Celia S Chari, Richard R Hofer, Bryan W McEnerney, Steven M Arestie, Robert B Lobbia, Colleen M Marrese-Reading, Katherine T Faber
{"title":"Evaluation of Graphite/h-BN Bimaterials for Electric Propulsion.","authors":"Celia S Chari, Richard R Hofer, Bryan W McEnerney, Steven M Arestie, Robert B Lobbia, Colleen M Marrese-Reading, Katherine T Faber","doi":"10.1007/s44205-025-00126-0","DOIUrl":"https://doi.org/10.1007/s44205-025-00126-0","url":null,"abstract":"<p><p>The performance of an innovative dielectric bimaterial is assessed for use in Hall-effect thrusters. The bimaterial consists of a structural body of graphite with a converted surface layer of hexagonal boron nitride (h-BN). The bimaterial couples the dielectric behavior and low emissivity of h-BN at its surface, with the thermal shock resistance and machinability of graphite at its core. In this paper, the performance of graphite/h-BN bimaterials synthesized from liquid-phase and vapor-phase carbothermic reactions of B<sub>2</sub>O<sub>3</sub> in nitrogen is compared and evaluated against the state-of-the-art wall material, bulk h-BN. Graphite/h-BN bimaterials synthesized through vapor-phase carbothermic reactions are shown to perform comparatively better than bimaterials synthesized through liquid-phase carbothermic reactions. The erosion rate of vapor-phase grown h-BN layers is similar to that of bulk h-BN with a sputtering yield of 0.021 mm<sup>3</sup>/C for xenon ions at 300 V.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s44205-025-00126-0.</p>","PeriodicalId":73724,"journal":{"name":"Journal of electric propulsion","volume":"4 1","pages":"31"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12058926/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144047984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Plume divergence characterization for electric propulsion via standard deviation and emittance.","authors":"McKenna J D Breddan, Richard E Wirz","doi":"10.1007/s44205-025-00113-5","DOIUrl":"10.1007/s44205-025-00113-5","url":null,"abstract":"<p><p>Electric propulsion systems require careful consideration of plume divergence and evolution over a range of operating conditions and environments. Existing means of describing plume divergence such as outlines, plume profiles, and snapshots of the plume are dominated by outlier particles and do not provide reliable or quantitative insight. Proposed herein are two novel methods for describing plume divergence using <i>standard deviation</i> and <i>emittance</i> to provide quantitative insight of the collective behavior of plume species. Furthermore, the emittance metric from the particle accelerator community is shown to accurately describe plume evolution in a two-dimensional position and momentum angle space. Cross-sectional emittance measurements are used to display the presence of non-Hamiltonian forces in plume evolution, namely stochastic Coulomb collisions between neighboring particles. Finally, full-plume emittance diagrams are demonstrated as a means of identifying when an electric propulsion plume has reached steady state.</p>","PeriodicalId":73724,"journal":{"name":"Journal of electric propulsion","volume":"4 1","pages":"11"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11860994/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143525193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Richard R Hofer, Jacob B Simmonds, Dan M Goebel, Joel M Steinkraus, Adele R Payman
{"title":"The H10 high power density hall thruster.","authors":"Richard R Hofer, Jacob B Simmonds, Dan M Goebel, Joel M Steinkraus, Adele R Payman","doi":"10.1007/s44205-025-00129-x","DOIUrl":"https://doi.org/10.1007/s44205-025-00129-x","url":null,"abstract":"<p><p>Magnetic shielding technology has extended the operating life of Hall thrusters to timescales enabling them to expand beyond missions in Earth orbit, which typically require less than 10 kh of operation, to deep-space missions requiring 10-30 kh of operation. While this has expanded potential mission capture, the specific impulse of flight Hall thrusters is still less than 2,000 s, which can limit their use on trajectories requiring velocity change greater than 10 km/s. To expand mission capture further, specific impulses greater than 3,000 s are needed over wide power throttling ratios. Towards those ends, JPL has developed a low-mass, 10-kW class, 3,000 s specific impulse Hall thruster that has demonstrated a 2:1 power throttling ratio at 800 V (~ 3,000 s specific impulse), efficiencies greater than 50% over 6:1 power throttling, and a 50:1 power throttling ratio over 0.2-10 kW. Thermal steady-state operation was reached at 15 kW, and a maximum operating power of 20 kW was briefly demonstrated. To achieve this performance requires novel approaches that can operate at power densities significantly exceeding the state-of-the-art. High power density operation is achieved in the H10 Hall thruster with an integrated, conducting wall, magnetically shielded discharge chamber assembly combined with a passive, multi-zone heat rejection system. Testing has demonstrated peak performance at 800 V, 10 kW of 457 mN thrust, 3400 s specific impulse, and an efficiency of 76%. The H10 represents a new class of high-power density Hall thrusters, enabling next generation robotic science and human exploration missions.</p>","PeriodicalId":73724,"journal":{"name":"Journal of electric propulsion","volume":"4 1","pages":"35"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12075345/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144082658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ion current and energy in the magnetic arch of a cluster of two ECR plasma sources.","authors":"C Boyé, J Navarro-Cavallé, M Merino","doi":"10.1007/s44205-025-00100-w","DOIUrl":"10.1007/s44205-025-00100-w","url":null,"abstract":"<p><p>The feasibility of a novel 'magnetic arch' topology for controlled contactless plasma beam acceleration is experimentally demonstrated using a pair of coaxial electron cyclotron resonance sources with opposing magnetic polarities, such that their respective magnetic nozzles connect to form a closed-line configuration. Retarding potential analyser measurements are taken for a single source and the two sources with the same and opposing polarities, as well as no applied magnetic field, showing that the magnetic arch yields higher maximum ion current and lower plume divergence angle than other alternative configurations, albeit the most probable ion energy is lower than for a single magnetic nozzle, in agreement with existing models. This validation paves the way to clustering magnetic-nozzle-based plasma thrusters for space propulsion.</p>","PeriodicalId":73724,"journal":{"name":"Journal of electric propulsion","volume":"4 1","pages":"10"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11861235/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143525177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Steven M Arestie, Colleen M Marrese-Reading, Saba Z Shaik
{"title":"Ionic liquid electrospray beam target performance characterization.","authors":"Steven M Arestie, Colleen M Marrese-Reading, Saba Z Shaik","doi":"10.1007/s44205-025-00121-5","DOIUrl":"10.1007/s44205-025-00121-5","url":null,"abstract":"<p><p>Electrospray thruster ground testing, with well understood facility effects, is of critical importance to qualify the technology for long duration flight missions. While there has been substantial work to understand the beam physics and plume dynamics of electrospray thrusters and the implications thereof on performance and lifetime, work to understand the impact of facility effects has been neglected until recently. Interactions between an electrospray plume and the vacuum chamber test facility have implications on both performance and lifetime. Therefore, any effort to characterize electrospray thruster performance and lifetime must be done so with an understanding of facility effects. In some ways, this is no different than the significant investment that has been made to understand the facility effects for plasma thruster testing. However, there are different challenges with the management of positively charged, negatively charged, and neutral propellant particles across a distribution of particle charge and mass when testing electrospray thrusters in a vacuum chamber. The focus of this paper is to characterize the significance of secondary particles from the impact of ionic liquid electrosprays with a beam target, and the influence of a novel beam target design and biasing. Results on secondary current and mass flux measurements are presented with some initial results on secondary time-of-flight measurements from the beam target. Additionally, beam target modeling results are presented to support the experiments and interpretation of the results. The results revealed secondary particles with an average charge-to-mass ratio as low as 31 C/kg, and that an improperly biased beam target, or no beam target, can artificially inflate emitted current due to electron back streaming by as much as 20%. The experimental and modeling results suggest an optimized beam target and screen voltage of -100 V and -200 V, respectively. If no consideration of facility effects is included in testing electrospray thrusters, performance, reliability, and lifetime can be adversely affected, and premature thruster failure may result. The work presented here improves our understanding of facility effects and our capabilities to mitigate them to successfully qualify and acceptance test electrospray thrusters for flight.</p>","PeriodicalId":73724,"journal":{"name":"Journal of electric propulsion","volume":"4 1","pages":"22"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11961542/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Collin Whittaker, Steven Arestie, Colleen Marrese-Reading, Benjamin Jorns
{"title":"Characterization of a 10 W class electrospray array thruster.","authors":"Collin Whittaker, Steven Arestie, Colleen Marrese-Reading, Benjamin Jorns","doi":"10.1007/s44205-025-00114-4","DOIUrl":"10.1007/s44205-025-00114-4","url":null,"abstract":"<p><p>A porous conical type electrospray array thruster consisting of 6102 individual emitters is operated at up to 13.3 W power. The design and manufacture of the thruster are described, including its porous glass emitter chip and metallized ceramic extractor chip. A precision mass balance mounted inside a bell jar is used to directly measure the thrust, specific impulse, and efficiency in negative polarity, from <math><mrow><mn>42</mn> <mo>±</mo> <mn>0.5</mn> <mspace></mspace> <mi>μ</mi></mrow> </math> N, <math><mrow><mn>1050</mn> <mo>±</mo> <mn>26</mn></mrow> </math> s, and <math><mrow><mn>57</mn> <mo>±</mo> <mn>1.9</mn></mrow> </math> % at <math><mrow><mo>-</mo> <mn>1000</mn></mrow> </math> V and 0.38 W to <math><mrow><mn>174</mn> <mo>±</mo> <mn>0.5</mn> <mspace></mspace> <mi>μ</mi></mrow> </math> N, <math><mrow><mn>420</mn> <mo>±</mo> <mn>2</mn></mrow> </math> s, and <math><mrow><mn>21</mn> <mo>±</mo> <mn>0.3</mn></mrow> </math> % at <math><mrow><mo>-</mo> <mn>1300</mn></mrow> </math> V and 1.7 W. Additional negative polarity experiments in a 2 meter vacuum facility demonstrate powers from order 1 <math><mi>μ</mi></math> W to over 10 W, spanning 7 orders of magnitude. Power and performance measurements were not repeated for positive mode operation, as this was found to induce arcing between the emitter and extractor electrodes at 1400 V and above. The drop in efficiency from <math><mrow><mo>-</mo> <mn>1000</mn></mrow> </math> V to <math><mrow><mo>-</mo> <mn>1300</mn></mrow> </math> V operation in the bell jar is discussed within the context of facility effects, and secondary charged particle flux to the thruster is identified as a likely contributor. Finally, the performance of the thruster is considered relative to scaling electrospray systems to higher power robustly.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s44205-025-00114-4.</p>","PeriodicalId":73724,"journal":{"name":"Journal of electric propulsion","volume":"4 1","pages":"20"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11947065/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143756326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Design of a power processing unit with integrated telemetry for a vacuum arc thruster as part of the SeRANIS mission","authors":"Roman Forster, Michal Szulc, Jochen Schein","doi":"10.1007/s44205-024-00074-1","DOIUrl":"https://doi.org/10.1007/s44205-024-00074-1","url":null,"abstract":"","PeriodicalId":73724,"journal":{"name":"Journal of electric propulsion","volume":"3 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141686432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multimodal electrospray thruster for small spacecraft: design and experimental characterization","authors":"P. Mallalieu, Manish Jugroot","doi":"10.1007/s44205-024-00075-0","DOIUrl":"https://doi.org/10.1007/s44205-024-00075-0","url":null,"abstract":"","PeriodicalId":73724,"journal":{"name":"Journal of electric propulsion","volume":"1 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141704347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jacob A. Gottfried, Seth Antozzi, Jon Stienike, Seth J. Thompson, John D. Williams, A. Yalin
{"title":"Temporally resolved relative krypton neutral density during breathing mode of a hall effect thruster recorded by TALIF","authors":"Jacob A. Gottfried, Seth Antozzi, Jon Stienike, Seth J. Thompson, John D. Williams, A. Yalin","doi":"10.1007/s44205-024-00070-5","DOIUrl":"https://doi.org/10.1007/s44205-024-00070-5","url":null,"abstract":"","PeriodicalId":73724,"journal":{"name":"Journal of electric propulsion","volume":"104 29","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140986036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Kiefer, K. Keil, K. Holste, P. J. Klar, R. Thüringer
{"title":"Analysis of the radiated emission of an ECR thruster with magnetic nozzle in terms of its EMC","authors":"F. Kiefer, K. Keil, K. Holste, P. J. Klar, R. Thüringer","doi":"10.1007/s44205-024-00069-y","DOIUrl":"https://doi.org/10.1007/s44205-024-00069-y","url":null,"abstract":"","PeriodicalId":73724,"journal":{"name":"Journal of electric propulsion","volume":"7 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141021821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}