Radiation receiver

The thermal radiation received from the fireball on a target is given by equation 9.1-31, where Q is the radiation received by a black body target (kW/m ) r is the atmospheric transmissivity (dimensionless), E = surface emitted flux in kW/m", and f is a dimensionless view factor. 

These coefficients must be multiplied by the density of air and tissue, respectively. Figure 15.7.2-1 depicts a radiation fallout field. Let C be the curie activity/m. The radiation into a unit area receptor at z = 1 m above the ground. The area is emitting C r dr d0 gammas/s. These are attenuated in the air as exp(-p, R) and geometrically as l/(4 7t R). The radiation received by the receptor is given by equation 15.7.2-1 which becomes 15.7.2-2 by a change of... 

Suppose two objects are in a hollow (Fig. 4.30) object A, which is black, and object B, which is gray (a body that does not absorb all the incoming radiation). The energy and mass are in balance when the temperatures of A, B, and C are equal. In the balanced state the radiation emitted by the bodies is equal to the radiation received. 

E = emissive power of emitting surface 2 = incident radiation receiving surface... 

Application of the reciprocity relation A F 2 = 2 21) allows the fraction of radiation received by the target (apart from atmospheric attenuation and emissivity) to be expressed as... 

The total radiation received by an object also depends on the fireball s position relative to the object (i.e., the view factor) and radiation adsorption by the atmosphere. 

Alternative Enq>irical Equation for Radiation Received by an Object... 

The heat radiation received by an object depends on the flame s emissive power, the flame s orientation with respect to the object, and atmospheric attenuation, that is... 

The thermal radiation received by an object in the environment may now be computed if it is assumed that the flame appears as a flat plane, 33 m high, which propagates at a constant speed of 4.6 m/s during the full period of flame propagation (100/4.6 = 21.7 s). During this period, flame width varies from 0 to 100 m and back, according to Figure 8.1b ... 

For a receptor not normal to the fireball, radiation received can be calculated based on the solid flame model as follows ... 

The point-source model can also be used to calculate the radiation received by a receptor at some distance from the fireball center. Hymes (1983) presents a fireball-specific formulation of the point-source model developed from the generalized... 

Estimate the radiation received at a receptor. With an attenuation factor of 1, the radiation received by a vertical receptor at a distance X from the tank can be calculated from ... 

Alternative reproach point-source model. Another method of calculating the radiation received by an object relatively distant from the fireball is to use the point-source model. From this approach, the peak thermal input at distance L from the center of the fireball is... 

I Estimate the thermal impact. The thermal impact of a fireball on humans is a function of both the radiation received and the fireball duration. The impact can be estimated from Figure 9.1. In this case, the fireball duration is estimated to be about 10 seconds, while the estimated radiation is presented in Table 9.1. Based on these data the impact to unprotected humans can be estimated and is shown in Table 9.2. Note that while there is a difference of about 15% in the radiation levels estimated from the two models, the estimated impact on humans is essentially the same. 

View factor The ratio of the incident radiation received by a surface to the emissive power from the emitting surface per unit area. 

Henrich and WolP have studied the formation of Mo(CO)5 by catching Mo and Mo recoils in Cr(CO)g. The Molybdenum isotopes were produced in several different reactions, so that the recoil energy varied over a wide range. It was found that the yields of Mo(CO)g with the two isotopes differed from each other, but varied only slightly as a function of initial recoil energy. These authors were also able to show that the isotope effect of about 8% is nearly insensitive to radiation received by the sample (and catcher) during the bombardment. They argued that there remains only one possible cause of this isotope effect, that is, differences in the de-excitation schemes of the product nuclei. 

Electron spin resonance (ESR) measures the trapped electron population in a lattice, which is directly related to the amount of ionizing radiation received by the sample since its formation. The total radiation dose received by the sample is estimated from the ESR... 

Figure 9. UV emission spectra of various molecules in the high-frequency discharge (2). I( ) = intensity, measured on radiation receiver, K = wavelength. (-----------------) OH(H.O) ( ) O, (— — j N, tenfold reduced...

SC-40 Biological Aspects of Radiation Protection Criteria SC-41 Radiation Resulting from Nuclear Power Generation SC-42 Industrial Applications of X Rays and Sealed Sources SC-44 Radiation Associated with Medical Examinations SC-45 Radiation Received by Radiation Employees SC-46 Operational Radiation Safety... 

Folsom, T.R. and J.H. Harley. 1957. Comparisons of some natural radiations received by selected organisms. Pages 28-33 in National Academy of Sciences. The Effects of Atomic Radiation on Oceanography and Fisheries. Publ. No. 551, Natl. Acad. Sci.-Natl. Res. Coun., Washington, D.C. 

If the object is the wall itself, then Equation (11.13) simplifies to the rate of radiation received by the wall as... 

Dosimetry is an autoradiographic technique to measure the total dose of radiation received by a worker ov -r a period of time. 

Insolation Solar radiation received at Earth s surface. 

Fig. 1. This example of a cumulative dose volume histogram (DVH) exemplifies the manner in which three dimensional treatment planning allows the radiation oncologist to ensure that the tumor receives the planned dose while limiting the dose of radiation received by the normal structures. In this example 100% of the gross tumor volume (GTV) receives 70 Gy whereas the dose received by any length of the spinal cord is less than 45 Gy.

In the alternative way of treating A, a small fraction of the beaker s contents is continuously removed, irradiated, and returned to the beaker. Although the total absorption rate is the same in the two cases, the intensity of radiation received by the removed fluid is greater, and it could well be, if the flow rate is not too high, that the fluid being irradiated reacts essentially to completion. In this case, then, A is removed and S is returned to the beaker. So, as time passes the concentration of A slowly decreases in the beaker, S rises, while R is absent. This progressive change is shown in Fig. 8.2. 

With this apparatus (Ref 2) the temperature in the flame brush could be determined in the range 600-3500° K. A PbS photoresistor was used as the infrared radiation receiver it has significant sensitivity and low visual persistence... 

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