How to can I specify namespace to an XAttribute while having another namespace with the same value?

All I want to do is an XML document for exporting my datatable to Excel.

So what I need is something like this:

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<?mso-application Excel.Sheet?>
<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" />    

I am using System.Xml.Linq and I almost have it, but my code keeps adding "ss" to the front of Workbook. This is my code:

    XDocument xmlssDoc2 = new XDocument(new XDeclaration("1.0", "utf-8", "yes"), new 
    XProcessingInstruction("mso-application", "Excel.Sheet"));

    XNamespace aw = "urn:schemas-microsoft-com:office:spreadsheet";
    XNamespace fc = "urn:schemas-microsoft-com:office:spreadsheet";
        XElement root = new XElement(aw + "Workbook",
            new XAttribute("xmlns", "urn:schemas-microsoft-com:office:spreadsheet"),
            new XAttribute(XNamespace.Xmlns + "ss", "urn:schemas-microsoft-com:office:spreadsheet")
        );        

And the result I get is:

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<?mso-application Excel.Sheet?>
<ss:Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" />    

Any Help please!