Pressure dependence of secondary NIR scintillation in Ar and Ar/CF4

Fraga, MMR Bueno, CC Goncalves, JAC Fraga, FAF Marques, RF Policarpo, AJPL

Mmr. Fraga et al., Pressure dependence of secondary NIR scintillation in Ar and Ar/CF4, IEEE NUCL S, 48(3), 2001, pp. 330-335

17

INGLESE

Article

Apllied Physucs/Condensed Matter/Materiales Science","Nuclear Emgineering

IEEE TRANSACTIONS ON NUCLEAR SCIENCE

0018-9499 → ACNP

48

3

2001

330 - 335

ISI

0018-9499(200106)48:3<330:PDOSNS>2.0.ZU;2-6

The variation with charge gain of the total number of photons emitted per e lectron, in the visible and near-infrared (NIR) regions (400 < lambda < 100 0 mn), in Ar/CF4 mixtures, is investigated for CF4 concentrations below 15% . Measurements were performed in a uniform field configuration and results are presented for charge gains below 100, under X-ray excitation. The maxim um number of photons emitted per drifting electron (0.7 and 0.2 ph/e(-) for Ar + 2% CF4 and Ar + 10% CF4, respectively) is obtained for a charge gain G similar to 4. The spectral distribution of the emitted light in Ar/CF4 mi xtures is also analyzed. The pressure dependence (1-4 atm) of the secondary light output, in the visible and near infrared regions is studied as a fun ction of the reduced electric field E/P for pure argon and Ar/CF4 mixtures. Above the charge multiplication threshold, the maximum number of photons e mitted per electron decreases by a factor of about 1.5 when the pressure in creases from 1 to 2 atms.