Experimental holes

Experimental Hole Mobilities. The experimental values of hole mobihties in polymers are tabulated in Tables 1 and 2. The hole mobihty is field dependent. Whenever the experimental data have been fitted with equation 5, the parameters p.Q, O, and O, which give a complete description of the field dependence of the hole mobihty, are Hsted (Table 2). Otherwise, hole mobilities at selected fields are Hsted. All acronyms are defined in Figures 2 and 3. 

Figure 8. Relation of vacancy concentration in Sn1 xTE to experimental hole carrier concentration...

The mean of the experimental hole-size distribution (solid line) is larger than the mean of the distribution from LT9.0 analysis of the computer-generated spectrum (0.282 nm, dashed line). From this behavior we conclude that a part of the total discrepancy seems, however, to have a more fundamental reason. We speculate that when trapped by a larger complex hole, o-Ps can move within this hole and concentrate at that part of the hole which shows the highest openness (size and three-dimensionality). Here the localized o-Ps finds its lowest energy level within the hole. Less open parts of this complex hole may then appear underrepresented. This possible effect is not considered in molecular modeling. 

As the name implies, the reactor has been designed primarily to allow L the testing of various materials in high-intensity radiation. To accomplish this purpose about one hundred experimental holes have been provided, some going through each of the four walls Shd top and bottom of the reactor. 

Experimental hole plugs (except the 3- by. 3-in, vertical facility) and coffins would be designed by ANL. The experimental... 

The nominal diameter of the experimental holes given on DRP-64 would be used for the inside diameter of the liner. 

The shield is penetrated by about one hundred holes of various sizes Embedded.in the concrete and welded to the steel plates which act as inner and outer form plates for the concrete are all the permanent liners for the experimental holes. One of the major problems in the construction of the reactor will be the alignment of these liners. As indicated in Section 2.1.1, the top of tank section E is the only reference point available, and accuracy is essential if the HB and DB inner liners are to fit into their respective locations in thetanksectionDwall. 

Graphite Zone Liner. The graphite zone liner is the portion of the experimental hole liner which extends from the thermal shield to the reactor tank. It is a K-in.-thick aluminum tube secured at one end to the removable steel liner and supported at the other end by a pilot ring on the reactor tank. The liner is removable and is not permanently secured to the reactor tank because this tank is designed as a removable component. 

Removable Concrete Shield. To fill the void space in the large ateel liner outside the radiation door, a steel-encased concrete cylinder is provided for necessary shielding. Eccentrically located in the concrete billet is a steel-encased cylindrical hole of approximately 10 in. I.D. which forms a portion of the experimental hole. Removal of this shield permits access to the radiation door. 

There shall be no blind water connections which wil have to be made np after insertion within the reactor strnctnre, and the complete cooling circuit for the ping shall be arranged to allow testing for leaks prior to insertion in the experimental hole. 

In regard to insertion and withdrawal, the round portion of the experimental hole has an adapter or tray which enables the square plug to pass... 

S Other orisemtal Bzperi mentel ud inetrmment Holes. In addition to the main experimental holes described in the previous sections, there are six more horizontal through holes.. Four of these, HG-l through HG-4, are for experimental use the other two, HI-2 and HI-3, are for reactor control instruments. 

Experimental Holes. The locations of holes HG-l through HG-4 can be seen in Figs. 3.A and C. HG-l and H6-2 go through the full length of the east graphite wail while HG-3 and -HG-4 penetrate the west wall. The first two holes are 8 in. in diameter, the latter two Ain. in diameter through the graphite. 

Coffins. Whenever the occasion arises to insert or retract a plug, a heavy lead shielded coffin is accurately aligned at the chosen experimental facility. After proper alignment, the plug is withdrawn from or inserted into the beam hole. The coffin requirements for the MTR experimental holes can be satisfied by three coffins, each coffin to take care of one of the following three groups of holes ... 

The other two experimental holes provided in the reactor are intended for y-ray experiments. These holes, GT- 1 and GT-2, are stainless steel thimbles, 6 in. in I.D. projecting into the exit water lines where the N activity will be high. 

In addition to the above experimental holes, twelve 2-in.-I.D. holes are provided in the concrete. These holes, designated VC-1 through 9 and VC-11 through 13, penetrate the south wall of the biological shield to elevation 92 ft. Their location is indicated in Fig. 3.E around the south instrument cubicle (to the right of GM-1) and between the cubicle and the outer edge of the reactor top. It is expected that these holes will.be useful for thermocouples or for shielding measurements. 

Sullivan, T. E., Requirements and Basis of Design - Experimental Hole Piugs. ANL-ABS-9, October 5. 1949. 

The. added heat fluX per. experimental hole is about 0./03A /A bw, where A is the cross-sectionaT area of the hole, and A is the.distance from the core surface to the. face, of.the hole opposite the core surface, provided A is much smaller than A. For the 6-ih. hole A 40 cm, the total heat flux is about 0.6 kw or 3.5 watts/cm. Tbe pile y-ray heat flux at 40 cm in the absence of a hole is 3.5 watts/cm hence the hole increases the load due to the y-ray heqt by a factor of 2, or the total heat flux increases from 4.6 watts/cm (see Fig. 4.5.A) to 4.6 + 3.5 8.1 watts/cm -. --... 

Spatial distri But ions of thermal, indium resonance, and fast (E > 1 Mev) neutron flux in the core and in the reflector, particularly the distributions of thermal and indium resonance neutrons in the experimental holes. 

Effect of Experimental Holes in the High-flux Ucactor Critical Assemblies... 

Table A3.C contains a summary of the total cost in Ah/h for two alternate provisions for experimental holes. This table shows the change in Ab/k that would be expected if the holes in these two cases should be filled with water. An estimate of the cost of the holes in terms of critical mass can, be obtained by use of the empirical relation Atf/lf =4.5 Afc/h. However, this relation leads to a reasonably accurate result only in the case of fuel AH added to the periphery of a cylindrical core. In the case of a rectangular geometry, the cost in critical mass (All) corresponding to a given Ak will depend strongly on the statistical weight of the position at which the additional fuel is added, and the figure obtained from 4.5 Ak/k is a reasonable approximation only for positions of average statistical weight.

The spatial distributions of thermal and epithermal neutron flux in the 2.94-kg pile, the 3.95-kg pile, and in the various experimental holes of the mock-up assembly, as indicated in the listing below, were measured. These measurements were made with indium foils, used alternately bare and cadmium covered, as described previously. A calibration. of foils in the standard (sigma)reactor indicated that the absolute flux (nv) is obtained from the measured saturated activities, shown in the attached figures by the following relations, ... 

Figures A3.F, G, H These show the neutron distributions along the axes of the. various experimental holes which were planned for the high-fluxreactor. These measurements were made with all seven 6-in. holes (or equivalent) in the reflector. 

Figure A3.I The fast-neutron flux ( > 1 Mev) and the indium resonance flux, measured along a line midway between two of the large experimental holes that extend through the reflector. 

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