A study has been made of the time and temperature required to anneal Teflon and Fluorothene. It has been found that, by proper annealing, the strains my be removed and cold-flow prevented. The disk stopcocks prepared with annealed plastics have not developed leaks on standing. A description is given of the modified slug-dissolver heating unit which has been installed in the Bismuth-II Process Line. Work has been continued on the absorption spectra of bismuth in hydrochloric acid solutions. Two methods have been described for the interpretation of absorption spectra data. The transmission curve of the Evelyn colorimeter filters have been measured on the Cary recording spectrophotometer. The resulting curves should aid in the selection of the proper filter for a given calorimetric analyses. A brief outline for the proposed method of decontaminating platinum has been presented.

The supersonic method of cleaning glassware is an outgrowth of the fact that it has been heretofore impossible to manually clean ground glass and quartz joints because the activity became lodged in the small pores of the ground surfaces. It has been theorized that the nature of the forces binding polonium to the glass is similar to that of the chemical bond but are less intense. The problem then becomes one of finding a force greater than this binding energy, capable of freeing the activity from the glass. This has been accomplished by using frequencies of 100 cycles to 20 kc at a power output from 2 to 20 watts, passing through a citric acid solution (pH-2) into which the contaminated article is placed. The optimum results, using a tank with the dimensions 7 in. {times} 7 in. {times} 7 in. and 3 liters of solution, has been found at 200 cycles or harmonics of 200 cycles. Citric acid was used because of the fact that it forms a soluble complex with polonium. The frequencies used have been kept within the sonic range until enough data has been obtained and correlated to warrant the design and construction of more costly …

With the completion of tests of the prototype cathode-follower, it was decided to produce three more models. These have been constructed and pass the same pulse as that of the prototype. Drawings are being made of these units. By the time these units had been completed, the amplifier of the scaler was modified so that its frequency response was essentially flat up to 4.5 megacycles. Using this amplifier and the cathode-follower, a study of the pulse shapes was made and four different pulse shapes were found to be obtainable. A band pass network between the B-wall tube and the input of the cathode-follower provided a very substantial improvement over the shunt peaking network with a band pass of 1.8 to 6.5 megacycles and provided clean, uniform pulses. Plans are being made to experiment with a filter of narrower band pass, which, if satisfactory, will produce greater amplitude. When the final band pass has been determined, a combination of shunt peaking and band pass networks should provide a net gain of 30% in amplitude. The result of this research is to provide an immediate improvement in resolution loss and a possibility of realizing a still lower minimum resolving time when the …

The attenuation of electro-statically and electro-magnetically shielded rooms in the ``E,`` ``R,`` ``I,`` and ``T`` Buildings was measured so that corrective measure could be taken if the attenuation was found to be low. If remedial measures could not be taken, the shortcomings of the rooms would be known. Also, the men making the measurements should oversee construction and correct errors at the time. The work was performed by measuring the attenuation at spot frequencies over the range of from 150 kilocycles to 1280 megacycles with suitable equipment mounted in small rubber-tried trucks. The attenuation was determined by ``before and after`` shielding and/or ``door open and door closed`` measurements after installation of copper shielding. In general, attenuation in the frequency range of approximately 10 to 150 mc. was good and was of the order expected. At frequencies in the range of 150 mc. to 1280 mc., the attenuation curve was more erratic; that is, at certain frequencies a severe loss of attenuation was noted, while at others, the attenuation was very good. This was mainly due to poor or faulty seals around doors and pass windows. These poor seals existed in the ``T,`` ``E,`` and ``I`` Buildings because the doors were …

A design is proposed for a removable drainage grill and trap for floor drains in radioactive risk areas. One simple element provides free liquid run off, an air and fume barrier, and ready access for cleaning or replacement in event of contamination. Application may be made to existing and future untrapped drains.

This document is a March 1949 Ad Interim Report on the development of a high-speed, low-sensitivity calorimeter at the Mound Laboratory. This calorimeter is a zero-compensating, thermocouple, twin type. The outside diameter of the aluminum tubing was machined for a slip fit into the glass test tube. Prior to assembling in the test tube, an aluminum plug was pressed in it midway from the ends. A groove was also milled on the outside down to the plug, and a copper-constantan thermocouple was secured in the groove after assembly. A single layer of aluminum foil was used to reduce radiation effects, and stray air currents were excluded with a cotton plug. The two arms of the calorimeter were placed in a three-liter beaker filled with water. The constantan leads of the two thermocouples were soldered together to make them compensating. The copper leads were connected to a L & N potentiometer, and a L & N galvanometer was also used. The potentiometer-galvanometer circuit was so connected that before each reading of the EMF of the thermocouples, the thermal EMF in the circuit could be accounted for. The galvanometer was then mounted on a heavy brass plate. The data show that when …

The following items of equipment have been completed: Two Scaler Multipliers, EO-18 and EO-338, undergoing test and adjustment. One Thyratron Heater Control for Scioto Laboratory. One Pilot model switch box for Group 16 hoods at Scioto Laboratory. One Pilot model patch box used as auxiliary to the present switch boxes. Installation of electronic equipment and sorting and cataloguing of stock at Scioto Laboratory has been started. The Y Section induction heaters have been installed electrically. With the present setup in the WD Building, it has been necessary to recycle all the solution which passes through the pH chamber on the clariflocculators. Sufficient tests have been run on the Berkeley Decimal scaler to indicate that, by using a pre-emplifier, it will be a satisfactory replacement for the scaler multiplier. Reworking of B-wall tubes has been held up pending the delivery of neon gas. Further investigations have been made on the frequency compensated constant voltage Sola transformers. Three automatic potential controllers have been modified in accordance with investigations of Group 10. The program of preventative maintenance on automatic potential controllers has resulted in a marked reduction of service calls and down-time for the operating group.

Prospectus` of Band Pass Amplifiers for Proportional Counters and Instrumentation for the Study of the Electrodeposition Potential of Radioactive Elements have been submitted for review and approval. An error was found in calculations for the band pass amplifier discussed in Group 9 of the Electronics Progress Report,MLM-306, March 1--31, 1949, on the Cathode-Follower Probe. New calculations have been made and a band pass filter constructed to match the new values. Work on the cathode-follower circuit for coupling a Boron-wall tube to its linear amplifier indicated that the limit to the sharpness of a pulse which could be achieved was possibly caused by poor amplitude versus frequency response of the linear amplifier. To check this theory, modifications were made on an existing scaler which resulted in a frequency response flat up to 4.5 megacycles. Plans are being made to improve the amplitude versus frequency of the higher frequencies. The response curve shows a slightly rising characteristic at 4.5 megacycles and an attenuation at 7 megacycles. Construction of the rf generator has been resumed in an effort to deliver the finished product to Group 4 by approximately May 6, 1949. The meter circuit will measure relative rf output voltage instead of absolute …

The purpose of this report is to review the characteristics of particulate contamination which set it apart from the other phases of the radiation control program and make it necessary to apply to it different concepts, analytical procedures, and control measures. The program is treated as one in the appraisal and control of dusts and fumes. The fact that the material is radioactive introduces certain new details, but this does not make the problem basically different from others in the field of industrial dust control.

The assay technique is discussed in detail. The results of three purity determinations are: 94.92 per cent, 100.50 per cent, and 106.9 per cent. The errors present in each determination are stated. The inherent dangers in the present procedure are pointed out, and an improved method is outlined.

This document details the activities of the biological research program conducted by the Mound Laboratory during the first quarter of 1949.

The cloud chamber is a means of observing the path of ionizing radiation. It does not reveal the radiation directly, but gives a visible trail of the path along which the radiation has traveled. The trail is formed by vapor condensing upon pairs of ions remaining after an ionizing particle has passed through the medium. The mutual interaction among rays, atoms, nuclei, and particles, can be studied and measured with the aid of vapor trails. Measurements of changes in direction and range as recorded on the photographs may be interpreted in terms of changes in momentum and energy of the particles in these reactions. To obtain a precision measurement is difficult with a cloud chamber. The dependence of the apparatus upon a sudden gas expansion is certain to create distortions resulting from turbulence. Furthermore, since any radiation is subject to variations, precision measurements can be obtained only be the collection of numerous observations for statistical analysis. This document details the design, operation, and limitations of cloud chambers.

The principal object of this report is to record results of tests made on equipment installed in Room 232 of ``T`` Building and used to prepare bismuth powder for process operations. Another object is to establish the most favorable operating conditions for the equipment and to prepare operating instructions therefor.

Prior to April 1948 the generally accepted method of reducing the radioactive contamination of metal tools and laboratory apparatus was a series of rinses in aqua regia or various other concentrated acids. This method proved unsatisfactory for three reasons. (A) It was not a dependable method of removing activity. (B) It had a delecterious effect on tools in that it caused serious pitting, which resulted in weakened parts, and exposed a bare metal that was subject to very rapid corrosion. (C) Tools and apparatus once cleaned by this method could not readily be cleaned a second time. With the aforementioned limitations in mind, it became obvious that a new method was required. After considerable investigation into a electrochemical processes the present method was developed. Essentially, the new method is an electropolish bath to remove the activity lodged in the pores of the metal, and a ``follow-up`` chrome plate bath to render the surface impassive to corrosion.

Several bismuth compounds have been submitted by E. Orban for examination by x-ray diffraction. The sample of polonium in contact with platinum mentioned in the May progress report was received and identified tentatively from its x-ray diffraction pattern as PtPo{sub 2}. Calibration of the Perkin-Elmer infrared spectrophotometer has been completed and a preliminary study of the infrared absorption of NiCO{sub 4} made. Data showing the spectral purity obtainable on three ultraviolet-visible spectrophotometers have been completed. The emission spectrum of a sample of volatile impurity from the operations process has been obtained.

This document details gamma scale chemistry activities at Mound Laboratory during the month of May 1949.

The objectives in producing neutron sources are to produce uniform products of as high efficiencies as possible from the neutron yielding elements and to do this in the safest manner. The purpose of the present work was to improve the methods of preparing sources and at the same time increase the types of sources available. Lithium, sodium, and their compounds were chosen because the neutron fluxes and energies are low, thus making the experimental work less hazardous to the operator. Also, the elements are quite reactive, so that techniques which are successful with them can be easily adapted to other materials. Solvents for polonium, ways of mixing polonium and target, neutron yields, reproducibility, decay of the sources, means of recovering polonium, and materials for containers, were investigated.

The constant temperature bath is in operation. A ballistic type instability was detected in the calorimeter circuits and corrected by grounding the bath. Calorimeters 37, 39, 40, and 43 have been installed are now being run. Calorimeter 40 was found to be unstable, and is to be disassembled and examined for the trouble. Calorimeter 46 was finished and placed in operation. Construction details are discussed. Six Logac samples were run in Calorimeter 38. Tests of this calorimeter are in Table 1. Comparison of Calorimeter 38 in a water bath and in an ice bath is shown in Table 2. Good results were obtained for such a drastic change in environment. Calorimeter 38 was turned over to Calorimetric Assay marking the end of the tests of this particular microcalorimeter. Calorimeter 44 was completed and installed in the ice bath. Table 4 shows the results of tests. The zero bridge potential is small and is very stable compared to Calorimeter 38. The comparison of the values with those from Calorimetric Assay is summarized in Table 3. The characteristics of Calorimeter 44 are shown in Table 5. Construction details are given for the platinum-manganin bridge-type thermometer. An instrument was needed that could be …

Apparatus for measuring the resistivity of polonium is described. This equipment has been built and tested. No resistivity measurements were made, however, because the method of determining the purity of the sample has not been perfected.

Experimental use of sodium radiophosphate (P32)in treatment of polycythemia is described. Treatment history is 66 patients treated with P32 alone, 32 patients treated with P32 followed within 4 months by venesections, 21 patients treated with P32 followed more than 4 months later by venesections, 6 patients treated exclusively by venesections, and 9 patients treated and followed elsewhere.

Considerable study has been given to the problem of a cathode-follower coupling circuit for matching a B-wall tube to a properly terminated coaxial cable. A matched circuit makes it possible to obtain faster counting rates independent of practical cable lengths. A breadboard circuit has been built and first results indicate that a two millivolt signal at the input of the cathode-follower will operate the Model 162 Instrument Development Laboratory Scaling Unit when adjusted for maximum gain. This is comparable to the voltage available when the B-wall tube is coupled to its amplifier through a coaxial cable. Shielded room measurements have been completed in the ``R`` Building. One log-amplifier (EL-257) was delivered to group 32, one scaler-multiplier (EL-252) to group 34, one four-input GM mixer (EL-247 to Group 24, and the plating control regulation checker (EL-258) plus the portable pulse generator (EL-261) to Group 12. The scaler-multiplier (EL-253)is 20 per cent complete and the motor-driven slide wire and the four-input gamma mixer (EL-262) are 95 per cent complete. The manufacturing specifications for plating controls and the instruction book for the portable pulse generator (EL-2561) have been submitted for duplication and should be completed by January 31, 1949. The two (2) 6 …

The Purpose of this manual is to describe preparation of bismuth powder for use in process operations. Bismuth powder is to be prepared in Room 232 of ``T`` Building where all necessary apparatus is installed.

This document is a March 1949 Ad Interim Report from the Mound Laboratory on the solution chemistry of polonium. A consideration of the valences of the elements of the Group VI-A would indicate that the oxidation states of -2, 2, 4, and 6 might be expected for polonium. From the decrease in stability of the hydrides of these elements with increase in atomic number, one would expect that the compound H{sub 2} Po would be very unstable and that the oxidation state of -2 would not occur in solution. Furthermore, the stability of the oxidation state +6 as well as the stability of the highest oxidation state of a given element decreases as the atomic number increases in Group VI-A and Period VI respectively. For these reasons, the oxidation state +6 for polonium would be expected to occur only in a strongly oxidizing medium. The +4 state would be expected to be stable. The work discussed herein indicates that polonium exists as PoO{sup ++} in a nonoxidizing or reducing medium.

The attached material balance flowsheet for the proposed Redox Production plant is based on the two chemical flowsheets submitted by R.B. Richards of the Technical Division in HW 13,320 (INDC-3130) and HW 13,452 (INDC 3176). Production rates for the plant have been assumed as 2.5 short tone U per day (including a maximum of 0.75 short tons of U from stored Bi PO{sub 4} waste) and 19 kg. Pu per month (633 gms/day) as established by the Redox Committee. The flowsheets for preparation of solvent extraction feed from Bi PO{sub 4} waste, as well as the waste treatment systems will be covered in a future document.