What namespace do I need to use PowerShell in C# and where can I find it? System.Management.Automation?

Question

I'm trying to access PowerShell from within C# and it seems as though I need to reference the namespace System.Management.Automation and I can't find it anywhere I've searched my C: drive, google and my MSDN subscription (searching for "powershell SDK") and I can't find anything.

So my questions are:

1. Is this the namespace where I'll find the PowerShell object referenced in the codeblock below (found here)?

2. If not what namespace do I need and where can I find it?

   using (PowerShell PowerShellInst = PowerShell.Create())
   {
   
       PowerShell ps = PowerShell.Create();
   
       string param1= "my param";
       string param2= "another param";
       string scriptPath = <path to script>;
   
       ps.AddScript(File.ReadAllText(scriptPath));
   
       ps.AddArgument(param1);
       ps.AddArgument(param2);
   
       ps.Invoke();
   }
   

Answer 1

    using System.Collections.ObjectModel;
    using System.Management.Automation;
    using System.Management.Automation.Runspaces;