Charge and mass resolved time of flight observations of 140 fs laser produced ions
- Lawrence Livermore National Laboratory, P.O. 808, Livermore, California 94550 (United States)
Ions from this plasma are self-extracting with energies of 0.1 to 100 keV, the extraction potential being one of the desired observables. The charge/mass ([ital z]/[mu], [mu] is mass in AMU) separation is provided by a static magnetic field ([ital B][center dot][ital L]=1280 G cm, FWHM=14 mm) located 5 cm from the linear (1[minus][ital d]) detector. Displacement along the detector axis is thus proportional to [ital z]/[mu](1/[ital v]). The detector is a gold cathode MCP with a fast (sub-ns) phosphor. The phosphor output is coupled into a streak camera (typical sweep 8.5 or 24 [mu]s total) through a coherent fiber bundle. Streak images are grabbed with a 14-bit CCD. The signature of any specific ion is a straight line of slope proportional to [ital z]/[mu]. Since there are usually more than one charge state of a given ion, integer multiple slopes appear. Thus [ital z] [ital and] [ital m] can be found. Absolute calibration is taken from the slope of the proton streak, which is always present with our plasmas. While providing the same information as a Thomson parabola, the straight line images are easier to extract information from and offer resolution with less energy dependence. By providing mass and time of flight information, the product of [ital z][center dot][ital T][sub [ital e]] can be determined unambiguously during the hydrodynamic acceleration of the plasma.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6711883
- Journal Information:
- Review of Scientific Instruments; (United States), Vol. 66:1; ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
Similar Records
High spectral resolution, photon counting detector for Doppler temperature measurements in magnetically confined plasmas
A photon-counting, subnanosecond, imaging camera for x-ray detection