference between the total and Ca+2 ATPase activities, which represented the Na+/K+ ATPase activity, was also plotted and treated similarly to yield an intersection near 25 degrees C. Exposure of membrane suspensions to electromagnetic radiation, at a dose rate of 6 W/kg and at five temperatures between 23 and 27 degrees C, resulted in an activity change only for the Na+/K+ ATPase at 25 degrees C. The activity decreased by approximately 35% compared to sham-irradiated samples. A possible explanation for the unusual temperature/microwave interaction is proposed.

Experimental method for the hyperthermic treatment of cells in tissue culture: initial application to pancreatic cancer cells.

Hyperthermia is attractive as a potential adjunctive modality in the treatment of cancer, especially those cancers that are more resistant to conventional modalities. In the present study, we characterized the response of two pancreatic cancer cell lines to hyperthermia alone. In so doing, we utilized and characterized a novel exposure system that heats by 915-MHz continuous wave microwave (MW) radiation, with microprocessor control of the power input via temperature monitoring of the sample and simultaneous visualization and recording of temperature parameters. Samples, consisting of cells in 25-cm2 culture flasks with 10 ml of medium, were exposed to MWs in a stripline for 1 h at MW-induced temperatures of 37, 41.5, 42.5, 43.5, or 44.5 degrees C. The specific absorption rate was 132 W/kg for all temperatures. In addition, 37 degrees C waterbath controls were concurrently run. The colony formation assay was used to assess cytotoxicity. No significant difference was found between 37 degrees C waterbath and 37 degrees C MW controls. Significant differences in the thermosensitivity of the two cell lines were found, with the most drug-sensitive cell line showing the greatest thermosensitivity. However, hyperthermia alone was not very effective as a single cytotoxic modality in either cell line. The MW-hyperthermia-induction system provided precise, automated temperature control (+/- 0.2 degrees C), and ease of utilization and data management.

Leukocyte numbers in hemorrhaged Japanese quail after microwave irradiation in ovo

1. 1. Coturnix coturnix japonica eggs were exposed to 2.45-GHz continuous wave microwave radiation at an incident power density of 5 mW/cm 2 (and a specific rate of4mW/g) during the first 12 days of embryogeny. After hatching, hematological changes in response to an acute hemorrhage were measured in exposed and nonexposed (control) juveniles of both sexes. 2. 2. Exposure did not affect erythroid cell numbers either before or after hemorrhage. 3. 3. Exposure affected the recovery of lymphocyte and heterophil numbers after hemorrhage, but the effect was sex-limited. 4. 4. These data indicate that microwave irradiation during embryogeny in ovo affects the ability of Japanese quail to recover from an acute and voluminous hemorrhage and that these radiation effects are sex-limited and consistent with a previous report.

Leukocyte numbers during the humoral and cell-mediated immune response of Japanese quail after microwave irradiation in ovo

1. 1. Coturnix coturnix japonica eggs were exposed to 2.45-GHz continuous wave microwave radiation at an incident power density of 5mW/cm 2 (SAR = 4mW/g) during the first 12 days of embryogeny. After hatching, leukocyte differential changes were measured in response to an injection with Alectoris graeca chukar red blood cells (CRBC) and in response to a phytohemagglutinin (PHA) injection in irradiated and nonirradiated (sham) quail of both sexes. 2. 2. Microwave irradiation did not affect anti-CRBC hemagglutinin titers, PHA-evoked dermal swelling or leukocyte numbers and percentages. 3. 3. In both the irradiated and sham irradiated males, lymphocyte percentages decreased while heterophil percentages increased after CRBC or PHA injection. 4. 4. In ovo irradiation with microwaves did not alter the time course of either a humoral immune response or a cell-mediated immune response in Japanese quail.