A Design of Solar Proton Telescope for Next Generation Small Satellite

손종대,오수연,이유,민경욱,이대영,선종호 한국우주과학회 2012 Journal of Astronomy and Space Sciences Vol.29 No.4

The solar proton telescope (SPT) is considered as one of the scientific instruments to be installed in instruments for the study of space storm (ISSS) which is determined for next generation small satellite-1 (NEXTSat-1). The SPT is the instrument that acquires the information on energetic particles, especially the energy and flux of proton, according to the solar activity in the space radiation environment. We performed the simulation to determine the specification of the SPT using geometry and tracking 4 (GEANT4). The simulation was performed in the range of 0.6-1,000 MeV considering that the proton, which is to be detected, corresponds to the high energy region according to the solar activity in the space radiation environment. By using aluminum as a blocking material and adjusting the energy detection range, we determined total 7 channels (0.6~5, 5~10, 10~20, 20~35, 35~52, 52~72, and >72 MeV) for the energy range of SPT. In the SPT, the proton energy was distinguished using linear energy transfer to compare with or discriminate from relativistic electron for the channels P1-P3 which are the range of less than 20 MeV, and above those channels, the energy was determined on the basis of whether silicon semiconductor detector (SSD) signal can pass or not. To determine the optimal channel, we performed the conceptual design of payload which uses the SSD. The designed SPT will improve the understanding on the capture and decline of solar energetic particles at the radiation belt by measuring the energetic proton.

Conceptual Design of a Solid State Telescope for Small scale magNetospheric Ionospheric Plasma Experiments

손종대,이재진,조경복,이종길,황정아,박재흥,곽영실,박원기,남욱원,독고경환 한국우주과학회 2018 Journal of Astronomy and Space Sciences Vol.35 No.3

The present paper describes the design of a Solid State Telescope (SST) on board the Korea Astronomy and Space Science Institute satellite-1 (KASISat-1) consisting of four [TBD] nanosatellites. The SST will measure these radiation belt electrons from a low-Earth polar orbit satellite to study mechanisms related to the spatial resolution of electron precipitation, such as electron microbursts, and those related to the measurement of energy dispersion with a high temporal resolution in the sub-auroral regions. We performed a simulation to determine the sensor design of the SST using GEometry ANd Tracking 4 (GEANT4) simulations and the Bethe formula. The simulation was performed in the range of 100 ~ 400 keV considering that the electron, which is to be detected in the space environment. The SST is based on a silicon barrier detector and consists of two telescopes mounted on a satellite to observe the electrons moving along the geomagnetic field (pitch angle 0°) and the quasi-trapped electrons (pitch angle 90°) during observations. We determined the telescope design of the SST in view of previous measurements and the geometrical factor in the cylindrical geometry of Sullivan (1971). With a high spectral resolution of 16 channels over the 100 keV ~ 400 keV energy range, together with the pitch angle information, the designed SST will answer questions regarding the occurrence of microbursts and the interaction with energetic particles. The KASISat-1 is expected to be launched in the latter half of 2020.

다채널 고속 원격 계측을 위한 광 텔레메트리

손종대,정순배,박건국,최희주,김승범,송근웅 한국항공우주학회 2007 한국항공우주학회 학술발표회 논문집 Vol.- No.-

HEPD on NEXTSat-1: A High Energy Particle Detector for Measurements of Precipitating Radiation Belt Electrons

손종대,이재진,민경욱,이준찬,이승욱,이대영,조경복,이유,나고운,강경인,신구환 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.9

Radiation belt particles of the inner magnetosphere precipitate into the atmosphere in the subauroral regions when they are pitch-angle scattered into the loss cone by wave-particle interactions. Such particle precipitations are known to be especially enhanced during space storms, though they can also occur during quiet times. The observed characteristics of precipitating electrons can be distinctively different, in their time series as well as in their spectra, depending on the waves involved. The present paper describes the High Energy Particle Detector (HEPD) on board the Next Generation Small Satellite-1 (NEXTSat-1), which will measure these radiation belt electrons from a low-Earth polar orbit satellite to study the mechanisms related to electron precipitation in the sub-auroral regions. The HEPD is based on silicon barrier detectors and consists of three telescopes that are mounted on the satellite to have angles of 0 ◦, 45 ◦, and 90 ◦, respectively with the local geomagnetic field during observations. With a high time resolution of 32 Hz and a high spectral resolution of 11 channels over the energy range from ~ 350 keV to ~ 2 MeV, together with the pitch angle information provided by the three telescopes, HEPD is capable of identifying physical processes, such as microbursts and dust-side relativistic electron precipitation (DREP) events associated with electron precipitations. NextSat-1 is scheduled for launch in early 2018.

헬리콥터 꼬리로터 시험설비를 위한 외전체 데이터 수집에 관한 연구

손종대,정순배,김태화,박건국,최희주,김승범,송근웅 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-

Cosmic Ray Enhancements in Lunar Radiation Environment Observed by CRaTER on the LRO

손종대,오수연,이유,이재진 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.74 No.6

The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument onboard the Lunar Reconnaissance Orbiter (LRO) characterizes the global lunar radiation environment and its biological impacts by measuring cosmic ray (CR) radiation. By using CRaTER data, we identify the lunar CR enhancements, which are similar to the terrestrial ground level enhancements (GLEs). GLE is a sudden and short increase in CR intensity recorded by the Earth's ground neutron monitors. We examine the origins and the characteristics of CR enhancements in the lunar space environment by using the CR intensity and dose rate according to CRaTER data. In order to determine origins of CR enhancements, we also use solar proton event (SPE) data, CR data of the Advanced Composition Explorer (ACE) equipped with a Solar Isotope Spectrometer (SIS), and proton flux data of Geostationary Operational Environmental Satellite 15 (GOES15). We identified 96 CRaTER enhancements (CREs) as increases in CR events in the lunar space environment during the period June 2009-December 2017. Unlike terrestrial GLEs, CREs are much longer and more frequent. Of the 96 CREs, 43 events are associated with SPE. The values of their physical characteristics are statistically larger than those of the CREs without associated SPEs. However, such non-SPE CREs are considered to originate from solar ejections. All CREs are associated with an increase in He flux by ACE/SIS. Even though CREs are associated with a small increase in He flux, this does indicate that some materials are ejected from the Sun; rather, it indicates that all CREs are associated with solar eruptions. Because of the very weak magnetic field and extremely rare atmosphere, the lunar space environment responds to even weak solar activity. An increase in He flux observed by ACE/SIS can be useful for monitoring the eruption of energetic particles from the Sun regardless of accompanying SPEs.

Forbush Decreases Observed by the LRO/CRaTER

손종대,오수연,이유,김어진,이주희,Sohn, Jongdae,Oh, Suyeon,Yi, Yu,Kim, Eojin,Lee, Joo-Hee,Spence, Harlan E. 한국천문학회 2012 天文學會報 Vol.37 No.2

The Lunar Reconnaissance Orbiter (LRO) launched on June 16, 2009 has six experiments including of the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) onboard. The CRaTER instrument characterizes the radiation environment to be experienced by humans during future lunar missions. The CRaTER instrument measures the effects of ionizing energy loss in matter specifically in silicon solid-state detectors due to penetrating solar energetic protons (SEP) and galactic cosmic rays (GCRs) after interactions with tissue-equivalent plastic (TEP), a synthetic analog of human tissue. The CRaTER instrument houses a compact and highly precise microdosimeter. It measures dose rates below one micro-Rad/sec in silicon in lunar radiation environment. Forbush decrease (FD) event is the sudden decrease of GCR flux. We use the data of cosmic ray and dose rates observed by the CRaTER instrument. We also use the CME list of STEREO SECCHI inner, outer coronagraph and the interplanetary CME data of the ACE/MAG instrument.We examine the origins and the characteristics of the FD-like events in lunar radiation environment. We also compare these events with the FD events on the Earth. We find that whenever the FD events are recorded at ground Neutron Monitor stations, the FD-like events also occur on the lunar environments. The flux variation amplitude of FD-like events on the Moon is approximately two times larger than that of FD events on the Earth. We compare time profiles of GCR flux with of the dose rate of FD-like events in the lunar environment. We figure out that the distinct FD-like events correspond to dose rate events in the CRaTER on lunar environment during the event period.

우주방사선폭풍탐사선 탑재체 PD (Proton Detector, 양성자 검출기)의 개념 설계

손종대,이유,오수연,민경욱,이대영,Son, Jong-Dae,Lee, Yu,O, Su-Yeon,Min, Gyeong-Uk,Lee, Dae-Yeong 한국천문학회 2012 天文學會報 Vol.37 No.2

우주방사선폭풍탐사선 (Space Radiation Storm probe: SRSP)에 탑재할 과학측정 장비들 중의 하나로 추진 중인 PD는 우주방사선 환경에서의 태양활동에 따른 고에너지 하전입자들 특히 proton의 에너지와 flux에 대한 정보를 획득하고 더불어 다른 고에너지 입자의 효과까지 포함하는 Linear Energy Transfer (LET)을 측정하기 위한 탑재체이다. 본 연구팀은 PD의 사양을 결정하기 위해서 GEANT4를 사용하여 전산모사를 수행하였으며, proton의 경우 우주 방사선 환경에서의 태양활동에 따른 고에너지 영역을 고려하여 0.1 ~ 1000 MeV 범위에서 전산 모사를 수행하였다. 본 연구팀은 특히 PD의 에너지 범위를 0 MeV ~ 5 MeV, 5 MeV ~ 10 MeV, 10 MeV ~ 20 MeV, 20 MeV ~ 35 MeV, 35 MeV ~ 52 MeV, 52 MeV ~ 72 MeV, 72 MeV 이상으로 총 7개의 channel를 결정하고 Al의 blocking material을 사용하여 검출하려는 에너지 범위를 조절한다. 또한 최적의 채널을 결정하여 silicon detector를 사용한 탑재체의 개념 설계를 실시하였다. 설계된 PD로부터 방사선대에서의 proton를 측정함으로써 태양기원 고에너지 입자에 대한 포획 및 쇠퇴에 대한 이해를 도울 것이다.

디지털센서를 이용한 추진 시스템 전자 제어장치 연구

손종대(Jongdae Son),김중회(Jung-hoe Kim),이재윤(Jae-yun Lee),김태완(Taewan Kim),윤수희(Soohee Yoon),이용환(Yonghwan Lee),곽근녕(Geunnyeong Kwak),정순배(Soonbae chung) 한국추진공학회 2010 한국추진공학회 학술대회논문집 Vol.2010 No.11

추진시스템 전자 제어장치는 추진시스템 내부의 각종 센서신호를 입력 받아 신호처리를 통해 제어알고리즘을 수행하는 장치이다. 기존의 아날로그 센서를 이용한 시스템에서는 센서와 전자제어장치의 전송에 의한 영향으로 신호감쇄가 일어나고 노이즈에 민감한 단점이 있었다. 디지털센서는 센서와 AMP, AD Converter가 하나의 모듈 안에 포함되어 있어 전송선에 의한 영향을 감소시킬 수 있으며, 전자제어장치에서 별도의 S/W 필터를 적용할 필요가 없어 제어 알고리즘의 수행시간을 단축시킬 수 있다. 본 논문에서는 디지털센서를 사용한 전자제어장치의 회로설계 및 제어알고리즘 적용에 따른 신호처리 방안에 대한 내용을 기술하였다. Electronic control units for propulsion systems are devices which compute control algorithm by processing the systems" internal sensor signals. Due to the effect of transmission between sensors and a control unit, previous analog systems have drawbacks of signal attenuation and susceptibility to noises. However, a digital sensor can be less influenced by the electrical cable line as it includes sensor, AMP, and AD converter in one module. In addition, it can reduce the process time for control algorithm because extra S/W filtering process is not needed. The current study shows how to process signals for an electronic control unit using digital sensors.

블루투스 통신을 이용한 선량계 시스템 구현

손종대(Son Jong Dae),이남호(Lee Nam Ho),김승호(Kim Seung Ho),이홍호(Lee Hung Ho) 대한전기학회 2004 대한전기학회 학술대회 논문집 Vol.2004 No.7