An X-Y plotter circuit apparatus is described which displays an input pulse representing particle parameter information, that would ordinarily appear on the screen of an oscilloscope as a rectangular pulse, as a single dot positioned on the screen where the upper right hand corner of the input pulse would have appeared. If another event occurs, and it is desired to display this event, the apparatus is provided to replace the dot with a short horizontal line

Hansen, D. O.

Roy, N. L.

English

NASA Technical Reports Server

National Aeronautics and
Space Administration
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FROM: GP-4/Office of Assistant General
Counsel for Patent Matters
SUBJECT: Announcement of NASA-Owned U.S. Patents in STAR
In accordance with the procedures agreed upon by Code GP-4
and Code NHB, the enclosed NASA-owned U.S. Patent is being
forwarded for abstracting and announcment in NASA STAR.
The following information is provided:
U.S. Patent No.
Government or
Corporate Employee
Supplementary Corporate
Source (if applicable)
NASA Patent Case No.
3,423,627
TRW, Inc.
Redondo Beach, CA
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NOTE - Is this an invention made by a corporate employee.
of a NASA contractor? YES (
 x | NO
If "YES" is checked, the following is applicable: Pursuant
to Section 305(a) of the National Aeronautics and Space Act,
the narno of the Administrator of NASA appears on the first
page oL" the pa ton I".; however, t'lK; name of the actual .in v -n tor
(author) appeal".'-", at the lwid:i. tiq of column Mo. .1 of the
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Elizabeth A. Carter,^
Enclosure
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Jen. 21, 1969
Filed Jan. 28. 1966
D. O. HANSEN ET AL 3,423,627
PAJTrlCLE PARAMETER ANALYZING SYSTEM ' "'
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nd 0. Hansen,
Neal L. Roy,
INVENTORS.
BY.
AGENT.
Jan. 21, 1969
 D. o. HANSEN ETAL 3,423,627
PARTICLE PARAMETER ANALYZING SYSTEM
Filed Jan. 23. 1966. , Sheet 2 of 2
Fig. 3d.
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Fig. 3b:
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Fig.4.
Oscilloscope
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David 0. Hansen,
Neal L. Roy,
.INVENTORS.
BY.
AGENT.
United States Patent Office 3,423,627Patented Jan. 21, 1939
3,423,627
"PARTICLE PARAMETER ANALYZING SYSTEM ,
David O. Hansen, Westminster, and Ncal L. Roy, Re-
dondo Beach, Calif., assignors lo TRW Imu, Redondo
Beacb, Calif., a corporation of Ohio
Filed Jan. 28, 1966, Ser. No. 523,632
U.S. CI. 315—22 8 Claims
Int. Cl. HOlj 29/70
ABSTRACT OF THE DISCLOSURE.
X-Y' plotter circuit apparatus which displays an in-
put pulse representing particle parameter information,
that woulu "ordinarily appear on the screen of an oscillo-
scope as a rectangular pulse, as a single dot positioned on
the screen where the upper, right-hand corner of the in-
put pulse woiild have appeared. If another event occurs
such a's.impact of the particle with a" target, and it is
desired to display this event, apparatus is provided to
replace the dot with a short horizontal line segment;
This invention relates generally to two dimensional
particle analyzer circuits, and more particularly relates to
an, X-Y plotter circuit capable of use with an oscillo-
scope.
The invention described herein was made in the
performance of work under a NASA contract and is sub-
ject to the provisions of Section 305 of the National
Aeronautics and Space Act of 1958. Publi: Law 85-568
(72Stat.435;42U.S.C.2457). . ' "
Improvements in apparatus and techniques used with
presently known electrostatic hypervelocity accelera-
tors have enhanced their performance and increased their
versatility. Particle detector preamplifiers also have been
improved to the point that much higher velocity panicles
may be detected. In addition, high repetition rale particle
injection systems are available for use in experiments re-
quiring a large particle flux.
One disadvantage that has arisen from improved ac-
celerator'performance is that the increasing rate of data
acquisition has necessitated more complex computa-
tional procedures than those originally used. In general,
particle parameters were heretofore 'determined from
arithmetical computations involving the amplitude and
duration of the detector signal and other system varia-
• bles. Although the calculations are straightforward, they
are time consuming, and are not practical for large
volumes of data. The particle parameter analyzing sys-
• tern of the present invention eliminates the above disad-
vantages.
The particle parameter analysis system' of the present
invention comprises essentially an electronic X-Y plotter.
In this system each particle is represented by a point on
a two-dimensional oscilloscope display. The displace-
ment of the point along the Y axis is proportional to the
charge on the particle, and the displacement in the X
direction is proportional to its transit time through a par-
ticle detector. Since each particle is represented by a
single point, r..ther than by a rectangular pulse as in
previous oscilloscope displays, a large number of data
points can be placed on a single display before confusion
arises. Thus, briefly, in accordance with one embodiment
of the present invention there is provided X-Y plotter
circuit apparatus whereby an input pulse representing par-
ticle parameter information by means of its height and
duration, that would ordinarily appear on the screen of
an oscilloscope as a rectangular pulse, is replaced by a
single dot which appears at the place on the screen where
the upper right-hand corner of the rectangular input pulse
would have appeared. Moreover, if another event occurs,
such as impact of the particle, with a target, within a pre-
determined time period, and it is desired to record or
display this event, the dot can be replaced by a short
horizontal line segment in other embodiments of the in-
vention. - . "'
-. Accordingly, one object of the present invention is the
provision of particle analyzing apparatus capable of rep-
resenting certain parameters of a particle, such as charge
and transit time through a detector, as a single point on
10 an oscilloscope display screen.
Another object of the present invention is the provision
of particle parameter analyzing apparatus capable of dis-
* • playing a large number of data points on a single dis-
play. . <
15 One other object is the provision of particle analyz-
ing apparatus: which is not only capable of displaying a
representation of certain parameters of a particle, such as
charge and transit time through a detector, but is also
capable of displaying -the occurrence of another event,
20 , such as collision of the particle with a.target.
These and other objects will be more clearly apparent
when taken in consideration with the following detailed
description and drawings'wiierein:
FIG. 1 is a block diagram showing of one embodi-
25 ment of the invention; •
FIG. 2 is a block diagram showing of another em-
bodiment of the invention;
FIGS. 3(a) and 3(6) are displays to be found on the
cathode ray tube of an oscilloscope in accordance .with
30 the present invention; ard
FIG. 4 is a block diagram shotting of still another em-
bodiment of the invention.
Referring to FIG. 1 wherein one embodiment of the
X—Y plotter circuit of the present invention is shown, an
35 information input pulse from a particle detector (not
shown) is fed through a detector preamplifier 10 to a
pulse stretcher 12, a discriminator 14, and a differentiat-
ing circuit 1*. The pulse stretcher 12 generates a''
stretched pulse which has the same amplitude as the rec-
40 langalar information pulse fronTthe preamplifier 10 but
is much longer in time duration. The stretched pulse is
then applied to the . vertical plate input circuit of an
oscilloscope 18, wherein the oscilloscope electron beam
is deflected vertically by an amount equal to the height
or amplitude of the information pulse from the pream-
plifier 10.
At the same'time that the stretched pulse is applied
to, the. vertical plate circuit of the oscilloscope 18, the
discriminator 14 produces a trigger pulse to the hori-
zontal plate sweep circuit of the oscilloscope when the
information pulse exceeds a predetermined threshold.
The information pulse is also fed to the differentiating
circuit 16 which produces -a positive pulse that is gen-
erated at a time coincident with the leading edge of the
information pulse, and a negative pulse which occurs at
a time coincident with the trailing edge of the informa-
tion pulse. The negative pulse from the differentiating
circuit 16 is applied to a brightener pulse generator 20
which produces in its output a short duration, rec-
tangular voltage pulse to the cathode of the oscilloscope
18. The brightener pulse generator 20 can be a conven-
tional one-shot multivibrator or the like. In actual opera-
tion the beam intensity control (not shown) of the
oscilloscope 18 is adjusted so that a trace is visible on
the cathode ray screen of the oscilloscope only when the
brightening pulse from the brightener pulse generator 20
is applied to the oscilloscope cathode. It will be appre-
ciated that since brightening of the oscilloscope screen
70 occurs at a time coincident with the trailing edge of the
information pulse and, at the same time, the vertical dis-
placement of the oscilloscope electron beam is proper-
._
so
5-
GO
3,423,627
tional to the height of the information pulse, the posi-
tion of a brightened spot provides the desired particle
parameter information.
A further feature: makes provision for the display of
the horizontal sweep circuit of the oscilloscope 42 and
the output pulse from the time base SO is applied to a
briij&tener puke generator circuit 54 and a coincidence
gate 57- which could be similar to the brightener pulse
experimental information regarding the effect of particle - generator, circuit 34 and coincidence gate 36, respectively,
impact after" the particle has passed through the particle
detector (not shown). Generally this feature is restricted
to a simple ''yes-no" type of response. A second embodi-
ment o£ this invention for implementing this response is
shown in FIG. 2. The stretched pulse from a-pulse JQ
stretcher 22 is applied to the vertical input of an oscillo-
scopi 24 after an information pulse passes through a
detector preamplifier 26, as in the first embodiment, but
output pulses from a differentiating network 28 are ap-
plied to two one hundred microsecond duration delay 15
multivibrators 30 and 32. The first of these multivibrators
30 is triggered by the positive pulse from the differen-
tiating network 28 corresponding to the leading edge of
the information pulse from the preamplifier 26, while the
of the previous embodiment of FIG. 2. Similarly the
brightener pulse generator 54 produces a brightener pulse
of short duration which pulses the cathode of the oscillo-
scope 42, as in the previous embodiment. If a second in-
formation pulse is received from an experiment source
56 before the pulse from time base generator 50 is com-
pleted and applied to the coincidence gate 57, which is
opened, the brightener pulse from pulse generator 54 is
lengthened a predetermined time: As before, points are
plotted on the screen of oscilloscope 42 for "no" events
as in FIG. 3(a), and short lines for "yes" events as in
FIG. 3(6). ' , . •
It will be appreciate'd that the apparatus of the embodi-
ment of FIG. 4 can be modified to eliminate the capability
second multivibrator 32 is triggered by the negative pulse 20 of, displaying dots or lines simply by removing the two
which occurs at the trailing edge of the^ information time bases 48 .and 50. from the circuit. In that event, of
signal. The trailing edge of the output pulse from the first course, the displays will be conventional squarewave dis-
multivibrator 30 is used to trigger the horizontal sweep,
circuit, of the oscilloscope 24. The pulse from the second
plays of particle collisions and parameters.
It will also be appreciated that display of data by the
multivibrator is fed to a brightener pulse generator 34 25 apparatus of < the present invention can be recorded
and a coincidence gate 36. The brightener pulse generator
34 can be a one-shot multivibrator with two time con-
stants; the time constant that is actually used is determined
by the coincidence gate 36, which is triggered by a signal
photographically and the amount of • data- that can be
distinguished in each photograph is increased by several
order; of magnitude. The device of the present invention
produces results equivalent to results produced by previ-
from an experiment 37. If no input is provided to the 30 ous. multichannel pulse height analyzers, and provides the
gate 36, the trace on the screen of oscilloscope 24 be- •- added advantage tha't "yes" or "no" indications can be
comes brightened in exactly the same manner, as described shown on a two-dimensional photographic display,
in the first embodiment by the production of a short Changes can be. made in the combination and steps
duration brighiener pulse from the brightener pu!se""geaer- and procedures, as well as parts or elements, as heretofore
ator 34, as determined by one of the heretofore menr 35 set forth in the specification and shown in the drawings
tioned time constants of the multivibrator, except that without departing from the spirit and scope of the ihveri-
tbew is-a one hundred microsecond delay in the genera-
•tion of the pulse.
The "yes-no" feature is characterized by changing fie
duration of the brightener pulse from circuit 34. This is 40
accomplished when a second information pulse from the
experiment 37, which represents impact of tie particle
on a target, is applied to the coincidence gate J6. If the
second pulse appears before the completion of the pulse
from- multivibrator 32, the gate 36 is opened and the
 45
brightener pulse from the pulse generator 34 is rendered
several times longer, depending on the second time con-
. slant, than if the second pulse had not appeared. This
.results in points being plotted on the screen of oscillo-
scope 24 for "no" events as in flG. 3 (a) for -no impacts 59
and short lines being recorded for "yes" events as in FIG.
3(6) when impacts occur. The analysis of particle param-
eteis would be the same in any case. As can be seen,
this feature is most useful in experiments which are con-
ducted on the initiation of voltage breakdown by particle 55
impacts with targete.
Referring to FIG. 4 wherein there is shown still another
embodiment of the invention, the rectangular information
pulse from a particle detector (not shown), is applied
to a pre-amplifier 38, a pulse stretcher 40, and then to g^
the vertical input circuit of an oscilloscope 42, as in the
previous embodiments. Simultaneously the input signal
is applied to a first and second similar discriminators 44
and 46. The first discriminator 44 fires at a predetermined
set level on the leading edge of the input pulse to produce gg
a trigger pulse to a first time base generator 48. The
second discriminator 46 fires on the trailing edge of the
input pulse and generates a trigger pulse to a second time
base generator 50.
Both the time base generators 48 and 50 can be delay
 70
. multivibrators which produce delayed pulses similar to
the pulses produced by the multivibrators 30 and 32, and
delayed, for example, a similar period of one hundred
microseconds.
lion as defined in the following claims.
The embodiments of the invention m which an exclu-
sive property or privilege is claimed are defined as fellows:
1. Apparatus of the type described comprising:
means responsive to an information input pulse for gffl-
erating an output pulse to be applied to the vertical
plate circuit of an oscilloscope, said output pulse hav-
ing an amplitude equal to and a time duration greater
than that of said information input pulse, ',
means responsive to said information input pulse for
generating first and second "pulses having leading
edges time coincident with the leading and trailing
edges of said input pulse, respectively, said first-pulse
being adapted for application to the horizontal plate
•sweep circuit of the oscilloscope, and
means responsive to said second pulse for generating
a brigbtener pulse to be applied to the-cathode circuit
of the oscilloscope.
2. Apparatus as set forth hi claim 1, said first and sec-
ond pulse generating means comprising:
discriminator means for generating said first pulse whem
said input pulse exceeds a predetermined amplitude,
and
differentiator circuit means for differentiating said input
pulse to generate a pair of positive and negative
pulses, said negative pulse being said second pulse
and time coincident with the trailing edge of said in-
put pulse.
3. Apparatus as set forth in claim ], said first and sec-
ond pulse generating means comprising:
differentiator circuit means for differentiating said in-
put puise to generate a pair of positive and negative
pulses, and
first and second pulse generators responsive to said
positive and negative pulses, respectively, for generat-
ing delayed first and second pulses.
4. Apparatus as set forth in claim 3, said first and sec-
The output pulse from the time base 48 is applied to 75 ond pulse fenerators comprising one-shot multivibrators,
3,423,627
respectively, for generating said delayed first and second
pulses.
5. Apparatus as set forth in claim 3, wherein said
brightener pulse generator means comprises:
a one-shot multivibrator having first and- second time
constants, said one-shot multivibrator being normally
responsive to said second pulse to generate said
brightener pulse having a short time duration as
determined by said first time constant, and
a gate adapted- to be opened by a second information
pulse occurring before completion of said second
pulse to generate said brightener pulse having a
longer time duration as determined by said second
ti'.ie constant
6. Apparatus as set forth in claim 1, said first and sec-
ond pulse generating means comprising:
first discriminator means responsive to the leading edge
of said input pulse for generating a first trigger pulse
when said input pulse exceeds a predetermined
amplitude,
second discriminator means responsive to the trailing,
edge of said input pulse for generating a first trigger
pulse when said input pulse exceeds a predetermined
amplitude, and ; [
first and second pulse generators responsive to said first
and second trigger pulses, respectively, for generating
delayed first and second pulses.
15
20
25
7. Apparatus as set forth in claim 6, said first and sec-
ond pulse generators comprising time base generators . >r
generating said deiayeii first and second pulses.
8. Apparatus as set forth in claim 6, wherein said
brightener pulse generator means comprises:
a one-shot multivibrator having first and second time
constants, said one-shot multivibrator being normally
responsive to said second pulse to generate said
brightener pulse having a short time duration as
determined by said first time constant, and
a gate adapted to be opened by a second information
pulse occurring before completion of* said second
pulse to generate said brightener pulse having a
* ' longer time duration as determined by said1 second
time constant.
 :
References Cited .
UNITED STATES PATENTS
2,830,227 4/1958 Hasbrook __„ 315—22
RODNEY D. BENNETT, Primary Examiner.
T. H. TUBBESING, Assistant Examiner. ^ . ' '"
U.S.CLX.R.
315—25; 324—121 ' :


Particle parameter analyzing system

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