The research OeJII.Htr itself is "with the investigation of these types, focused radiation systems and with the e.ppl: cation of the completed mass spectro: eter to the separation of isotopes of potassium and lithium il!l. The effect of thermal velocities of io·s at the hot surface of the source was calculated to be accurate. for almost the entire focal defect of the mass spectrometer. Method for solution or problems. Alternative methods of focusing. 7. Electrostatic lenses or three slits. 9. Since discovery in 1919 of isotopes of non-rodionic element. I have made many attempts, that is to say, to obtain pure specimens of individual isotones in fLs, enough for experimental nurses, without any success in the application or diiTerentia.l e1~ctrolvsis. to hydrogen and from the Hertzian diffusion ml5!bhod1 to certf". in other cases. Hertz's method is only possible for the separation of the 1-htP.st. group that can be obtained in gaseous form, and to isolate each member of a group it is necessary to use some form of it. beam of ions through slits me.kes de. queues that were excessively small; there was a need for one. mass spectrometer that would use all the ions emitted from a small area.
Such a tool was developed by Dr. develop. I will dedicate the next paf!,eS to e. d'?.sord:ption of ·certain tyoes of intense ion-:-souroes that I i:n.vesti p.:e.ted to Dr. Rumbaugh's d6perture in 1932, of methods of collection, and of examining the radioactivity of potassium with the completed mass spectrometer. to some members in Dr. Rumbeu£:h's thesis is discussed, but it is well to review the general features briefly. The boundaries of the l~.nifor-:n m~'> .rr:netic fie.ld are shown in Fig. the outline of the no .•. e-Pieees are col'llPlotc:i by -iotted lines, nnd the source assembly e.nd collecting arre.nr.:e!l!ents are also :lotted in. Shtoe actually the fiela does not have sharp bouna.aries, the field near the edges of the pole pieces was eomryuted and a correction made, which led to the reduction of the radius of the convex ~age from 28.736 om to 28.100 em and i : .Jreasing the radius of the concave edr;e .. of the pile pieces is shown by a. dotted line in Fig. 1 and in perspective in Fig. 2.
Since the width of the slit must remain the same, so that the beam will cover a large part of the slit with one piece, the emitting surface can no longer be flat, but must have a different shape, like the emitted ions. from ·nl pnrts ot' it will eventually count~· . have parallel districts. So if the electrostatic field is at any location, indicate the direction of the sravita.tionnl field at the corresponding location; point and R rr,a,~ni tu:le diff'erin~ only b.'l a. constant factor c•f'J/E, the accelerations for corresnondinr, noints in the two planes have the same directions and their absolute ma ;:o:nitudes •:will be in the rRtio. The ,naths •~11 are therefore identical and independent of the mass or charge of the ion.
The slit plate is water-cooled and supported at the ends by four invitation pillars bolted to the corners of the main cabinet, with the nata hung from metal brackets with screws that allow vertical mounting. . One of the front screws rests in 11 holes in the bottom of the source block and one slides against the flat surface, while the rear screw in a long-term flanged-bottom roof slides into this bottom surface. Thus, longitudinal expansion of the source block is allowed, while it is uselessly held against lateral movement.
The accelerator voltage is controlled by placing a 65000 ohm potentiometer across the generator leads, and a further 550000 ohm potentiometer is connected between the end and the slide tap of the first. There would be some scattering, but this is small if the mesh wire spacing is small relative to the distance between the mesh and the emitting surface. This sign assumes that there is no interpenetration of the rields through the network.
This source G gave an ion current in the slot of the pole piece of 35 microamps at 2500 volts when the source block was bright red, representing 7% of the indicated total emission. Unfortunately, the approximation on which the formula is based only applies to ions whose orbits make an angle of no more than one or two degrees with the central plane of the ions. The third beam angle of the converging ion berum in the case of the present device must be at least 20° due to mechanical problems, and the focal length can only correspond to this formula near the central plane.
FCCAL DEFECTS
It is for this reason that great care must be taken to ensure good contact in the heetin elements. The thermal velocities of 'io>'ls at the heated surface of the'.source produce the largest deviation in this type or mass-velocity.etrometer. From the kinetic theory of gases it can be shown that the component of velocity parallel to the accelerating field corresponds to a Mceleratinl.
Nevertheless, the component velocity perpendicular to the field will cause the ions to emerge from TV. 0 to their assumed direction, where vn is the normal component of the location and v0 is the reported velocity d. Therefore, the ion with velocity vn-v must have a different radius of curvature in the magnetic field than the ion for which Vn·O, if it is to reach the collection site, and will therefore be observed at some point. ~tolerating voltage that responds to a different atomic weight.
The boundary conditions require the continuity of the pnth segments and their tangents at the boundaries. ( and p. These conditions give four equations from which an equation for 9 in terms of r2 and x can be obtained. 0• In deriving this, 92 was neglected with respect to 1, making the final equation of the second degree in e.
The limiting values of x0 are determined by the length and position of the source, and r~ is obtained from the electric potential V. Now by the Me.xwell-Boltzman distribution law we have for the number·. dN of ions with a normal component of velocity between ~n and vn+ dvn. 1 that the deviation due to the th~rmA.l velocities constitutes~; !'l.J~ost the whole focl!l :tef~ct of' the mass spectroml!ter!
EMITTING MATERIALS
One sees from Fip.:. :1 that the deviation exists as a result of the high speeds; Only the entire focus of the mass spectromit lens is almost perfect. The necessity of this condition is found in the fact stated above that gas produces its main effect on the ion beam within the electric field, and in the vicinity of the heating elements near this field. Contact was made with the end of the Globar by me with a 1'1 meter piece of aluminum, which was to melt and .. perfect the connection between Globar and cup.
16-. gas is evolved at these contacts, as a result of the evaporation of the aluminum or the formation of its oxide, ~d the development of ~n. is. other types of contacts were tried, but no decrease in the . evolution of c:as could be obtained except by the use of tin with the aluminum, and tin evaporates too easily and makes holes in the cups by alloying with the iron. Th!!! e.berg of m!lterial which a"Jsorbs ges ,.,when the etppar!!l.t:us is opened, is not greater than when Globars are used, aad the robustness of the .. assembly is mueh increased, i' or Globe.rs are brittle and difficult to remove without breaking. The ioJJ. beams of the H'parated i13ot~J)es oo}lverge, at points in the focal plane of' the spectrometer whose <:iistl! llut part is: approximately proportional to the separation plane in mass numbers.
Intensity distribution. in the focal plane is then given by a curve like Fir-;. Therefore, by nlMuing a slit of .. suitable width in the '!) focal lane, any part of this i·t:~nity ou~ can be resolved. The energy carried in the cup is small and should be easily dissipated, but perhaps the cup should be cooled with liquid air so that all incident atoms are collected.
The copper rods that carry the collection cups are supported by the two insulation plates. Each plug is a double cone of red maaol with a metal. sheath between the coaes to shut off leakage current entering the measuring instrument. The foil was then treated with. The vapors from the HJI were gently heated, causing the bluish discoloration. the deposit turned white. • The amount of each isotope is approximately ··oae miorogram. In 1906 it was discovered by Campbell and Wood6 that pote.ssiu:l'!l has a radioactivity that is not susceptible to impurities from the embers of Ic'lown radioactive radiation, and Kohlhorster7 in 1928 found an "r-radiation with a hardness was smaller than that of the hard radiation of na.C. Confirmation and. The magnitude of such results8 has made it of great interest to workers in the field of nuclear physics how which isr ~on .. of !)Ot:ossium, if either, it is radioactive.
At the top left is the port-facing slot system, and to the side view is the side view and rudder, t h'!' tonal view. The wheel is turned by knob B to move the desired cup into a circle of wide slot or Geigtor eo'Jl'!ter C, which is separated from the highly discharged maia chamber by n \viJtdow of oae-mil aluminum.
CONCLUSION
0• this wheel e.re mouJtted a collecting cup a•d a cup coate.hi•g 1\Cl, the two bei:ltg separated by aluminum shi~1ds.
