NATIONAL BUREAU OF STANOARDS REPORT

2281

CathodS’Ray- Oscillograph Beam intensification

John H. Park and H. N. Cones

Electricity Division

Electrical Instrument Section

Sponsored by

Office of Basic Instrumentation

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

By
U. S. DEPARTMENT OF COMMERCE

Sinclair Weeks, Secretmry

NATIONAL BUREAU OF STANDARDS

A. V. xistin. Director THE NATIONAL BUREAU OF STANDARDS

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NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT MBS REPORT

0103-23-2006 February 1953 2281

Catbode-Ray- Oscillograph Beam Intensification

By

John H. Park and H. N. Cones

Electricity Division

Electrical Instrument Section

National Bureau of Standards

Sponsored by

Office of Basic Instrumentation

The publication, reprin < i r i i i itt, If prohibitod Approved for public release by the , unless permifflon If obi . • irdf,WMhlng1on 25.D.C. Suchpermi. Dircctor of the National Institute of ^a. been .pecifleaiiy prepared If that Standards and Technology (NIST) t for iti own uie, on October 9, 2015.

FOREWORD

This work was conducted as part of the National Bureau of Standards Basic Instrumentation Program, jointly sponsored by the Office

of Naval Research^, the Air Research and Development Command, and the

Atomic Energy Commission^ Progress on all projects underway as part

of the program is reported in Office of Basic Instrumentation Progress Reports

o

This final report on this project describes the work done in an

effort to obtain a better understanding of electron beam intensification phenomena, to obtain improved results, and to obtain optimum

design of equipments A description of the phenomena, and a method

for applying it to a cathode-ray oscillograph have been reported in a previous paper® 1/

Fo Bs Silsbee, Chief

Electricity Division

Ao Vo Astin

Director
-2»

When the ^’starting switch’® is closed the 0ol5 capacitor dischargesj

putting a steeply rising pulse on both the cable going to the surge

generator tripping circuit and the delay lines which control the time

of firing of the I4C 35 hydrogen thyratrona Two adjustable delay lines

as shown in figure 1 are used^ one consisting of 10 sections of 1 microsecond delay each and the other consisting of 10 sections of Ool microsecond delay each. Control crf-tming in iii© range 0 to Ool microsecond

is obtained by varying the adji^abl© resi^stor (O to 10|,000 ohms) in

series with the 100 capacitor used to connect the output of the

delay lines to the grid of the l:ydrogen thyratrone IrJhen this tube fires

the lo 5 and 0 o 05 p£ capacitors discharge^ producing pulses which ( 1) unblock the oscillograph beam by use of tte Kbrinder Relay plates^ (2)

cause beam intensification (the method of applying ttie intensifying

pulse to the CRO discharge tube eireult is in RoP® Noo 2231 )j, and ( 3 ) apply a sweep voltage to the CRO meep plates after a 0o2$

microsecond delay® ^ adjusting the delay lines ar^r given part of the

surge being measured can be displayed on the GRO sweep® In case tier©

is very little or no delay in the surge generator trip circuity it may

be necessary to send the surge g^rterator trip pulse through an additional delay line® The use of delay lines in the tripping circuits

allows timing to be adjusted to within 0»01 microsecond or less®

The beam intensification permits hi^er sweep speeds to be easily

and regularly used^ thus a means must be provided for easily calibrating such sweeps® A seven ir^^cycle crystal controlled oscillator with

one stage of amplification vras constructed which gives an output of

several hundred volts across the deflection plates of the CRO® A frequency tripling circuit ,and anotlier tuned amplifier were made so that

a sweep calibrating frequency of 21 me^cycles is available® This

sweep calibrating equipment was built into one shielded box and permanently mounted on the CRO panel so that it would always be available

for use with the CRO®

Another permanent addition to the CRO wa^ the installation of

two thermocouple vacuxmi gages^ one in the exhaust port of the discharge

tube, the other in toe etoaust port, of the main CRO deflection chanibero

Heater supply meters and micTO^mneters for indicating the output of the

couples were mounted in a panel on the CRO® The thermocouple in the

discharge tube port was used to furnish a record of the pressure in

the discharge tube under various conditions© Both gages are valuable

additions to the CRO since they give an exact indication of pressure

in the CRO chambers and show ^<hen the pressures are correct for operation of the CROo They have already proven very useful in detecting

small leaks and indicating other non-operable conditions such as too

much moisture in the filuio
’3“

Ille Esperiinents on Beam Intensification

In an effort to obtain a better understanding of the intensi=

fication phenomena several independent experiments were perfomede

These will now be described in approximately the order in which they

were done®

lo Results with a Metal Discharge Tube

For th© esqperiments described in Research Paper 2231 a CRO with

a glass discharge tube was psed as indicate in figure 1 of that

paper® This glass tube has an outside dimtieter of 1 inch and is about

16 inches long® The end of the cathode is about li inches above the

upper end of the met^ anode tube which is inside the glass tube®

Other e3q>erimentere^ bav© used an all 'mstal disch^ge tube in place

of tlie gla,ss tube© The catted© in that case is insulated from the

metal tube by a glass or porcelain bushing^ but extends below this

insiuation down into the metal tube© In order to determine whether

or not the surface charges on the glass tube had effect on the

intensification ihenomena it was decided t@ try the intensificatioa

technic|2.e with a metal rather than insulating tub© surrounding the

cathode©

Attempts were first made by using a longer anode tube inside the

glass tube and putting an ext^i^ion on the cathode so “Siat the end of

the cathode extended about 1 inch into the anode tube© Ifowever^, since

the anode tube ia smaller (about 3/li ii«h C®) than the glass tube^

flastever between cathode and anode tibe occurred before a steady beam

could be established® In order to increase -tiie spacing between the

cathode and the grounded anod© tube a combinatioii metal and glass

(’®glassc=metal'”') discharge tube was constructai as shown in figure 2©

By carefully centering the cathode on fee axis of fee metal tubs a

discharge and electron beam along tte tube axis could be obtained©

The beam, intensity could be regulated in the usual way by a fine con=

trol on the pressure in. the discharge tube©

With the combination ®”glass=>metal®® tube the metal tube was insulated from the anod© electrode' (with th© small hole for lett.lng the

electron beam into the main CRO chamber) by rubber gaskets | thsis the

total, current throu^ the discharge couM be measured as two pa.rts - that coming from cathode to metal tube and that coming from cathode

^

Je Mo Dodds - ^^Metallentladungsrohr'*'^ Arch© f© Elektro© 29 p© 69

1935®

Burch and Whelptcn - '^The Technique of fe© Speed CRO*®

(London) 71 p® 380 1932®
to anodao This was done for ^rious values of discharge current and

for the cathode at various distances from the anodeo In all cases where the cathode extended down into the metal tube^, about 60 percent

of the total current to the cathode ms collected at the anode^ the

remaining 1|0 pm^ent being collected by the metal tubeo With the end

of the cathode about 3 inches above the end of the metal tube so that

part of the discharge was enclosed by i^e ^ass tube^ about 5^ percent

of the total current went to the anode and to the metal tube® In

aH cases very little of the total c-attete- current (1 percent or less)

passed through the anall tele in the anode to be utilized as the elec=

tron be^ for measuring purposes©

Intensifying pulses the same as those described in Research Paper

2231 and shown in figures 2 ate 3 of that paper (these figures are

reproduced in this report as figures 3 and I4.) were applied in tests

using the combination ** glass metal** tube© With the cathode above the

metal tube so that part of the discharge was in the glass tube^, the

discharge currents and bessti intensification were almost exactly the

same as with an all glass discharge tube (see figures 3 and I;)© With

the cathode extending into the metal tube (same as an all metal dis=

charge tube) the results were quite different as indicated in figures

5 and 60 Beam intensification and second increase in discharge cur^

rent did not occur^ as seen by comparing figures 3A and Also^

there was no reversal of discharge current as may be seen by coiqjaring

figures I4B and 6b<s

2© Trial of Various Gases in Discharge Tube

Several gases^ some with molecular wei^ts qiite different from

the nitrogen and oxygen in air^, which is normally used^ were tried in

the loW“pressure discharge tube to determine whether there was a dep«

endence of intensification on the molecular ^constitution of the gas

usedo This was accomplished by using 'Sie CRO film drying chamber

(a heavy wall tube 5 inches in diameter and 10 inches long) as a stor=

age tank for 'the gas to be used© This chamber was used because it was

available on the CRO and could be “evacuated by the CRO fore pump©

Vacuum tight connections were made (1) from^the film chamber to the

intake of the CRO leak valve -tdiich regulated the flow of gas into the

discharge tube and (2) from the film chamber (through a valve) to a

regulating valve on a cylinder of the gas being used© A pressure gage

was connected to the film chsmber© Hie procedure was than (1) to

evacuate the film chamber by opening a vklve from it to the CBO fore

pumpj (2) to close this valve^ (3) to allow gas to flow from the gas

cylinder into the film chairber by opening the regulating valve first

and then the valve on the line into the film chamber^ allowing enough

gas to flow into the film chamber to bring its pressure slightly above

atmospheric^ and (li) to close the valve on the intake line to the film

chamber© When a gas cylinder was first csonnected to the system this
ptrocedure was repeated in order to flush out any gas left in the system

from previous tests « The leak 'valve on the CRO discharge tube inlet

was then adjusted in the usual manner to regulate pressure in ilie dis=

charge tubeo The volome of gas in the film chamber was sufficient for

several hours operation of Ihe CRO but when the pressure in the film

chamber fell to atmospheric,, more gas was let in from the cylinders A

tray of phosphorous pentoxide was kept in the film chamber to remove

moisture from the gas being used®

For these esq^eriments with various gases an all glass discharge

tube and the regular cathode and anode tube were usedo "When i^drogen

was used the pressure in ihe discharge tube had to be much higher than

with air and since both the discharge tube and the deflection chamber

of the CiSD are evacuated by the same molecular pump^, pressure in the

deflection chamber was also highere This at first resulted in flashover

between sweep plates #ien sweep voltage was applied but by using a special sweep at reduced voltage^ records with I^drogen were obtained

under iiie same circuit conditions as used for figures 2 and 3 of RP 2231,

Ihe intensified discharge occurred for hydrogen essentially the same as it had for airo lifoen helium was used the discharge pressure had to be

much higher than for air but mt as high as for hydrogeni no flashover

between sweep plates was noteda Intensification occurred in the same

manner but to a somewhat less degree than for air® When o.xygen was

used the pressure in the discharge tube was slightly lower than for air

and the beam was very unsteadji ho'wever^ records were obtained and the

intensification was essentially the saire as for air^ When nitrogen

was used the pressure in tiie discharge tube was also slightly lower than

for air but the beam behaved normally and the intensification was the

same as for air® Carbon tetrachloride (C ) gas was also tried ty

using a flask of liquid C Gl|, in place of the cylinder of and allowing C Clt t@ bon off into the film chamber after it had been evacuated®

With C CI|^ the beam behaved very well and the pressure in the discharge

tube was about the sail® as for air| the intensification obtained was very nearly tha same as for air®

The esqjariments with various gases showed slight differences iji

degree of intensification but ttie general nature of the intensification

appiears to be the. same for all gases tried® Dry and moist air were also

tried without observing significant differences

3o Changes in Geometry of Cathode

The cathode of the discharge tube as normally used^ consists of a l/ii inch diameter aluminum rod^ xfith the surface on its emitting-end

polished^ placed axially inside a steel shield as shown in figure 7o

The small, aluminum cylinder is held in place with a set screw and can

be removed for re=polishingo The polished surface of the cathode is

normally set at a distance d " im (see figure 7) -inside the cathode
shield* With this cathode setting the appearance of the discharge in

the glass tube is about as showi in figure The electron beam may

be seen as a fine blue line starting at the center of the emitting=end

of the cathode and foUo^ng along the axis of the ^ass tube down into

the metal anode tube© A blue fluorescent band spears on the inner

surface of the glass tube at a distanc© '^"below ihe cathodeo Its upper

edge is bright and sharply defined* When this edge appears tilted

rather than perpendicular to the axis of the tube it is indicative of

malcentering or iralaligment of parts* ( Inspection of this sharp edge

of fluorescence offers a good guide for lining up the axis of the

cathode)© The distanced from the lower edge of 1he cathode shield

to this fluorescent line is always about 2 cm with the usual cathode

setback in its shield®

It was found that a change in the cathode setback d caused a change

in the distance ^ thus indicating a change in charge distribution

inside the ^ass tube near the cathode* The effect of changing d on

the intensification phenomena was ttierefore irnresti^ted® When d was

made eqml to zero (cathode and shield lii&ed up) the distance-^ was

found to be reduced to about 1*1 cm and when d was changed to “1®55 inm

(cathode below shield) became 0»8 cm® Under both conditions beam

intensification still .occurred in the sauB manner as with normal cathode

setback but the degree of intensification was much less® When the

cathode setback d was increased to 3 iroi the distanced was found to in° crease to 3»5 cm® Bean intensification still occurred in the same

manner but somewhat increased in magnitude over that obtained with nor“

mal cathode setback®

ho Metal Bands Around the Discharge Tub©

As indicated in the previous section a change in longitudinal

position of the discharge sheath along the inside surface of the

glass tube was accompanied by a change in magnitude of the intensification® This suggested that another kind of experiment be performed*

That metal foil bands be wrapped around the outside of the ^ass tube

and be either connected to ground or excited by a pulse with respect

to grounds Trials were made with l/2‘* and 1’* wide bands placed

tightly around the glass tube at various positions along its axis between the cathode and anode® Placii^ the band less than 3 cm from the

cathode caused the bean to become unsteadyo The effect of these bands

on the intensification is quite spectacular and varied® Under most

conditions they increase both the magnitude and duration of intensification but when the beam intensification is p^eatest it appears to come

in "spurts** and does not yield a unifom trace*

Placing the metal bands around the glass discharge tube undoubtedly causes changes in potential distribution and thus charge density

inside the tube® The observed effects on intensification were quite
7-

large but results were not always repeatable a Refinements in the

techniques for applying bands to the glass tube will need to be made

before proper control can be obtained for CRO applicationSo

5o Full Voltage Suddenly Applied to Discharge Tube

The intensification reported above was caused, by a suddenly

applied change in the total voltage across tbe disch^ge tubes of only

about 2 to 5 percent of the vDltage* In normal operation of the CBO

the discharge tabe voltage is gradually increased to its normal operating value and a steady state equilibrium condition in the discharge

is always maintainedo A small sudden change in voltage as has been

explained gives momentary beam intensificationo The question arose as

to what would happen if the full voltage were suddenly applied to the

glass discharge tube®

Several designs of quick acting mechanical switches^, operating

both in air and under oil were tried for suddenly applying the voltage®

In aU cases it was found that connection was made by a spark in the

insulating medium of the switch prior to metallic contact of the switch®

The characteristics of this spark determine how quickly the voltage is

applied and whether the initial connection i^ stable® Therefore a three-ball sphere gap was used to suddenly apply the voltage^ the time

of application being controlled by a steep voltage pulse to the middle

ball® It was found that the impedance of the spark between the spheres

does not reach a low and definite value unless the current in the spark

exceeded 10 ma® The circuit for suddenly applying voltage oonsisted of

a high voltage capacitor (charged to 5P K\T) that was discharged through

a high resistance by the three ball ^p® The CRO discharge tube was

connected across this resistor so that the voltage applied to it was

detemined ly the current building up through the resistor at gap breakdown® The vklue of this resistance was kept high so that adequate

voltage was mintained^across the discharge tube for a long tima^ but

it I^d to be low enough to insure a miniirruiii current above 10 ma® A value

of 2 X 10® ohms was found to be satisfactory®. Measurements were made of

the rise time of this voltage by disconnecting it from the discharge

tube^ suppl3Ting the tube with a steady 50 and using either a capa=

citance or resistance divider to connect a srrjall fraction of the voltage

to th® CRO deflecting plate® With -this circuit arrangement the voltage

rises from zero to full value in about 3 microseconds and maintains

nearly full value for several hundred microseconds® When this voltage

was used to supply the discharge tube a very intense electron beam was

established at about the time full voltage was established across the

tube® The beam intensity was even neater than that obtained with a

low voltage pulse as applied above \inder steady discharge conditions

of the tube^ and the intensification lasted much longer - up to at least
An attempt was made to measure the current throu^ iiie discharge

tube while the beam was being established but charging currents caused

by the small stray capacitance of the cathode^ anode and its shield^

masked the current being measux'ede An accurate measurement of the

voltage applied to the discharge tube could not be obtained because

of the uncertain characteristics of resistors used in the divider cir^

cuito The need to keep its inductance low required that the divider

be iTiade of globar or carbon units s All such available resistors were

found to have a very high voltage coefficient (5 percent per KY per cm) a

Efforts to find high resistance units of minimiM inductance that

did not have too high a voltage coefficient were unsuccessfulo A

Wheatstone bridge was set up » using a high voltage pulse in place of

a battery and the CRO deflecting plates for a detector® Wire wound

non«=inductive resistors (zero voltage coefficient) were used in three

arms of the bridge with the resistor being tdsted in the fourth arm®

As many different types and makes of resistors as could be obtained

were tested to determine their voltage coefficients but none were found

with a low enough coefficient to be suitable for a divider® Thus measurera^t difficulties encountered when using this high-resistance surges

voltage divider limited the usefulness of further data that might have

been taken with it®

However^ the results described above^, when full voltage was

suddenly applied to the discharge tube indicated that further work

along this line should be done® Detailed information feb needed as

to what happens in the discharge tube as the voltage across it is

quickly raised from zero to full value (50 KV)® The beam arroeared

to be established within a f@w microseconds and the phenomena, of

interest would probably not Hast more than about 100 microseconds®

Thus the voltage applied should rise quickly to maximum value and re= main nearly constant for about 100 microseconds® Such a voltage can be obtained by using the two lowei' capacitance units of a high-voltage

surge generator discharging through a resistance of about 1000 ohms®

Thus it was apparent that a voltage divider for measuring purposes

could be made up of low resistance non-inductive wire wound units that

would eliminate the difficulties encountered with the high resistance

divider® A schematic wiring diagram of 1he setup that was devised for

further studies is shown in figure 8® An overfiead line was used to

bring the 50 KV from the surge generator to the CRO® Some resistance

is placed in s eries with the line at the sxirge generator and a capacitance to ground at this point was used to adjust the rate of voltage

rise® At the CRO^, the overhead line was connected to ground through a

resistance divider with a high side of 1000 ohms and a low side of

25 ohms^ giving a voltage of correct magnitude for the CRO deflecting

plates® The high side of the divider was connected to the cathode of

the discharge tube through a 10^000 ohm resistance for suddenly applying voltage® The applied voltage could be easily synchronized with the

CRO sweep by using the regular trip circuits of the CRO and surge

generator®
A considerable amount of data was tak^n with this setup under

various conditions in the discharge tube» Under some conditions a

.beam is established as soon as the tube voltage reaches its maximum

valueo The beam builds up to an extremely high intensity in a few

hundredths of a microsecond and stays high for a few microseconds

and then gradually dies outo Under other conditions either no beam

is established or it is delayed an erratic amount (up to 30 micros

seconds) after voltage is appliedo All the factors which might be

thought to affect build=up of the beam were changed but the erratic

behavior still persisted and could not be pinned down to any of the

variables trieda

The most easily controlled variable ip the discharge tube is

gas pressure and effects of changes in gas pressure were thoroughly

invBStigatedo Under steady sthte conditions the discharge is extreme^

ly sensitive to changes in gas pressure^, a satisfactory bean is

attained only over a range in pressure of the order of a fraction of

a micron at a pressure of about 15 microns a At lower pressures no

visible discharge is obtained and at higher pressures 1±ie discharge

current becomes high and unstableo With suddenly applied voltage a

very intense beam is obtained at the pressure yielding a good steady

state besoTio For small increases in pressure a more intense beam is

obtained which lasts longer^ but pressure is increased a little

more the discharge lights up the whole tub@ and apparently draws a very large current TnSiich reduces the voltage applied to the iaibe and

no beam is obtainedo , J£ the pressure is reduced below the normal

steady state value^ a momentary bean can still be established but

the intensily and duration of the beam decrease markedly with pressurso In some cases a very short duration (less than 1 microsecond)

beam was obtained at even the lowest pressure obtainable (about

1 iTiieron)* The erratic behavior of the beam did not appear to depend

solely on the gas pressure although at times when a beam could not

be obtained at one pressure^ changing the pressure caused the beam to

appear

Another variable which at times appeared to affect the erratic

behavior is the distance between the cathode and the anode tube

inside the discharge tube® Changing this distance at times appeared

to make the beam disappear entirely but no definite repeatable effect

of changing this distance could be establisheds

Another factor considered was the effect of the brown coating

of metal oxide which appears on ihe inside of the glass tube after

it has been in operation over a fairly long period,, No direct correlation between the density of this coating and erratic beam bdiavior

could be established®
=10'=

An attempt was made to correlate erratic behavior with moisture

content of the gas in the discharge tube® Both very dry and very

wet air were tried without successful correlationo Neither could

correlation be obtained with the general weather conditions or

idity of the laboratory airo

A factor which at first seemed to affect the erratic behavior

was the condition of the cathodao On some trials a cathode -^diich had

been used for a long period and had an appreciable crater at its

center where the beam originates appeared to always give repeatable

results® A new cathode appeared to give erratic behavior® However^

these tests could not always be repeated with the same restilts®

Since condition of the cathode appeared to have an effect^ a trial

with a cathode of a different metal ms made® A piece of pure silver

was soldered on the end of a cathode rod arii then turned down and

polished* With the silver as the cathode no erratic behavior was noted®

The beam always started within a microsecond, after the attainment of

full voltage and built up to very high intensity within a few hand”

redths of a microsecondo The intensification lasted longer with the

silver cathode^, up to 60 microseconds^ but both the intensity and

duration were found to decrease as the pressure was decreased® The

metal oxide coating on the inside of the ^ass tube builds up veiy

rapidly in use witti a silver cathode and one trial was made by re=> placing the silver cathode with the usual type of alminum cathode

after a heavy coating on the glass had been built up^ using the silver cathode® For this trial the aluminum cathode also gave a good

repeatable intensified beam®

The experiments described above^ with full voltage suddenly

applied^ were carried out using a glass discharge tube® To see if

the glass was in any way responsible for the beam intensification

obtained^ similar experiments were carried out using the glass-metal

discharge tube shown in figure 2^ with the cathode projecting down

into the metal tube® With this simulated '**metal** tube and an alura=

inum cathodej, a beam could not be established by suddenly applying

the voltage® With a silver cathode^, repeatable beams were established

but they differed from those obtained with a glass discharge tube*

Although the initial stages of the developing beam repeated quite well

there wa.s a delay of about 10 microseconds after full voltage was

applied before the beam started® The buildup of beam intensity was

much slowerj, requiring several microseconds® However^ the intensity

and duration were about the same once the beam was established® The

changes in beam intensification and its duration with changes in

pressure were about the same as those already described when a glass

tube was used® These results indicate that the mechanism for estab-=

lishing the discharge is quite different for a metal tube than for

a glass tube® No satisfactory explanation was deduced for the errat<=

ic res\ilts obtained when full voltage is suddenly applied to the

discharge tube®
-11-

IV® Summary of Results

lo A method has been developed for momentarily intensifying the

electron beam obtained from a cold-cathode discharge tube® This momentary intensification is about fifty times its steady state value© The

utilization of this method of beam intensification for obtaining very

high writing speeds with a CB3 has been described in R«Po No© 2231©

2o This intensification phenomena is not dependent to any very

great extent on the gas used in the discharge tube®

3» The material surrounding the discharge at and near the cathode must be a dielectric such as glass and not a conductor if intensification ly superposed small pulses is to be obtained®

U© When full voltage is suddenly applied to the discharge tube

an intensified beam is obtained at times^ but results are usually not

repeatable®

5® A satisfactory theoretical e2q)lanation for this beam intensification phenomena was not obtained® Such an explanation will probably

not be attained until the steac^ state mechanism of the discharge in a

high-voltage cold-cathode tube is completely \mderstood© Although such

discharge tubes have been in use for over thirty years there is still

no esqserimentally verified theory for e^qjlaining their behavior© Continued studies of exactly itfiat happens when full voltage is suddenly

applied to the electrodes might eventually yield a satisfactory theory©

6© The most important objective of this work which was to learn

enou^ about the intensification phenomena so that it could be used to

obtain very high writing speeds with the CRO has been achieved© The

CRO5 with intensificatioHj has already been used in an investigation

of insulator puncture using surges with rates of voltage rise up to

lljOOO KV per microsecondo It is now being used to study front of

wave measuranents on rapidly rising voltage surges©

-3 kv + 3 kv

Figure 1. Wiring diagram showing delay lines used to synchronize CRO sweep with surge generator
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um.’*’-' 'Mr'-
CRO DEFLECTION CHAMBER

Figure 2. Modified discharge tube for producing electron beam

A

0081 +

(A)

is

for

positive

polarity

voltage

pulse,

and

4-2460 V

(B)

is

for

positive

polarity

voltage

pulse.

+

2000 V

u

&0

nJ

(U

(U00

(iu

cn

t3

t3Os

uf

(U 43

rs

i->

(u X!

03aa

ViOOOU

03 o

(U

ViS

00

03 43

03 •Ht3 V

433

4->

(U X)O

Pi 0 oJ 0)

(U c

43 0) rt

+->

X

OOp•

43 43

i-i

•Mo

(D00

OQd

43 X CiO

o3 rd

CO 03 o3 CJ dJ

CO

r*H P

•H 0

CO

•rH X PP

OOp• rH >

43 X P X +-> 0 P X!

•r^

+-» 43

+-> X

r—

CO 00p

u ») <v 0 • rH •H 43

Jh

M

43

CO

X (U -i-> c O +-> (U 43 •4-> P

<4->

u CO • rH

43 n! V •f^ U V

'-M

43 43

p 0 U

rj

13U

p!OO

(U XO

13

(t! X

0) • fHCU

Ph

aJ

0303

0300c

(t 43u

OOc

•iH xtp0

Pi

0303Vuou

ViO

03

CQ PP

positive

polarity

voltage

pulse,

and

+

2700 V

209- ( Xi0) 00u 0) 00

I—

o> V

'Ooc

(6

Xo

(0

CQ • w

U

i) X4-> •iH W O

<M

•Mc

4-> 4>

4)

V

V

kM

VH

T30

:3 •M

4> o

:3CJC• C T30 4) o a

•H 00

4)00Cd

ao 4)

X c

•H

0)

(0

4-»

4; •H

(fi

du

00c u

oo

c: • H

'O

a; •H c

•H TJ 0

00 c a

p 0 (0 Ph c cx 4>

d c ’'S QQ £ 0 4> l-t 4> 0

4->

M

U

u

•rW

4^

4) 0o4)

4) 43 II

CO 43 (0 4) c 0

•4-> 4)

4-J

X CQ • v4 •M • H

d

(A)

is

for

negative

polarity

voltage

pulse,

and



TO

DISCHARGE

TUBE

CATHODE >

li

FIGURE 8

CIRCUIT

USED

FOR

SUDDENLY

APPLYING

VOLTAGE

TO

DISCHARGE

TUBE

TEDE NATIONAL BUMEAU OF STANDARDS

Func!:ions amd Activities

The functions of the National Burean of Standards are set forth in the Act of Congress, March

3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and

maintenance of the national standards of measurement and the provision of means and methods

for making measurements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instroments for testing materiab,

devices, and structures; advisory services to €k)vemment Agencies on scientific and technical

problems; invention and development of devices to serve special needs of the Government; and the

development of standard practices, codes, and specifications. The work includes basic and applied

research, development, engineering, instrum^tati^ testing, evaluation, calibration services, and

various consultation and information services. A major portion of the Bureau’s work is performed

for other Government Agencies, particularly the Department of Defense and the Atomic Energy

Commission. The scope of activities is suggested by the listing of divisions and sections on the

inside of the front cover.

Reports and Publications

The results of the Bureau’s work take the form of either actual equipment and devices or published papers and reports. Reports are issued to the sponsoring agency of a particular project or program. Published papers appear either in the Bureau’s own series of publications or in the

journals of professional and scientific societies. The Bureau itself publishes three monthly periodicals, available from the Government Printing OfSce: The Journal of Research, which presents

complete papers reporting technical investigations; the Technical News Bulletin, which presents

summary and preliminary reports on work in progress; and Basic Radio Propagation Predictions,

which provides data for determining the best frequencies to use for radio communications throughout

the world. There are also five series of nonperiodical publications: The Applied Mathematics

Series, Circulars, Handbooks, Building Materials and Structures Reports, and Miscellaneous

Publications.

Information on the Bureau’s publications can be found in NBS Circular 460, Publications of

the National Bureau of Standards ($1.00). Information on calibration services and fees can be

found in NBS Circular 483, Testing by the National Bureau of Standards (25 cents). Both are

available from the Government Printing Office. Inquiries regarding the Bureau’s reports and

publications should be addressed to the Office of Scientific Publications, National Bureau of Standards, Washington 25, D. C.