Sodium Fluoride NaF
DownloadSodium Fluoride has the lowest refractive index of all common optical materials which makes it of interest as a Cerenkov radiator in Particle Physics research. Crystran Ltd. has supplied Sodium Fluoride material which has been made into large arrays at CERN and it is used in Ring Imaging Cerenkov Counters (RICH).
| µm | No |
|---|---|
| 0.14 | 1.55 |
| 0.145 | 1.499 |
| 0.161 | 1.438 |
| 0.175 | 1.410 |
| 0.186 | 1.393 |
| 0.199 | 1.3805 |
| 0.203 | 1.3772 |
| 0.302 | 1.34232 |
| 0.405 | 1.33194 |
| 0.486 | 1.32818 |
| µm | No |
|---|---|
| 0.546 | 1.3264 |
| 0.589 | 1.32549 |
| 0.707 | 1.32372 |
| 0.811 | 1.32272 |
| 0.912 | 1.32198 |
| 1.014 | 1.3215 |
| 2.00 | 1.3170 |
| 3.1 | 1.313 |
| 4.1 | 1.308 |
| 5.1 | 1.301 |
| µm | No |
|---|---|
| 6.1 | 1.292 |
| 7.1 | 1.282 |
| 8.1 | 1.269 |
| 9.1 | 1.252 |
| 10.3 | 1.233 |
| 11.3 | 1.209 |
| 12.5 | 1.18 |
| 13.8 | 1.142 |
| 15..1 | 1.093 |
| 16.7 | 1.029 |
Sodium Fluoride is produced by vacuum Stockbarger techniques. The Sodium Fluoride is very difficult to anneal and cleaves readily limiting the useful size of pieces to about 80mm. Sodium Fluoride polishes well but must be kept in dry air to maintain the quality of the surfaces and retain the deep UV transmission needed for Cerenkov radiation from this material.
REFERENCES:
(1) H.H.Li, Absorption Coefficients, Int.J.Therm, V1, No. I, 1980