Judul: Desain dan Karakterisasi Performa Spektrometer Small Angle Neutron Scattering (SANS) BATAN Menggunakan Program Simulasi Vitess 3.1
Abstrak: Small Angle Neutron Scattering (SANS) is a technique for mapping and providing the information of structure and dynamics in three dimension of shape, size, and orientation of an inhomogenitas in nanometer scale. The performance of SANS spectrometer can be improved through simulation or experiment. Monte Carlo method is the most appropriate method for simulating SANS experiment. One of the simulation program based on Monte Carlo method is Vitess 3.1. From the simulation, the neutron flux at the sample position decreases exponentially as a function of collimator length and decreases linearly as a function of the neutron guide length. Neutron flux distribution in the neutron beam is inhomogenous with the average value is equal to the neutron flux measurement results on the entire area of the neutron beam. The simulation result on neutron flux measurement is comparable with the experimental results.
Keyword: Small Angle Neutron Scattering (SANS), simulation, neutron flux

Judul: Analisis Distribusi Fluks Neutron dan Laju Dosis Sinar  Gamma pada Kolom Termal Reaktor Kartini untuk Boron Neutron Capture  Therapy (BNCT) menggunakan Software PHITS.
Abstrak: BNCT merupakan metode terapi kanker otak yang memanfaatkan nuklida non-radioaktif boron-10 untuk menangkap neutron termal atau neutron epitermal. Sumber neutron diperoleh dari reaktor nuklir atau akselerator partikel salah satunya reaktor Kartini. Reaktor Kartini memiliki kolom termal untuk mengurangi fluks neutron. Penelitian ini memodifikasi desain kolom termal secara komputasi menggunakan metode Monte Carlo dengan software Particle and Heavy Ion Transport Code System (PHITS) untuk memenuhi ketentuan IAEA dalam pengobatan BNCT. Material-material yang digunakan yaitu Al setebal 16 cm,perisai gamma dengan bahan Pb setebal 12 cm, filter neutron dengan bahan Ni setebal 15 cm, dan grafit pada modifikasi 1 setebal 87 cm serta pada modifikasi 2 setebal 87 cm, 74,5 cm, dan 61,5 cm. Energi yang digunakan yaitu sebesar 2 MeV, 2,5 MeV, dan 3 MeV. Hasil simulasi dari desain tersebut ditunjukkan dalam lima parameter yaitu fluks neutron epitemal, komponen neutron cepat, komponen dosis gamma, rasio antara fluks temal dan epitemal, rasio antara arus neutron dan f1uks neutron total. Modifikasi 2 dengan energi 2 MeV dan 2,5 MeV menunjukan modifikasi terbaik untuk simulasi kolom termal yang sesuai dengan ketentuan IAEA yaitu menghasilkan fluks neutron epitermal sebesar 1,78 x 10^9n/cm2s dan 1,46 x 10^9n/cm2s serta komponen dosis gamma sebesar sebesar 1,72 x 10^-13 Gycm2/n dan 1,91 x 10^-13 Gycm2/n., BNCT is a brain cancer therapy method that utilizes the non-radioactive nuclide boron-10 to capture thermal neutrons or epithermal neutrons. Neutron sources are obtained from nuclear reactors or particle accelerators, namely the Kartini reactor. The Kartini reactor has a thermal column to reduce the neutron flux. This study modifies the thermal column design computationally using the Monte Carlo method with the Particle and Heavy Ion Transport Code System (PHITS) software to meet the IAEA requirements in the treatment of BNCT. The materials used are Al 16 cm thick, gamma shield with 12 cm thick Pb material, neutron filter with 15 cm thick Ni material, and graphite in modification 1 as thick as 87 cm and in modification 2 as thick as 87 cm, 74.5 cm, and 61.5 cm. The energy used is 2 MeV, 2.5 MeV, and 3 MeV. The simulation results from the design are shown in five parameters, namely epithelial neutron flux, fast neutron component, gamma dose component, the ratio between thermal and epithelial fluxes, the ratio between the neutron current and the total neutron flux. Modification 2 with an energy of 2 MeV and 2.5 MeV shows the best modification for the thermal column simulation in accordance with the IAEA provisions, which produces an epithermal neutron flux of 1,78 x 10^9 n/cm^2s and 1,46 x 10^9 n/cm^2s and a gamma dose component of 1,72 x 10^-13 Gycm^2/n and 1.91 x 10^-13 Gycm^2/n.
Keyword: BNCT, Neutron, Gamma, Radiation Shield, Moderator, Monte Carlo, PHITS

Judul: Codiaeum Malesia
Abstrak: The Malesian genus Codiaeum has been revised based on the morphological character using available herbarium collections in Herbarium Bogor iense and loan specimens from Rijksherbarium Leiden. The study is based on the observation of 350 specimens. Eleven species have been recognized, namely Codiaeum variegatum, C. luzonicum, C. palawanense, C. trichocalyx, C. megalanthum, C. cilliatum, C. affine, C. tenerifolium dan C. hirsutum, C. macgregorii, C. ludovicianum. number of species is found in the Philippines The highest (8 species), Two species (C. tenerifolium and C. ludovicianum) endemic in Lousiade Archipelago of the New Guinea and C. affine endemic in Banguey Island. C. variegatum is widespread by nature or in cultivation almost in all of Malesian region. C. cillia tum is a species in the earliest level among the other species according to 20 selected characters.
Keyword: Codiaeum, Malesia