ADRON instrument for future missions to Moon and Mars: active neutron and gamma-ray spectroscopy

<p>The series of ADRON instruments are developed in Russian Space Research Institute (IKI) for Russian Luna-25, Luna-27 and Roscosmos-ESA ExoMars-2022 landers. The main goal of this experiment is studying of elemental composition of planetary sub-surface down to 1 m. Using pulsing neutron generator and observing albedo after-pulse neutron and gamma-ray emission from the soil, one can detect layering stratification of hydrogen and mass fractions of other elements.</p><p>Both instruments consist of two blocks: pulsing neutron generator (PNG) with 14 MeV neutron pulse duration around 1 microsecond, and detector block with neutrons and gamma-ray detectors based on <sup>3</sup>He counters and CeBr<sub>3</sub> (LaBr3) scintillator, respectively. <sup>3</sup>He counters allow to detect thermal and epithermal neutrons, which are the most sensitive to hydrogen in underlying soil, and gamma-ray detector allows to detect nuclear lines at the energy range from 200 keV up to 10 MeV. Readout and digital electronics is designed to minimize the dead-time of signal processing. It allows to accumulate the after-pulse profiles of emission of neutrons and gamma-rays with very good time (from 2 microsecond) and spectral resolutions (about 4 % for 662 keV).</p><p>The results of laboratory measurements and numerical simulations for ADRON units will be presented for post-pulse emission of neutrons and gamma rays from the planetary soil with different water content, elementary composition and layering structure.</p><p> </p>

APLIKASI ALAT PULSE NEUTRON LOGGING UNTUK MENENTUKAN ZONA HIDROKARBON BARU DI LAPANGAN X

Pengukuran Neutron Porosity pada sumur terbuka (Open Hole) ditujukan untuk mengukur indeks hidrogen yang terdapat pada formasi batuan. Indeks hidrogen didefinsikan sebagai rasio dari konsentrasi atom hidrogen setiap cm3 batuan terhadap kandungan air murni pada suhu 75oF. Neutron Porosity log tidaklah mengukur porositas sesungguhnya dari batuan, melainkan yang diukur adalah kandungan hidrogen yang terdapat pada pori-pori batuan. Secara sederhana, semakin berpori batuan semakin banyak kandungan hidrogen dan semakin tinggi indeks hidrogen. Sehingga, shale yang banyak mengandung hidrogen dapat ditafsirkan memiliki porositas yang tinggi pula. Untuk mengantisipasi uncertainty tersebut, maka pada praktiknya, interpretasi porositas dapat dilakukan dengan mengelaborasikan log density logging. Pengukuran diatas dilakukan pada sumur terbuka (Open Hole) untuk mengetahui respon dari litology, salinity, tipe fluida dan lain-lain. Sedangkan, pengukuran Neutron pada sumur tertutup (Cased Hole) akan sulit dan membutuhkan alat yang khusus. Pada Tesis kali ini penulis ingin memberikan suatu metode penilian formasi dengan mengunakan alat Reservoir Tool Monitoring (RMT) yang dapat bekerja di dalam casing maupun di dalam tubing. Kata Kunci : Alat Pulse Neutron Logging, Hidrocarbon dalam Tubing

Investigation of martian soil properties by complementary instruments ADRON-EM and RM instruments of ExoMars 2022 mission

<p>The ExoMars landing mission, which is currently scheduled to launch in 2022, will carry the active gamma ray and neutron spectrometer ADRON-EM and compact passive neutron spectrometer ADRON-RM to the equatorial region of Mars as part of the mission's science payload. The main science objective of the ExoMars mission is dedicated to understanding the evolution and habitability of Mars.</p> <p>ADRON-EM instrument is developed in Space Research Institute (IKI) for active neutron sensing of the soil from the stationary landing platform. The main goal of this experiment is study of elemental composition of the martian subsurface down to 1 m. The instrument consists of two units, the block of detectors and electronics (DE) and the pulse neutron generator (PNG). Measuring post-pulse neutron and gamma ray emission from the soil, one can detect layering stratification of hydrogen and other major elements of the soil.</p> <p>The second complementary instrument ADRON-RM (IKI) is installed on the Rover. It will measure the spatial variability of neutron flux emitted from the martian surface along the traverse. The data processing will convert the raw data into an estimation of bulk water distribution and abundance of neutron absorbing elements, mainly chlorine and iron. The instrument will also provide continuous monitoring of the neutron component of the radiation background on the surface which is necessary to know for planning future human missions to the planet.</p> <p>In the beginning of the surface mission after landing, there is the unique possibility to perform the measurement of subsurface density by both instruments operating together. The data for this analysis will be obtained from different distances between rover and landing platform.</p> <p>Description of ADRON-EM and RM instruments and expected results will be presented.</p>