Tetraethyl ammonium hydroxide (TEAH) as etchant of CR-39 for the determination of fluence of alpha particles

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Vol. 325; pp. 47 - 53
• Main Authors: Joshirao, Pranav M., Vyas, Chirag K., Eappen, K.P., Shin, Jae Won, Hong, Seung-Woo, Manchanda, Vijay K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-04-2014
• Subjects: Activation energy; Alpha particles; CR-39; Tetraethyl ammonium hydroxide; Track etching efficiency; Tetraethyl ammonium hydroxide; CR-39; Activation energy; Track etching efficiency; Alpha particles
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2014.02.001

•Etching time of CR-39 with TEAH–NaOH mixture (at 80°C) is less than 20min.•Etched products enhance etching rate.•VB and VT values increase exponentially with temperature.•Activation energy of bulk etching and track etching were determined as 0.87±0.02eV.
Choice of chemical etchant and temperature are pivotal to the successful employment of organic/polymeric solid state nuclear track detectors for determining the fluence of charged particles like protons, alpha and other heavy ions. Poly(diethyleneglycol-bis-(allylcarbonate)) (CR-39) is one of the most sensitive detectors for monitoring the alpha particles but suffers from the drawback of long etching period. An attempt has been made in the present work to investigate a mixture, 20% (v/v) tetraethylammonium hydroxide (40%) – 80% NaOH (6M) (TEAH–NaOH) at varying temperature as an alternate etchant. It was found that bulk/track etch rate increased and as a consequence etching time decreased significantly (about 10 times) when the mixture was used at 80°C. Mechanistically, improved efficiency of TEAH–NaOH was attributed to its larger organophilicity and lower etching activation energy as compared to NaOH.