Characterization of Amethysts from Sukamara, Central Kalimantan, Using Laser-Induced Breakdown Spectroscopy (LIBS)

- Laser-Induced Breakdown Spectroscopy (LIBS) is one method of atomic emission spectroscopy using laser ablation as an energy source. This method is used to characterize the type of amethysts that originally come from Sukamara, Central Kalimantan. The result of amethyst characterization can be used as a reference for claiming the natural wealth of the amethyst. The amethyst samples are directly taken from the amethyst mining field in the District Gem Amethyst and consist of four color variations: white, black, yellow, and purple. These samples were analyzed by LIBS, using laser energy of 120 mJ, delay time detection of 2 μs and accumulation of 3, with and without cleaning. The purpose of this study is to determine emission spectra characteristics, contained elements, and physical characteristics of each amethyst sample. The spectra show that the amethyst samples contain some elements such as Al, Ca, K, Fe, Gd, Ba, Si, Be, H, O, N, Cl and Pu with various emission intensities. The value of emission intensity corresponds to concentration of element in the sample. Hence, the characteristics of the amethysts are based on their concentration value. The element with the highest concentration in all samples is Si, which is related to the chemical formula of SiO2. The element with the lowest concentration in all samples is Ca that is found in black and yellow amethysts. The emission intensity of Fe element can distinguish between white, purple, and yellow amethyst. If Fe emission intensity is very low, it indicates yellow sample. Thus, we may conclude that LIBS is a method that can be used to characterize the amethyst samples.Key words: amethyst, impurity, laser-induced, breakdown spectroscopy, characteristic, gemstones

Review of Transverse Beam Profile Measurements Using Synchrotron Radiation

–Synchrotron radiation (SR) is a tool for non-destructive beam diagnostics since its characters are substantially related to those of the source beam. The spectrum of SR is extremely intense and extends over a broad energy range from the infrared through the visible and ultraviolet, into the soft and hard X-ray regions of the electromagnetic spectrum. The visible light (400 – 800 nm) and X-ray (0.05 – 0.3 nm) regions are used in the beam instrumentation. In the visible light region, transverse beam profile or size diagnostics can be done by an interferometer (light is observed as a wave). Meanwhile, in the submicron beam size measurements, the X-ray SR monitor is commonly used. This paper reports the review of transverse beam profile measurements using SR covering principles and practical experiences with the technique at some accelerator facilities such as Photon Factory, Diamond Light Source, CesrTA, and SuperKEKB. Key words: accelerator, beam instrumentation, transverse beam profile, synchrotron radiation, X-ray, visible light

Evaluation of shimmed DECY-13 MeV Cyclotron Magnet Using H- Beam Tracking Simulation

–Using OPERA3DTM, the magnet poles’ shimming that provide an isochronous magnetic field in DECY-13 cyclotron was designed and calculated. The shimmed magnet poles as designed were placed in the magnet and the distribution of the magnetic field in the magnet axis direction (Bz) was measured in radial ( x and y) directions using 2 probes covering x=0 to 480 mm for one probe and 481 to 960 mm for the other, and y=0 to 960 mm, all were done at z=0 in 9 hours of scanning at 5 mm steps. This paper describes the interpolation and extrapolation to obtain data for magnetic field components (Bx, By,Bz) at 1 mm resolution and at z≠0 as required for beam tracking simulations. The tracking results are used to evaluate the distribution of the shimmed magnetic fields of DECY-13. The program for the interpolation and extrapolation was written and run using a free software Scilab 5.4.1, and tested against OPERA3DTM design data. The beam can reach final energy of 13 MeV when both data was applying in the beam tracking simulation.. However when the measured data was used, the final energy of the beam reached only 3 MeV, meaning that at the place where that energy was reached the magnetic field is no longer is of isochronous and the shimming of the magnetic poles’ must be improved or redesigned to reach the final beam energy of 13 MeV.Key words: isochronous, DECY-13 cyclotron, Scilab 5.4.1, interpolation and extrapolation, beam tracking simulation

EDITORIAL

Journal of the Physical Society of Indonesia (JPSI) is an international journal published by the Physical Society of Indonesia (PSI, previously HFI or Himpunan Fisika Indonesia/Indonesian Physical Society). JPSI is the continuation of Physics Journal of the Indonesian Physical Society formally published by Himpunan Fisika Indonesia (HFI) since 1996-2001 (ISSN 1410-8860) in printed format. In HFI meeting in Denpasar on 16 October 2014 it was agreed to continue the publication of the journal in on-line format named Journal of the Indonesian Physical Society (JIPS) published in English. The name has been further changed into Journal of the Physical Society of Indonesia (JPSI) following the change of HFI (Himpunan Fisika Indonesia/Indonesian Physical Society) into Physical Society of Indonesia (PSI).Preparations for website, editors, peer reviewers, and call of papers was started in mid 2016. Papers in this first publication of JPSI (Volume 1, Number 1, April 2019) were received and accepted for publication between June 2016 and March 2019, consisting of 5 papers (minimum number of papers required for journal accreditation) in the fields of biophysics, laser materials, laser spectroscopy, and accelerator physics. However because JPSI’s ISSN was issued in July 2019, it is not applicable for April 2019 issue. Hence regrettably all issues will be published in Volume 1, Number 2, October 2019 issue.Publication of the following number of JPSI (Volume 1, Number 2) is scheduled for October 2019. We cordially invite the physics community to submit papers through our website at http://journal.fisika.or.id/jpsi. Chief Editor

Optical and Luminescence Properties of Trivalent Rare Earth Ion (Sm3+, Dy3+, and Eu3+) doped Glass for Laser Gain Medium Development : A Review

–Recently, development of laser gain medium has been more attractive to be investigated due to the laser application in human daily life. For example, laser is used for medical treatment, surgery, security system, cutting, spectroscopy characterization and sensor. Laser is produced by the system including pump source, resonator, and an optical gain medium. This paper will be focused in a gain medium based on trivalent rare earth ions (Ln3+) such as Dy3+, Sm3+, and Eu3+ doped glass. The gain medium is developed by melt and quenching technique. The raw materials are a powder that is melted at the glass transition temperature. Afterwards, the glass liquid is poured at stainless steel at room temperature and annealed for several hours. After the annealing process, the bulk glass is cut and polished for characterization. Physical, optical, and luminescence properties of the gain medium are analyzed and discussed in this paper. The CIE 1931 chromaticity diagram coordinate is calculated to define the proper coordinate of glass sample emission light. The previous research shows that Dy3+, Sm3+ and Eu3+ in glass system can emit white, orange, and reddish-orange excited by 388 nm, 403 nm and 393 nm, respectively. From the results, trivalent rare earth ion doped glass possesses high potential to be developed for laser gain medium material. Keywords: glass, laser, luminescence, optic, Ln3+

Graphene Oxide Embedded In Polymer Film As Saturable Absorber For Q-switched Erbium-doped Fiber Laser

– We demonstrate a Q-switched Erbium-doped fiber laser (EDFL) using a newly developed Graphene Oxide (GO) based saturable absorber (SA). The SA was fabricated by embedding a GO material, which was obtained through chemical oxidation of graphite into polyvinyl alcohol (PVA) film. A small piece of the film was sandwiched between two fiber ferrules via a fiber adapter and incorporated in an EDFL cavity for generating a stable Q-switching pulse train. The EDFL operates at 1560.5 nm with a pump power threshold of 16.88 mW while a pulse repetition rate was tunable from 32.45 to 81.7 kHz, and the smallest pulse-width of 5.67 μs. The Q-switching pulse shows no spectral modulation with a peak-to-pedestal ratio of 61.76 dB indicating the high stability of the laser. These results show that the GO has a great potential to be used for pulsed laser applications.Key words: graphene oxide, passive saturable absorber, Q-switching, EDFL, GO