An arc discharge lamp has an arc chamber with an amalgam tip attached to and communicating with the arc chamber through a constricted area. Further, the invention provides a specific interferon alpha sequential regimen for treating cancers, especially those showing resistance to classical anti-proliferative chemotherapy drugs such as stem cell driven cancers. The nozzle part is sealingly inserted into an opening in the cylinder head and a cross brace is fixed to the cylinder head in a deflection-resistant manner, overlapping with at least one injector device.