J. Nucl. Phy. Mat. Sci. Rad. A.

Jung's Theorem Applied in Nuclear Track Methodology

G. Chacin, L. Sajo-Bohus, J.J. Rojas Hancco and G. Espinosa

KEYWORDS

Nuclear track density, cr-39 detectors, beam diagnostics, charged particle sources

PUBLISHED DATE August 6, 2018
PUBLISHER The Author(s) 2018. This article is published with open access at www.chitkara.edu.in/publications.
ABSTRACT

Nuclear track density provides accelerator beam imaging and diagnostic employing CR-39 passive detectors. Counting charged particles related tracks by automated reading systems depend on the accuracy of microscope field view other that chemical etching procedure and frequency of overlapped tracks. The study, to propose a method to determined track density for analyser optical field view not calibrated. The approach Jungs’ theorem, provides the area value based on the maximum distance for two selected etched tracks. Results show that the new method has its importance when microscope field view calibration is not available with precision for accelerator beam diagnostics.

INTRODUCTION

In accelerator beam monitoring employed diagnostic technique by both destructive and non-destructive procedure to determine beam intensity, its longitudinal, transverse shape and size including emittance, perturbative or slightly disturbing and destructive method are employed such as scintillator screen for beam intensity study, to determine beam transverse size, shape and position respect the centre line. An alternative plastic detector is particularly useful for low-beam-current (picoAmp) profile monitoring and are successfully employed in accelerator design development. Passive track detector such as C12H18O7 polymer etched in 6N KOH solution at 60°C for 18h provide images on charged particle as geometrical cones visible under light transmission microscope. The number of tracks per detector area provide trough density (tracks/unit area) information for instance on the accelerator beam imaging and diagnostics; the information on beam intensity is derived from the number of particles observed per unit area and the beam tails parameter from track density gradient [1]. It is then essential to have precise value for microscope field value to determine track density or number of tracks per unit area. Polyallyldiglicol carbonate (PADC) currently under the trade mark CR-39TM play an important role in determining beam parameter for radioisotope production, personal dosimetry [2] and cancer treatment [3] among other fields. Since track density provide information on dose transference efficiency i.e. how uniform is both the beam and its spatial dispersion (beam broadening and anisotropy) inside a give volume.
To establish a technique to determine with less uncertainty track density, the Joung theorem is applied to determine the best area in that etched nuclear tracks density shall be determined. The process for track visualization employ a thermoset polymer, PADC detector of 1 mm thick (density: 1.30 g cm–3, called LantrackTM, produced by Landauer Inc). The chemical etching process is standardized using a thermostatic water bath in which a 500ml beaker with 6N KOH solution in a thermoregulated water bath at 60±0.1°C Then they were washed with distilled water and dried with absorbent paper, avoiding any mechanical damage to the detectors surface, following a very well establish protocol. Later, the detectors were analyzed with an automatic Digital Image Analysis System (DIAS); detailed description is given by Gammage and Espinosa [4]. Etched tracks are analyzed and displayed by Microsoft ExcelTM software on a personal computer for further data handling.

Page(s) 51-55
URL http://dspace.chitkara.edu.in/jspui/bitstream/123456789/738/1/08_JNP.pdf
ISSN Print : 2321-8649, Online : 2321-9289
DOI 10.15415/jnp.2018.61008
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