PRODUCT INFORMATION: Cerium Hexaboride CeBixtm For years, LaB6 has been the industry standard thermionic emission cathode material. APTech has a material, CeBixTM (Cerium Hexaboride) that can be used as a direct TM replacement for LaB6. CeBix has several advantages over LaB6 cathodes, including, longer lifetime, faster start-up, lower work function, higher brightness, lower evaporation rate and the capability to recover from Contaminates. CeBixTM cathodes are a simple, direct replacement for LaB6 cathodes in nearly every instrument currently using LaB6. TM CeBix has a significantly lower evaporation rate under certain conditions than LaB6. Studies TM have shown that the material loss rate for LaB6 is almost 75% greater than that of CeBix at 1750 K in a vacuum of 2 x 10-8 torr.Thus, CeBixTM can be expected to last 30-75% longer than a LaB6 cathode when operated under proper vacuum and temperature conditions. In some applications, carbon contamination from pumping oils, solvents, or samples can effect the surface properties of LaB6 cathodes, resulting in severely decreased electron emission. In a case of mild contamination, the operator is often unaware of the problem and only sees that it is necessary to increase the cathode heating current in order to maintain emission current. This increase in cathode temperature results in shortened lifetime. In the case of severe contamination, the emission current may be completely lost. 1600 NE Miller Street McMinnville, Oregon 97128 U.S.A. Phone: 503-434-5550 Fax: 503-434-1312 Email: [email protected] Web: a-p-tech.com Evaporation Rates for LaB6 and CeB6 TM 1000 CeBix cathodes are also effected by carbon contamination, but this contamination is removed by thermal 10) - 100 desorption at normal operating temperatures. If there is a carbon bearing gas in the system, it LaB6 10 will not adhere to the cathode Evap. Rate (g/cm2 sec 10 (g/cm2 x Rate Evap. surface at operating temperature; CeB6 therefore it will not harm the TM 1 CeBix cathode. 1700 1750 1800 1850 1900 Temperature (K) A comparison of electron characteristics of LaB6, CeBixTM, and Tungsten at typical operating temperatures. CeB6 LaB6 Tungsten Filament Brightness ( A/cm2-sr) 107 107 106 Short-term beam <1 <1 <1 current stability (%RMS) Typical service life (hr) 1,500 + 1000 100 Work funtion (eV) 2.65 2.80 4.5 Operating vacuum 10-7 10-7 10-5 (torr) Evaporation rate 2.1 x 10-9 2.9 x 10-9 NA (g/cm2-sec) Give CeBixTM a try! For more information check out our website www.a-p-tech.com.