Heavy ion range anisotropy in muscovite mica Mohan Singh, Navjeet Kaur, Lakhwant Singh * Department of Physics, Guru Nanak Dev University, Amritsar, Punjab-143005, India article info Article history: Received 26 November 2009 Received in revised form 11 June 2010 Available online 1 July 2010 Keywords: Muscovite mica Layered crystal Heavy ions Stopping processes Anisotropy abstract The anisotropy of heavy ion range in layered crystal of muscovite mica has been studied in the present investigation. The freshly cleaved basal plane of the natural muscovite mica has been irradiated with various energetic heavy ions with different dip angles from UNILAC (Universal Linear Accelerator) heavy ion accelerator, GSI, Darmstadt, Germany. We have tried to investigate the causes and effects of the anisotropic nature of the layered crystalline mica on heavy ions propagation. The measured and available range values of number of heavy ions [viz: 58 Ni; 93 Nb; 129 Xe; 132 Xe; 197 Au; 208 Pb; 209 Bi; and 238 U] in muscovite mica are used to highlight the shortcomings of various range and energy loss formulations about the orientation effect on stopping processes in anisotropic media. Ó 2010 Elsevier B.V. All rights reserved. 1. Introduction Because of the great importance and interest, the field of ion matter interaction explores many unique and diverse applications in various fields of science and technology. These interests and applications require a complete experimental and theoretical study of the irradiated materials for deep understanding of the dif- ferent processes involved during the ions propagation [1–12]. The progress in accelerator technology and availability of a variety of beams of varying energy, masses and charge, availability of special type of radiation detectors, advanced instruments and develop- ment of new computational methods have led to several new demands in this field of science. In order to understand the mech- anism of ion stopping, enormous work has been done on both theoretical and experimental sides. However, despite extensive re- search over almost a century, several central problems (incomplete knowledge of stopping processes) remain unsolved. It is important to find the solution of these problems and develop new ideas in experiments and theories. The interest for the complete knowledge about the basic funda- mental processes responsible for the slowing down of energetic heavy ions in anisotropic material remains alive. Because of the complexities involved in the structures of these types of layered crystalline materials, various processes during ion penetration be- have completely different from their amorphous counterparts. The layered crystalline structure has a large effect on the range and stopping of projectiles [7]. Various theoretical and semi-empirical formulations are present to study the ion stopping processes [6,13–21], but there is no satisfactory treatment to provide a quan- titative understanding of the phenomena involved in anisotropic media. Among various radiation detecting materials, the minerals (e.g., Mica) provide unique opportunity to measure the radiation effects and defects because of the better measurement of damage [7,22– 26]. The irradiated mica can provide enormous important applica- tions in science and technology. Due to this, there is a dire need of studying various heavy ion stopping processes in it. In the present work, the anisotropic nature of layered crystal of muscovite mica has been investigated by studying the dip angle dependence of heavy ions ranges. We have tried to investigate the causes and ef- fects of the anisotropic nature of the muscovite mica on heavy ions ranges. Various famous and available range formulations [SRIM, LISE++:0-[Hub90], LISE++:1-[Zie85], LISE++:8.3.107–2-ATIMA1.2 (LS Theory) and LISE++:8.3.107–3-ATIMA1.2 (without LS correc- tion)] [17,20] have been used to check their reliability about the orientation effect on the heavy ions range calculations. 2. Muscovite mica Minerals consist of negatively charge silicate layers bonded to- gether by interlayer cations. Mica belongs to a family of minerals known as phyllosilicates. It has a monoclinic structure with unit structure consisting of one octahedral sheet sandwiching between two opposing tetrahedral sheets. It crystallizes in a layered struc- ture and can be cleaved relatively easily into thin translucent sheets. These sheets form a layer that is separated from adjacent layers by planes of non-hydrated interlayer cations. In the present investigation, natural muscovite mica (q = 2.80 gm/cm 3 ; crystallographic system: monoclinic [22,27–29]) was 0168-583X/$ - see front matter Ó 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2010.06.024 * Corresponding author. Tel.: +91 183 2450926; fax: +91 183 2258820. E-mail address: lakhwant@yahoo.com (L. Singh). Nuclear Instruments and Methods in Physics Research B 268 (2010) 2617–2625 Contents lists available at ScienceDirect Nuclear Instruments and Methods in Physics Research B journal homepage: www.elsevier.com/locate/nimb