NASA/TMm97-206324

RHETT2/EPDM Hall Thruster

Propulsion System Electromagnetic

Compatibility Evaluation

IEPC-97-108

Charles J. Sarmiento and John M. Sankovic

Lewis Research Center, Cleveland, Ohio

Joseph Freitas and Peter R. Lynn

Naval Center for Space Technology, Washington, DC

December 1997

https://ntrs.nasa.gov/search.jsp?R=19980017616 2018-05-11T16:42:52+00:00Z
The NASA STI Program Office... in Profile

Since its founding, NASA has been dedicated to

the advancement of aeronautics and space

science. The NASA Scientific and Technical

Information (STI) Program Office plays a key part

in helping NASA maintain this important role.

The NASA STI Program Office is operated by

Langley Research Center, the Lead Center for

NASA's scientific and technical information. The

NASA STI Program Office provides access to the

NASA STI Database, the largest collection of

aeronautical and space science STI in the world.

The Program Office is also NASA's institutional

mechanism for disseminating the results of its

research and development activities. These results

are published by NASA in the NASA STI Report

Series, which includes the following report types:

TECHNICAL PUBLICATION. Reports of

completed research or a major significant

phase of research that present the results of

NASA programs and include extensive data

or theoretical analysis. Includes compilations

of significant scientific and technical data and

information deemed to be of continuing

reference value. NASA's counterpart of peerreviewed formal professional papers but

has less stringent limitations on manuscript

length and extent of graphic presentations.

TECHNICAL MEMORANDUM. Scientific

and technical findings that are preliminary or

of specialized interest, e.g., quick release

reports, working papers, and bibliographies

that contain minimal annotation. Does not

contain extensive analysis.

CONTRACTOR REPORT. Scientific and

technical findings by NASA-s _onsored

contractors and grantees.

CONFERENCE PUBLICATION. Collected

papers from scientific and technical

conferences, symposia, seminars, or other

meetings sponsored or cosponsored by

NASA.

SPECIAL PUBLICATION. Scientific,

technical, or historical information from

NASA programs, projects, and missions,

often concerned with subjects having

substantial public interest.

TECHNICAL TRANSLATION. Englishlanguage translations of foreign scientific

and technical material pertinent to NASA's

mission.

Specialized services that complement the STI

Program Office's diverse offerings include

creating custom thesauri, building customized

data bases, organizing and publishing research

results.., even providing videos.

For more information about the NASA STI

Program Office, see the following:

• Access the NASA STI Program Home Page

at http:/Iwww.sti.nasa.gov

• E-mail your question via the Internet to

help@sti.nasa.gov

• Fax your question to the NASA Access

Help Desk at (301) 621-0134

• Telephone the NASA Access Help Desk at

(301) 621-0390

Write to:

NASA Access Help Desk

NASA Center for AeroSpace Information

800 Elkridge Landing Road

Linthicum Heights, MD 21090-2934
NASA/TMm97-206324

RHETT2/EPDM Hall Thruster

Propulsion System Electromagnetic

Compatibility Evaluation

IEPC-97-108

Charles J. Sarmiento and John M. Sankovic

Lewis Research Center, Cleveland, Ohio

Joseph Freitas and Peter R. Lynn

Naval Center for Space Technology, Washington, DC

Prepared for the

25th International Electric Propulsion Conference

sponsored by the Electric Rocket Propulsion Society

Cleveland, Ohio, August 24-28, 1997

National Aeronautics and

Space Administration

Lewis Research Center

December 1997
NASA Center for Aerospace Information

800 Elkridge Landing Road

Linthicum Heights, MD 21090-2934

Price Code: A03

Available from

National Technical Information Service

5287 Port Royal Road

Springfield, VA 22100

Price Code: A03
RHETT2/EPDM HALL THRUSTER PROPULSION SYSTEM

ELECTROMAGNETIC COMPATIBILITY EVALUATION

Charles J. Sarmiento and John M. Sankovic

National Aeronautics and Space Administration

Lewis Research Center

Cleveland, Ohio

Joseph Freitas and Peter. R. Lynn

Naval Research Laboratory

Naval Center for Space Technology

Washington, D.C.

ABSTRACT

Electromagnetic compatibility measurements were obtained as part of the Electric Propulsion

Demonstration Module (EPDM) flight qualification program. Tests were conducted on a Hall

thruster system operating at a nominal 660W discharge power. Measurements of conducted

and radiated susceptibility and emissions were obtained and referenced to MIL-STD-461C.

The power processor showed some conducted susceptibility below 4kHz for the magnet

current and discharge voltage. Radiated Susceptibility testing yielded a null result. Conducted

emissions showed slight violations of the specified limit for MIL-461C CE03. Radiated emissions

exceeded the RE02 standard at low frequencies, below 300 MHz, by up to 40 dB[tV/m/MHz.

INTRODUCTION

Over the past several years the Ballistic

Missile Defense Organization (BMDO)

through the National Aeronautics and Space

Administration has sponsored the development

of Hall thruster technology under the Russian

Hall Electric Thruster Technology (RHETT)

program. The last phase of the program

(RHETT2) was to bring the technology to

flight readiness. The Naval Research

Laboratory (NRL) has the synergistic goal of

demonstrating new space technologies with

high payoff to the government. Under NRL's

Electric Propulsion Demonstration Module

(EPDM) program, NRL sought to demonstrate

new electric propulsion systems on orbit. In

1996 the two programs were essentially

combined with BMDO sponsoring the

propulsion system hardware, NRL serving as

the integrator, and NASA Lewis Research

Center (LeRC) responsible for hardware

development and qualification testing. 1

The EPDM flight propulsion system consists of

a low-power Hall thruster with cathode, a

power processing unit (PPU) to operate the

thruster, an analog interface unit (AIU) to

operate the heaters and provide the interface

between PPU and spacecraft, and a xenon

propellant system. This propulsion system

operates at 660 W into the discharge. The

mission goal is to demonstrate multiyear

operation with performance of both orbitraising and stationkeeping functions. 1'2 The

propulsion system was subjected to a battery

of verification tests, including thrust

measurement, vibration, magnetic dipole

measurement, thruster plume/spacecraft

interaction, thermal and electromagnetic

compatibility (EMC).

Because of the added power electronics and

presence of a plasma discharge in the majority

of electric propulsion (EP) systems,

electromagnetic compatibility is a significant

perceived risk for potential users of this

technology. Previous EMC measurements have

been performed on various EP systems

including arcjets, magnetoplasmadynamic

thrusters, and Hall thrusters. 1'35 Conducted

emissions and susceptibility are usually a

function of the power processor design and

testing typically consists simply of verifying

compliance with design specifications.

Radiated emissions for EP devices are usually

dominated by broadband noise from the

plasma discharge and often exceed common

spacecraft specifications, especially in the

<100 MHz frequency range. This paper

summarizes the electromagnetic compatibility

measurements on the EPDM flight propulsion

system. Testing was conducted to insure

compatibility of the propulsion system with its

operational environment and self

compatibility. Both conducted and radiated

NASA/TM--97-206324 1
susceptibilitymeasurements wereobtainedon

the hardwarealong with conductedand

radiatedemissionsmeasurements.

APPARATUS AND PROCEDURE

Electromagnetic compatibility testing was

performed in accordance to MIL-STD-462 in

order to determine compliance to MIL-STD461C. Table I lists the conducted and radiated

susceptibility and emissions tests addressed in

whole or in part by this study.

Conducted susceptibility tests CS01 and CS02

were performed on the power processor by the

manufacturer, Primex Aerospace Co. The

EPDM system is powered by two separate

lines: a primary circuit which powers the

thruster functions and an auxiliary circuit for

control and data handling. Both the primary

power and the auxiliary power inputs were

tested from 30 Hz to 100 Mhz. During testing

the power supply was operated into a resistive

load and the discharge voltage along with both

inner and outer magnet currents were

monitored. In addition, operation of the heater

current at all current settings was verified.

Radiated susceptibility, RS03, was conducted

at the system level at NASA LeRC. The

hardware set-up inside the vacuum facility is

shown in Figure 1 with all flight harnesses

connected. The testing was conducted using a

signal generator input to a rf power amplifier

connected to a horn. The signal generator was

swept from 2 GHz to 2.4 GHz while

maintaining a field strength of 25 V/m at the

test hardware. During these sweeps the

propulsion system was operated in five

different modes and monitored for any

degradation. The following modes were tested:

(1) through (3) cathode heater levels, no

discharge; (4) Thruster operating at 660 W

discharge power, and (5) Auxiliary power on,

primary power off.

Conducted and radiated emission tests CE01,

CE03, RE01, and RE02 were also performed at

the system level at NASA LeRC. Conducted

emissions were measured from 30 Hz to

50 MHz on the input power lines to the EPDM

system. Radiated measurements were obtained

from 14 kHz to 18 Ghz. A photograph of the

test set-up is shown in Figure 1. Antennas used

for the radiation emission testing were located

1 m from the hardware arranged in a

semicircle behind the thruster as detailed in

Figure 2. Frequency ranges for the antennas

are provided in Table 11. The antennas were

covered with a Kapton "tent" to prevent

plasma impingement. The tent and hardware

were positioned in NASA LeRC Vacuum

Facility 5 as shown in Figure 3. A spectrum

analyzer with preselector (fronted by low noise

amplifiers for 1-18 GHz) was used as the EMI

test receiver. Separate broadband and

narrowband sweeps were performed with the

data acquisition/control software (Table II)

which employed a BB/NB signal

discrimination algorithm based on MIL-STD462. This processing eliminated clearly NB

signals from the BB data. Broadband levels

were normalized to a 1 MHz impulse

bandwidth assuming worstcase, coherent type

noise; that is, with a 201og(1MHz/RBi)

relation.

RESULTS

Conducted Susceptibility. The power processor

showed no evidence of unacceptable

susceptibility (such as shutdown or cycling)

for both CS01 and CS02 on the primary and

auxiliary input lines. Furthermore, no effects

were observed on the monitored cathode

heater currents, discharge voltage, and magnet

currents for CS01 and CS02 on the auxiliary

input or CS02 on the primary input. However,

small effects were noted for CS01 injection on

the primary input line. The results of CS01 on

the primary power input are presented in

Table III. Below 4kHz, a ripple corresponding

to the injected frequency was present on the

magnet currents and discharge voltage. For

some of the CS01 testing the injection

equipment could not provide full power into

the PPU, so estimates of the effects at full

spec levels are provided in Table 11I. The

effect on the magnet current was a maximum

of 11.2% ripple at 30 Hz decreasing to zero by

4kHz. Similarly the effect on the discharge

voltage was a maximum of 4.7% at 60 Hz,

decreasing to zero by 4kHz.

Radiated Susceptibility. Tests were only

performed from 2 to 2.4 GHz, the frequency

band of major interest to NRL for the flight

application. Over this range, no effect of the

radiation was observed on any of the EPDM

operating parameters. Wider frequency

coverage was precluded by equipment and

time limitations.

NASA/TM--97-206324 2
Conducted Emissions. The results of CE01

from 30 Hz to 15 kHz are provided in Figure 4

for the primary power lead and in Figure 5 for

the auxiliary power. Both the primary power

and the auxiliary power lines were in

compliance with MIL-STD-461C. Similarly,

the results of CE02 from 15 kHz to 50MHz are

presented in Figure 6 and Figure 7 for the

primary and auxiliary power lines,

respectively. The auxiliary line showed

emission levels above specified limits from

approximately 300 kHz to 2 MHz and from 10

to 15 MHz by up to 15 dB_tA/MHz. Selected

features of the spectrum were scrutinized by

examination of the temporal variation of

emission at the given frequency using various

bandwidths. Observed pulse repetition

frequencies (PRFs) of each emission feature

were noted. PPU switching noise was

associated with -55 kHz PRFs (and harmonics

thereof), but could also have been noted as

~27 kHz due to unequal pulse amplitudes. The

primary line exceeded specification from

400kHz to 3 Mhz by up to 25 dB_tA/MHz,

results similar to those obtained by the PPU

manufacturer while conducting CS02 on the

PPU operation into a load resistor.

Radiated Emissions. The results of the

magnetic field radiated emissions, RE01, from

30 Hz to 2 MHz are provided in Figure 8. The

data show little effect of the thruster on the

measurement below 2 kHz. Above that range

up to 2 MHz, the emission level ranges from

60 to 35 dBpT. The results of the electric field

radiated emissions, RE02, from 14 Hz to

18 GHz are presented in Figure 9 for the

broadband and Figure 10 for narrowband. The

spectra display a high level of incoherent

(random) broadband noise at low frequencies,

characteristic of EP plasma devices. Indeed

emissions exceeded limits below 300 MHz by

up to 40 dBuVlm/MHz. This noise rolled off

with increasing frequency and was replaced by

coherent (impulsive) noise extending into the

Ghz range. Generally, the low frequency

emissions do not cause great concern as most

spacecraft employ EMC measures (e.g. cable

shielding) which readily inhibit interference at

such frequencies. Of greater concern are the

noise levels at radio/microwave

communication frequencies, particularly the

uplink bands. Emissions at these Ghz

frequencies were typically below 40

dB_tV/m/MHz.

CONCLUDING REMARKS

Flight qualification of the EPDM propulsion

system included verifying system compliance

to electromagnetic compatibility

specifications to ensure compatibility with the

spacecraft environment and self compatibility.

Of major concern with electric propulsion

systems is verification of proper power

processor design to comply with conducted

and radiated standards and radiated emissions

from the plasma discharge.

MIL-STD-461C was used as the reference

standard. Conducted susceptibility

measurements on the power processor showed

a small effect below 4kHz on the discharge

voltage and magnet current. Radiated

susceptibility measurements in the

communication band of 2-2.4 GHz gave a null

result. Conducted emissions on the primary

and auxiliary power lines violated the standard

by various degrees from 300 kHz 15 MHz.

Radiated emissions for magnetic field were in

compliance while electric field measurements

were up to 40 dBuV/m/MHz above the limit

below 300 MHz.

REFERENCES

1. Sankovic, J.M., Caveny L.H., and Lynn, P.R.

"The BMDO Russian Hall Electric Thruster

Technology (RHETT) Program: For Laboratory

to Orbit," AIAA-Paper-97-2917, July 1997.

2. Lynn, P.R., et al., "RHETT/EPDM Flight

Hall Thruster System," Proceedings of the

25nd International Electric Propulsion

Conference, August 1997, to be published as

IEPC-97.

3. Zafran, S., "Hydrazine Arcjet Propulsion

Integration Testing,"IEPC-91-013, Proceedings

of the 22nd International Electric Propulsion

Conference, Oct. 1991.

4. Pencil, E.J., Sarmiento, C.J., Lichtin, D.A.,

Palchefsky, J.W., and Bogorad, A.L., "Low

Power Arcjet System Spacecraft Impacts,"

AIAA-Paper-93-2392 (also NASA TM

106307), June 1993.

5. Ijichi, K., Yoshida, T., Kudo, I., and Kuriki,

K., "Radiated Emission Noise of the Plasma,"

AIAA-Paper-82-1883, Nov. 1982.

NASA/TM--97-206324 3
Table I. Summary of tests conducted

C$02 Conducted susce_!bi_, ,1power leads, 50 kHz to 100 MHz

RS03 ........................... [Ra_tiated susceptibiti_, electric field, 14 kHz to 18 GHz

Table II. Antenna/spectrum analyzer configurations

_DIA'rE6'MEASd_EMENTS-RE02 Natr#wb_r_d (N_)._._ Bro_dbar,d (P,B)

5;S:! .... PFI-6a ,,,75 ......... lk 300 lok $ok

1-2 PR-B4 75 Ik 300 ...... 1ok 30k ,,,

2-4 PR-BS,, 75 1,k 30,0 1Ok 30k

i4-S PRTB,,_, [,7'5 '3k lk 30k .... ,00k

ie*16 " pR-B7 78 3k lk _0k,, "lOOk

16_-32 PR-B,_ .......... 70 3k ..... 1_ 30t{ lOOk

32-200 B¢¢3)_i¢_l ...... 70 ...... lQk 3'k , lOOk" 300k

_0.£,350, "BB o 10 ........ 30k ..........j.lOk _oek, 18 _

3#.p.._ooo ......BLP .. , _s 3o_ _ok ........ _oQ_f lM ........

t ..... ! ...... , ......

1000-20Q0 ..... P:_LP 95 "lOOk i30k 3M , , .'3M

20oo-400o .......... w_ LNAs 95 .... lOgk .'30k 3M .. 3M

400o-8000 , Os _oek 3qk 3k_ 3_._

sooo.4sooo _ _oo_ _Ok _ _M ....

RAD_ATEDMEASUREMENT_E01 _ ilt'_'a_'tcrwtmnd (N B) "1 _to_dband {BB} .J

I_0.... 1,,_o I ,_.... 1 ....1 -]

_b.oo 5 I lBg........I._O I_0 I I I

I _,,_b05-0,05 .........JZ.c_ _ .... I1O_ _N/#. INIA I

io4s-o.._"] " I_o _ I I

__._uR_ ...... I_-_,,_,,_ !N'_iI_,_'_.__): :_

10.0004-0:015 IBCP S_o ..... 180 ]#O .. 1300 ....IN/A |NfA ......... I

_SN{)uc'rEo MF.,ASUREMENTS-CEO .... [Nan'owband (N_).,.,[Bro,_d_x_r,d (aB) i

IF_eq. Ra_._ (Maz)lPmbe RL (dB_V) RBiHz I VB (Hz'_IRB (az) V8 _Hz_

("661_-0"i*J' |13CP_i_ t;'5 ...... 13k " 13o'o ' ISk ::_

_.(o IBcP ;'i'_" I?_ ...... I_o_ .... I_k 13o,. lgook ..I

Abbr_v_atior.s:

BOP: ,l_road,band _,_rter_t ,Erobe

8LP: _{g Log J_cfiedk; Dip{de

SLP: _maII Log Pedod_c Oi#ole

LN.k Low _.¢qse &mpltlier

F{L; $pec#tm_ A_'_.alyzer_efetence Level

R|3: Re_olutien _andwid_h

VB: yidoo (post4e_ection) .8.ar_dwid_

Table III. Conducted susceptibility results

NASA/TM--97-206324 4
TANK S

WALL--_

(Steel)

_ a

H

Fig. 1. EPDM flight hardware undergoing

EMC testing at NASA LeRC

Fig. 2. Antenna placement for radiated

emissions measurements

r-.-.Test Platform with Antenna Array

!

'_....................... _{L_'.:_'_....!. .............................. _........_:_ ................................ ,............................... ............

............ 4,3 m ..........

$

N

\

Fig. 3.

. ., [... I:_._. AC,_J

Ter_ --.!_ _ F 1_SS TAL

' : ,'_.. Xe T_k w.

• _--- 8.1 m

................................................................................... 16,5

4.6 m

m .................................................................. _---0.gin

EMC test pallet location in NASA LeRC Vacuum Facility 5

Fig. 4(a). Background

Fig. 4.

Fig. 4(b). Power on

Auxiliary power line conducted emissions from 30 Hz to 15 kHz, CE0I

NASA/TMu97-206324 5
4

_0

Fig. 7(a). background, broadband

i iii_ ......

_ _t_al ....

it....................

,o_ .....L--..L .

w?_lll

i:_,r_:_,_ _, _

Fig. 7(b). Power on, broadband

Fig. 7. Primary power line conducted emissions from 15 kHz to 50 MHz, CE03 (cont.)

NASA/TM--97-206324 6
7f_ ....i.....

i

3_

Fig. 7(c). Background, narrowband

Fig. 7. Primary power line

t

--- i -" i--#- _ .............. :Y;7:T:: ..............:.....

_° _ 1111_ [-rTt111_.Tlqllt_h;;

'° Z: []]ili........ [_]JL_I,_

• e_ [.................. :i ........................................................... "_-- ..... '_

Fig. 7(d). Power on, narrowband

conducted emissions from 15 kHz to 50 MHz, CE03

"_'_ __i<. "_"" tTT T"__s:#;;;"i-tgT-_;=;[di:_ ..........

...................... "_-- S::tttt11 i _ ]4. _,. _i4_k,,,,, ........

....'..... l!i[

i..q.!........................

_'*" i" il _.++, ";#. .....

-- _t iii i ' '.....

Fig. 8(a). Background Fig. 8(b). Thruster on

Fig. 8. Radiated emissions, magnetic field, 30 Hz to 50 kHz, RE01

_-,._..._.,_,_ ..... .__..,._.._ \

: I

[ ! i

_!_, .[_._.! ........................................

Fig. 9(a). Background, 14 KHz-32 MHz

_:¢" iiii]_ _: _._i-'_'["!_ "_'_'i'_iiiiilr i __': _,,_e _:,_- _ _k__ _ "_il

[ I_; ",_!,1 14..(_>*.... _)_ _............. :r.............. !.............

[....................... [i............................ +...................................... t'_

....... V _°"" "+ "**-_

................................................................. _:_!_:_:.X,._!_.............................................................

Fig. 9(c). Background, 32 MHz-1 GHz

-tl_i_ ................... _-¢_ _ _ -]i

[L]Z]Z]!,.:44........................... :............. _¢--!:

_;_!"'-+"_X ......... _ *...... ÷.........

! i i I

..........: ....................... :..... __ _

_'_X_:_:_:v [_'_ ...........

Fig. 9(d). Thruster on, 32 MHz-1 GHz

Fig. 9. Radiated emissions, electric field, broadband, RE02 (cont.)

NASA/TM--97-206324 7
Fig.9(e).Background, 1 GHz-18GHz

i_ } }

2

_................... _................ !............ _--i-t_ li_

Fig. 9(f). Thruster on, 1 GHz-18 GHz

Fig. 9. Radiated emissions, electric field, broadband, RE02

Fig. 10(e). Background, 1 GHz-18 GHz

i!..........

._°tEilli[illi!illl ....

_[jt_.._:_,-_ ..........

_e_: _,_ _ /

• ,t:,...,..-+-?_- : _.

.............i......... i i .........

Fig. 10(f). Thruster on, 1 GHz-18 GHz

Fig. 10. Radiated emissions, electric field, narrowband, RE02.

NASA/TM--97-206324 8
REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources,

gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this

collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson

Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503.

1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED

December 1997 Technical Memorandum

4. TITLE AND SUBTITLE 5. FUNDING NUMBERS

RHETT2/EPDM Hall Thruster Propulsion System Electromagnetic

Compatibility Evaluation

6. AUTHOR(S)

Charles J. Sarmiento, John M. Sankovic, Joseph Freitas, and Peter R. Lynn

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Lewis Research Center

Cleveland, Ohio 44135-3191

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Washington, DC 20546-0001

WU-632-1B-1B-00

8. PERFORMING ORGANIZATION

REPORT NUMBER

E-10997

10. SPONSORING/MONITORING

AGENCY REPORT NUMBER

NASA TM--97-206324

IEPC-97-108

11. SUPPLEMENTARY NOTES

Prepared for the 25th International Electric Propulsion Conference sponsored by the Electric Rocket Propulsion Society,

Cleveland, Ohio, August 24-28, 1997. Charles J. Sarmiento and John M. Sankovic NASA Lewis Research Center;

Joseph Freitas and Peter R. Lynn, Naval Research Laboratory, Naval Center for Space Technology, Washington, D.C.

Responsible person, Charles J. Sarmiento, organization code 5430, (216) 977-7427.

12a. DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified- Unlimited

Subject Categories: 20 and 15 Distribution: Nonstandard

This publication is available from the NASA Center for AeroSpace Information, (301) 621-0390.

12b. DISTRIBUTION CODE

13. ABSTRACT (Maximum 200 words)

Electromagnetic compatibility measurements were obtained as part of the Electric Propulsion Demonstration Module

(EPDM) flight qualification program. Tests were conducted on a Hall thruster system operating at a nominal 660W

discharge power. Measurements of conducted and radiated susceptibility and emissions were obtained and referenced to

MIL-STD-461C. The power processor showed some conducted susceptibility below 4kHz for the magnet current and

discharge voltage. Radiated susceptibility testing yielded a null result. Conducted emissions showed slight violations of the

specified limit for MIL-461C CE03. Radiated emissions exceeded the RE02 standard at low frequencies, below 300 MHz,

by up to 40 dBIxV/m/MHz.

14. SUBJECT TERMS

Electromagnetic interference; EMI; Electromagnetic compatibility; EMC;

Electric propulsion; Hall thrusters; Thruster with anode layer

17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION

OF REPORT OF THIS PAGE OF ABSTRACT

Unclassified Unclassified Unclassified

NSN 7540-01-280-5500

15. NUMBER OF PAGES

14

16. PRICE CODE

A03

20. LIMITATION OF ABSTRACT

Standard Form 298 (Rev. 2-89)

Prescribed by ANSI Std. Z39-18

298-102