U.S. patent number 3,846,636 [Application Number 05/176,584] was granted by the patent office on 1974-11-05 for method and means for utilizing accelerated neutral particles.
This patent grant is currently assigned to Reactor Accelerator Development International, Inc.. Invention is credited to Monita May Thorp Lank, Psych Lank, Phyllis Joan Zehr.
United States Patent |
3,846,636 |
Zehr , et al. |
November 5, 1974 |
METHOD AND MEANS FOR UTILIZING ACCELERATED NEUTRAL PARTICLES
Abstract
The invention resides in the utilization of radiant energy by
bringing together accelerated positive ions and accelerated
electrons or accelerated negative ions to produce accelerated
neutral particles the energy of which may then be converted to heat
on bombardment of particles of an appropriate reactant, or utilized
in other ways as in neutral particle radiography.
Inventors: |
Zehr; Phyllis Joan (Claymont,
DE), Lank; Monita May Thorp (Media, PA), Lank; Psych
(Media, PA) |
Assignee: |
Reactor Accelerator Development
International, Inc. (Claymont, DE)
|
Family
ID: |
22644951 |
Appl.
No.: |
05/176,584 |
Filed: |
August 31, 1971 |
Current U.S.
Class: |
376/156; 250/251;
376/127; 976/DIG.419; 376/107; 376/199; 976/DIG.437 |
Current CPC
Class: |
G21K
1/14 (20130101); G21H 3/00 (20130101) |
Current International
Class: |
G21K
1/00 (20060101); G21K 1/14 (20060101); G21H
3/00 (20060101); G21g 003/00 () |
Field of
Search: |
;250/84,84.5,41.3,499,501,502 ;313/61 ;176/1 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lawrence; James W.
Assistant Examiner: Dixon; Harold A.
Attorney, Agent or Firm: Walton; W. Wyclif
Claims
We claim:
1. The method of producing a low to high velocity neutral particle
beam which comprises generating and accelerating to a high velocity
a substantially rectilinear stream of positively charged particles,
generating and accelerating to a high velocity a substantially
rectilinear stream of negatively charged particles, directing them
along substantially parallel but converging paths and into a single
beam whereby the charges carried by the positively charged
particles are neutralized by the charges carried by the negatively
charged particles and combined in a low to high high velocity
neutral particle beam.
2. A method in accordance with claim 1 in which said streams of
charged particles are synchronously scanned before converging into
a scanning neutral particle beam.
3. A method in accordance with claim 1 wherein the accelerated beam
of said neutral reactant particles projects into a mass of
dispersed relatively static reactant particles which on bombardment
by said neutral particles release energy in the form of heat and
radiation.
4. A method in accordance with claim 3 wherein the beam of neutral
reactant particles projecting into the mass of dispersed relatively
static reactant particles is flooded by electrons from an electron
gun provided with an appropriate scanning device to encompass the
projected beam of neutralized reactant particles within the mass of
dispersed relatively static particles.
5. The method as defined in claim 3 wherein said relatively static
reactant particles are dispersed in a substantially evacuated
chamber and the chamber walls are engaged by a fluid heat exchange
medium.
6. The method as defined in claim 3 wherein said relatively static
reactant particles are dispersed in a solid mass of a metal
transparent to the passage of the accelerated neutral reactant
particle beam.
7. A method in accordance with claim 1 in which an accelerated beam
is interreacted with the particles in another high velocity neutral
particle beam produced in accordance with said method.
8. The method as defined in claim 1 wherein the scanning beam of
said neutral particles is directed toward a sensitized surface
adapted to be excited by impingement thereon of said particles and
a non--homogeneous solid body to be examined radiographically is
interposed in said path between the source of said particles and
said sensitized surface.
9. Apparatus for projecting along a substantially rectilinear path
a directionally variable continuous beam of high velocity neutral
reactant particles which comprises disposing adjacent each other
means for generating positively charged particles and means for
generating negatively charged particles, each such generating means
including particle accelerating means, and means for directing the
accelerated charged particles in converging streams within a
substantially evacuated chamber whereby without appreciable
deceleration said positively charged particles and said negatively
charged particles commingle and the positive charges of the
positively charged particles are neutralized by the negative
charges of said negatively charged particles to thereby project
from said apparatus a beam of accelerated neutral reactant
particles.
10. In combination with the apparatus defined in claim 9 a pair of
continuous synchronous charged particle scanning devices interposed
in the path of each of said converging streams for translating
transversely of the general direction of the stream the particles
therein.
11. In combination with the apparatus defined in claim 9 means for
interposing in the path of said neutral particle beam a mass of
relatively static reactant particles of a reactant, and means
defining a passage for a fluid heat exchange medium in heat
exchanging relation with said first mentioned means.
12. In combination with the apparatus defined in claim 9, means
defining a substantially evacuated chamber containing relatively
static reactant particles of a reactant, means for directing into
said chamber said beam of accelerated neutral particles and heat
exchange means associated with said chamber defining means
providing a passage for a fluid heat exchange medium.
13. In combination with the apparatus defined in claim 9, detecting
means excitable by impact of said accelerated neutral particles
disposed in the path of said particles and means for supporting in
said path between said detecting means and said apparatus a solid
body non-uniformly transparent to said accelerated particles.
14. Apparatus as defined in claim 9 including means for interposing
in the path of said accelerated neutral reactant particles a mass
of relatively static particles of a reactant, means in heat
exchanging relation with said first mentioned means defining a
passage for a fluid heat exchange medium and at least one
additional apparatus as defined in claim 9 disposed to project a
stream of accelerated neutral reactant particles into said mass of
relatively static reactant particles in a direction different from
the direction of projection of accelerated neutral particles
thereinto from said first mentioned apparatus.
Description
BACKGROUND OF THE INVENTION
1. Field of Invention:
The invention relates to accelerated particles of radiant energy
having opposite electrical potential relative to each other which
are brought together to form a united particle beam in which the
particles mutually neutralize each other as to potential without
deceleration for useful purposes such as generation of heat by
bombardment of an appropriate static and/or accelerated neutral
reactant in an adjacent novel reaction chamber, in neutral particle
radiography or the like.
2. Description of Prior Art
Radiant energy particle generators are well known and various types
of apparatus have been developed for accelerating such particles to
a desired velocity in a predetermined direction as in U.S. Pat.
Nos. 2,735,019, 3,287,592, and 3,393,316, such particles having
electric charges either positive or negative, depending on the
nature and operation of the particle generators employed, and so
far as we are informed these and similar particle generators and
accelerators have been used as tools in nuclear physics research
but there has not been suggested means for converting the energies
derived from reactions of neutralized particles to states useful in
performing work, such as heat for generation of electricity, the
energy of the particles having heretofore been dissipated in other
ways and its potential availability for useful purposes has been
lost.
SUMMARY OF THE INVENTION
The invention resides primarily in the provision of a method of and
means for bringing together in a common accelerator chamber
converging synchronously scanning streams of accelerated particles
of opposite potential and without appreciable deceleration allowing
each respective stream to neutralize the electrical potential of
the other and form a resultant neutral particle stream which is
then directed out of the chamber in a scanning beam of neutral
reactant particles for utilization in the performance of desired
functions, such as the generation of heat by bombardment of an
appropriate reactant by the neutral particle beam, radiographic
examination or for other purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a diagrammatic longitudinal section of particle
generators, accelerators, and synchronous charged particle beam
spreading devices utilized to produce a unique variable directional
beam of neutralized reactant particles in combination and
association in accordance with the invention with a novel reaction
chamber embodying heat generating and recovery means.
FIG. 2 is a diagrammatic perspective view of the apparatus
illustrated in FIG. 1.
FIG. 3 is a diagrammatic illustration of a modified arrangement
where in two neutral particle generator and accelerator assemblies
or units are associated with a single reaction chamber.
FIG. 4 represents the employment of a still large number of neutral
particle generator and accelerator units associated with a circular
reaction chamber, or it may be deemed to represent an even larger
number of such assemblies associated with a spherical reaction
chamber constructed in accordance with the same principles.
FIG. 5 diagrammatically illustrates the disposition of a plurality
of the neutral particle accelerator assemblies arranged in opposed
ranks along the sides of an elongated rectangular reaction
chamber.
FIG. 6 is a diagrammatic representation of the manner in which one
of our neutral particle generator and accelerator assemblies may be
utilized for neutral particle radiography examinations.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to FIGS. 1 and 2 of the drawings
the apparatus shown therein comprises an accelerator chamber 1
which may be substantially pyramidal, having a removable access
opening closure 2 secured thereto in sealed relation through the
utilization of bolts or cap screws 3. Connected through the wall of
the chamber to its interior through pipe 4 is a vacuum roughing
pump 5 and a vacuum diffusion pump 6 by operation of which the
interior of the chamber may be evacuated to a pressure of the order
of 10.sup.-.sup.6 mm. (Hg), a valve 7 controlling the pipe while a
gauge 8 connected therewith permits the pressure in the chamber to
be ascertained.
At its apex the accelerator chamber has an opening sealed by a
suitable window 10 which is transparent to accelerated neutral
radiant energy particles when directed toward it in a high velocity
beam, iron being preferably used for the window material when
isotopes of hydrogen are the source of accelerated neutral
particles. Contained within the chamber is a positive ion generator
and accelerator 12 which may be of any usual or well known
character capable of generating ions and accelerating them to high
velocity in a stream directed generally toward the window 10, while
generally paralleling the accelerator 12 is a generator and
accelerator unit 14 capable of producing and accelerating in a
stream of like velocity either electrons, or if preferred negative
ions.
Connected with the positive ion generator and accelerator unit 12
through a pipe 15 from externally of the accelerator chamber is a
source of reactant material represented by tank 16 which is
admitted to the unit under control of a valve 17, while a similar
arrangement of a pipe 18, tank 19 and valve 20 afford means for
introducing a source of negative ions to the generator and
accelerator unit 14 or an electron generator and accelerator may be
substituted for these elements if electrons are to be used as the
negative particles. A showing of electrical connections with these
units is omitted from the drawings as superfluous, such connections
being well known in the art and hence not requiring
illustration.
A partition 25 of insulating material is interposed between the
positive and negative ion generator and accelerator units 12 and 14
to maintain the electrical and radiational integrity of each, while
adjacent their respective exit ports for the accelerated particle
streams are synchronous scanning devices 26, 27 of known character,
which operate in a novel manner electrically and magnetically in
synchronism upon the ionized particle streams to direct the latter
within predetermined courses constantly translatable in all
directions transversely of the direction of the streams and
preferably generally converging in the direction of window 10 to
meet in the vicinity of some intermediate point such as the point
P. The potential carried by the positive ions generated in unit 12
is thereupon neutralized by the potential of the electrons or
negative ions generated in unit 14 and the resulting neutral
particles, still travelling at high velocity, then pass through
window 10, in the apparatus illustrated in FIGS. 1 and 2, to a
novel reaction chamber 30 now to be more fully described.
This reaction chamber, like the neutral particle accelerator
chamber just described, is designed to be evacuated to a like low
pressure and it is constructed accordingly, preferably of highly
corrosion resistant materials, and of course, with all joints and
connections fully sealed. It comprises a cylindrical inner casing
31 into one end of which the neutral particle acelerator housing
projects, window 10 thus giving into the interior of casing 31.
Connected with the latter also, through a pipe 32 is a mechanical
vacuum roughing pump 33, a vacuum diffusion pump 34 for increasing
the vacuum beyond the capacity of pump 33 and a valve 35,
controlling the passage through the pipe, a pressure gauge 36
connected with the pipe affording reading of the pressure in the
casing which, as indicated, should be of the order of
10.sup.-.sup.6 mm. (Hg). Also connected with the interior of casing
31 is a pipe 37 controlled by a valve 38 and fed by a storage
recepticle 39 normally containing a supply of suitable, preferably
gaseous or volatile, reactant, such as, for example molecular
hydrogen when the material employed for generating positive ions in
unit 12 is also an isotope of hydrogen.
Surrounding and completely containing the casing 31 is a jacket 40
spaced from the outer wall of the casing to permit free flow in
heat exchange relation with the casing of a liquid or a gaseous
heat absorbing medium admitted through a pipe 41 leading into the
jacket for discharge therefrom through an exit pipe 42 from which
it may be directed through appropriate conduits, (not shown) to
other apparatus such as turbines or the like for converting heat to
electrical energy or for other useful purpose.
To minimize wasteful dissipation of heat from the jacket 40 it is
preferably enclosed in a heat insulating and radiant energy
absorbing shield 45 confined within an outer covering 46 and the
whole apparatus is supported from a floor surface on appropriately
positioned legs 48.
All parts of the apparatus which confine or encounter radiant
energy particles are preferably made of materials relatively inert
thereto such as carbon steel, high strength or corrosion resistant
steel or other metal or alloy, with the parts except for the bolted
access panel 2 preferably of welded and tested construction to
minimize leakage under the high vacuum conditions maintained in the
accelerator and reaction chambers.
Performance of the preferred embodiment of the invention just
described will be apparent to those skilled in the art from what
has been herein disclosed, and the specific series of steps now to
be set forth will be recognized as merely examples of procedures
which may be employed in the practical application of our
invention.
Thus, there may be supplied to the positive ion generator 12 from
the storage tank 16 gaseous hydrogen in the form of deuterium
(D.sub.2), while the negative particle generator 14 may be selected
and arranged to project electrons (e.sup.-). The velocity of each
of the charged particles is substantially increased within their
respective sections of the accelerator chamber to the order of a
fraction of the speed of light, while temperatures of the order of
200.degree. to 5,000.degree.F. may be attained in the production of
electrons and positively charged deuterium ions. After emergence
from the respective accelerators, the streams of positively ionized
deuterium and negatively charged electrons are synchronously and
constantly altered by the positive and negative beam scanners 26,
27, to change the directional characteristics of the resulting
neutralized particle beam. The beam is thus continuously scanned
through a rectangular pyramid having its apex about the
neutralizing point P in the accelerator chamber and its base
centrally located in a projected rectangular target area T on the
inner plane wall of casing 31 opposite window 10 through which the
neutralized particles pass to enter raction chamber 30. Window 10
in the example given is preferably constituted of the element iron
which is essentially transparent to the passage of the neutralized
deuterium beam. The desired velocity of the neutral particle beam
is attained by the variable potential controls provided as an
inherent part of each positive ion generator 12 and negative
particle generator 14 which need not be shown, being known in the
art.
As noted, the reaction chamber, having been evacuated to a pressure
of the order of millimicrons, is desirably charged with a gaseous
neutral reactant, such for example as molecular hydrogen in the
form of molecular deuterium (D.sub.2) from the storage resevoir 39,
the amount admitted being controlled manually in response to
conditions in the reaction chamber as reflected in readings of the
pressure gauge. Hence, as the accelerated and neutralized deuterium
particles enter the reaction chamber 30 through the iron window 10
they encounter and collide at high velocity with the relatively
static particles of molecular deuterium in the chamber 30, the
resultant reaction producing the products normal hydrogen ions and
tritium ions and substantial energies of radiation at the point of
impact. These energies are thereupon dissipated as heat to the
walls of the reaction chamber which for this purpose should be as
heat conductive as may be consistent with other structural and
chemical necessities so as effectively to transmit the sensible
heat absorbed from the radiant energy of the reaction to the fluid
medium being circulated through the heat exchange jacket 40. This
heat, of course at a considerably lower temperature than
momentarily attained at the points of impact of the particles, can
then readily be availed of for ordinary heating purposes,
electrical energy generation or for directly operating a heat
engine if preferred, its utilization after it has been transferred
to the fluid medium circulating through the heat exchange jacket 40
constituting no part of the invention. The dimensions of reaction
chamber 30 are, of course, sufficient to effectively handle the
heats of radiation from reaction without jeopardizing the material
integrity of the inner reaction chamber walls.
The admission of particles of reactant, molecular hydrogen in this
instance, to the reaction chamber 30 is desirably so controlled
that the quantity of particles in the chamber at any instant is
approximately such that the mean free path of travel of an
accelerated neutral particle therein without encountering a
particle of the relative static reactant, is not appreciably
greater than one half of the distance from the entering window 10
to the opposing target T. At that rate of admission of reactant
substantially 100 percent reaction of accelerated particles with
the relatively static reactant particles is assured, with maximum
conversion of particle energy to sensible heat for useful purposes.
The gaseous reaction products are withdrawn from the reaction
chamber by the vacuum pumps 33, 34 which as will be well
understood, are desirably maintained in constant readiness, if not
continuously operating, so as to maintain the desired low pressure
conditions when the apparatus is operating effectively. To assist
in preserving the integrity of the walls of the accelerator chamber
and of the reaction chamber by limiting diffusion of particles
therethrough they may be coated with tin, cadmium, zinc or other
appropriate material if desired, whereby wasteful dissipation of
energy otherwise than as sensible heat may be kept at a
minimum.
In order to avoid excessive ionization in the neutral particle beam
it may be found advisable in some instances to position an electron
gun disposed to discharge electrons into the reaction chamber in
the general direction of the neutral particle beam to flood the
reaction chamber with a surplus of electrons, thereby neutralizing
any positive ions in the chamber and maintaining the integrity of
the neutral particle beam.
In some instances it may be preferred to employ solid or liquid
reactants in reaction chamber 30 for producing the particle
reaction and consequent generation of heat. An example of a
reaction with a solid is the utilization in place of the evacuated
reaction chamber 30 of a solid cast body of an alloy of
uranium.sup.235 or plutonium.sup.239 or both in iron, with the
radioactive element disseminated uniformly throughout the iron
matrix and confined within a heat exchanging jacket comparable to
the jacket 40 surrounding the reaction chamber 30 in FIG. 2. Vacuum
conditions are not required by the solid mass in this instance and
the particle generator and accelerator unit 1 or a plurality of
such units should be arranged to direct a beam or beams of
accelerated neutral particles directly into the solid reactant
bearing mass, eliminating the need for a window such as window 10
in FIG. 1. An accelerated beam of protons neutralized by electrons
within the neutral particle accelerator chamber may be utilized to
provide the neutralized accelerated beam of normal hydrogen atoms
directed into the inert iron matrix containing the uranium.sup.235
or plutonium.sup.239 in quantities below critical mass. Such an
accelerated beam of neutral hydrogen atoms should continuously be
directionally altered within the mass as a result of the operation
of the synchronous scanning devices upon the respective electron
and proton streams before being united into a continuously scanning
accelerated neutral hydrogen beam. Again, the heat produced from
the interaction of the accelerated neutralized hydrogen beam with
the reactant uranium.sup.235 or plutonium.sup.239 within the solid
alloyed mass should be continuously removed from the core of the
reactor as a result of the flow of the heat transfer medium about
the core. The iron matrix in this case would be transparent to the
flow of the accelerated neutralized beam of normal hydrogen
atoms.
In another typical reaction, which might be carried out in the
neutral particle accelerator and reaction chamber, accelerated
neutralized deuterium particles would enter reaction chamber 30
through the iron window 10 to react with gaseous nitrogen 14 within
the reaction chamber to produce the products carbon 12 plus normal
helium plus the energies of reaction.
If preferred, apparatus other than that thus far specifically
described may be devised for practicing our invention and we have
illustrated diagrammatically in FIGS. 3-5 some of the forms such
apparatus may take. Thus, in FIG. 3, a reaction chamber 50
constructed substantially in accordance with the principles
heretofore described may be provided with windows or access
connections (not shown) at each of its plane circular ends, with
particle generator, accelerator and neutralizer units 51, 52,
including scanners, disposed respectively for projecting
directionally variable scanning high velocity beams of neutralized
particles into the reaction chamber along converging paths for
interaction within the reaction chamber in the vicinity of a
predetermined point of convergence of the beams, or a larger number
of units may be employed if desired.
For example, in FIG. 4 a cylindrical reaction chamber 55 may have
radially disposed neutral particle accelerator units 56, 57, 58 and
59 or if chamber 55 as illustrated be deemed to represent a
spherical chamber an even larger number of units (not shown) may be
disposed radially with respect to it at appropriate intervals to
insure projection into the reaction chamber of a desired number of
high velocity beams of accelerated neutral particles.
In another arrangement illustrated in FIG. 5 a reaction chamber 60
which may be cylindrical, polygonal or any other appropriate shape,
may have opposed rows R, R1 or a plurality of particle generator,
accelerator and neutralizer units, with scanners, communicating
with its interior through generally similar spaced windows (not
shown).
The accessory equipment (not shown) for all these accelerator
chambers substanially corresponds to the vacuum pumps, heat
exchange fluid supply and discharge means and reactant supply and
control apparatus heretofore described in association with the
accelerator chamber in the preferred embodiment of the invention,
while the several accelerated neutral particle projection units
themselves may substantially duplicate in their entireties the unit
1 likewise heretofore described.
As an example of the utilization of our accelerated neutral
particle projection apparatus for purposes other than heat
generation we have diagrammatically illustrated in FIG. 6 an
arrangement of a unit 65, producing a beam constantly scanning
highly accelerated neutral particles projecting from its restricted
end toward a sensitized detector D, backed by a shield S, whereon
particles projecting the profile of an article A to be
radiographically examined provide an image of a fault O or other
interruption in the physical or chemical homogeneity of the article
A as measured by its transparency to high velocity neutral
particles.
* * * * *