Use of basic principle of nucleation in determining temperature–threshold neutron energy relationship in superheated emulsions

Searching for universal behaviour in superheated droplet detector with effective recoil nuclei

“…It is observed from Table-1 that the critical energy for bubble formation is less for C 4 F 10 than that of R114. Therefore, it is expected that the incident neutron energy needed to trigger the nucleation would be less for C 4 F 10 than for R114, which is also observed in experiments [8,9,13,19], as shown in Fig.3. For lower energy neutron detection, Cf source.…”

“…In order to find out a universal energy calibration curve, the data are plotted in Fig.6, in terms of the 'threshold neutron energy' for the liquids R114, C 4 F 10 , C 4 F 8 , R142B obtained from different experiments with the 'reduced superheat' (s) [8,9,13,19,21]. Here the data for the different liquids do not follow a single line.…”

“…The energy deposition in the sensitive liquid was calculated using SRIM code [17] for the carbon, fluorine ions in C 4 F 10 and carbon, chlorine, fluorine ions in R114 for the neutron of maximum energy 6 MeV. The relation between the energy of the neutron and the operating temperature of the liquid can be obtained from the expression given below [9].…”

“…By varying the operating condition, using liquids of different boiling points and compositions, and employing different pulse analysis techniques, neutrons, α-particles, γ -rays etc, the unwanted backgrounds for cold dark matter search experiment, can be identified. Extensive studies have been made with R114 as the sensitive liquid for the response of neutrons and γ -rays of this type of detector [8][9][10]. C 4 F 10 is the most favoured sensitive liquid for cold dark matter search experiment for PICASSO (Project In CAnada to Search for Supersymmetric Objects) collaboration [11,12].…”

Threshold temperatures of heavy ion-induced nucleation in superheated emulsions

“…The calculated value of the critical LET of R114 at room temperature (about 25 1C) obtained from Eq. (3) with the reported value of 'k ¼ 0:1158' [17] is much lower than the LET of the ions at the Bragg peak and higher than the LET of the lower and flat part in the emulsions. Therefore, the emulsions may be sensitive to different heavy ions at room temperature when irradiated parallel to its long axis.…”