SQL CLR Function and .NET Framework return different results

Hello, everyone.I have rather simple CLR function:[code="vb"][SqlFunction(IsDeterministic = true, DataAccess = DataAccessKind.None)]public static SqlString GetUserName(){ return (SqlString)WindowsIdentity.GetCurrent().Name;}[/code]When I get result from .NET console app, I get correct answer "Jungle\Sektor". However, when SQL Server executes this code, it gives me "NT Service\MSSQL$SQL2014". How to get correct result? Thanks.