ENHANCED-BRIGHTNESS, SHORT-PULSE X-RAYS LASERS

We are developing short-pulsed, enhanced-brightness, and coherent x-ray lasers (XRLs) for applications in areas such as plasma imaging. In a traveling wave pump setup the optical laser creating the XRL plasma sweeps along the lasant axis at the same speed as the x-rays. This technique becomes increasingly important as the target length increases and the gain duration shortens. An order of magnitude increase in output energy has been measured usinf the traveling wave pump. Using multiple pulse techniques and multilayer miners to inject the output. of one pulse back into the plasma formed by a later pulse we have begun to develop the x-ray analog of a multi-pass amplifier. The use of multiple pulses separated by as much as 1.6 ns reduces multilayer mirror damage. This injection technique is demonstrated by imaging the near-field emission profiles of the XRL. The addition of multilayer beamsplitter will allow us to effectively produce a soft XRL cavity.