Zaheer Ali

The NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) is a 2.5m telescope in a modified Boeing 747SP aircraft that is flown at high altitude to do unique astronomy in the infrared. SOFIA is a singular integration of aircraft operations, telescope design, and science instrumentation that delivers observational opportunities outside the capability of any other facility. The science ground operations are the transition and integration point of the science, aircraft, and telescope. We… Show more

The NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) is a 2.5m telescope in a modified Boeing 747SP aircraft that is flown at high altitude to do unique astronomy in the infrared. SOFIA is a singular integration of aircraft operations, telescope design, and science instrumentation that delivers observational opportunities outside the capability of any other facility. The science ground operations are the transition and integration point of the science, aircraft, and telescope. We present the ground operations themselves and the tools used to prepare for mission success. Specifically, we will discuss operations from science instrument delivery to aircraft operation and mission readiness. We will also provide a discussion of instrument life cycle including maintenance and repair, both before and after acceptance by the observatory as well as retirement. Included in that will be a description of the facilities and their development, an overview of the SOFIA telescope assembly simulator, our deployment capabilities, as well as an outlook to the future of novel science instrument support for SOFIA. Show less

The x-ray spectrum between 18 and 88 keV generated by a petawatt laser driven x-ray backlighter target was measured using a 12-channel differential filter pair spectrometer. The spectrometer consists of a series of filter pairs on a Ta mask coupled with an x-ray sensitive image plate. A calibration of Fuji™ MS and SR image plates was conducted using a tungsten anode x-ray source and the resulting calibration applied to the design of the Ross pair spectrometer. Additionally, the fade rate and… Show more

The x-ray spectrum between 18 and 88 keV generated by a petawatt laser driven x-ray backlighter target was measured using a 12-channel differential filter pair spectrometer. The spectrometer consists of a series of filter pairs on a Ta mask coupled with an x-ray sensitive image plate. A calibration of Fuji™ MS and SR image plates was conducted using a tungsten anode x-ray source and the resulting calibration applied to the design of the Ross pair spectrometer. Additionally, the fade rate and resolution of the image plate system were measured for quantitative radiographic applications. The conversion efficiency of laser energy into silver Kα x rays from a petawatt laser target was measured using the differential filter pair spectrometer and compared to measurements using a single photon counting charge coupled device. Show less

The gamma reaction history (GRH) diagnostic is a multichannel, time-resolved, energy-thresholded γ-ray spectrometer that provides a high-bandwidth, direct-measurement of fusion reaction history in inertial confinement fusion implosion experiments. 16.75 MeV deuterium+tritium (DT) fusion γ-rays, with a branching ratio of the order of 10−5γ/(14 MeV n), are detected to determine fundamental burn parameters, such as nuclear bang time and burn width, critical to achieving ignition at the National… Show more

The gamma reaction history (GRH) diagnostic is a multichannel, time-resolved, energy-thresholded γ-ray spectrometer that provides a high-bandwidth, direct-measurement of fusion reaction history in inertial confinement fusion implosion experiments. 16.75 MeV deuterium+tritium (DT) fusion γ-rays, with a branching ratio of the order of 10−5γ/(14 MeV n), are detected to determine fundamental burn parameters, such as nuclear bang time and burn width, critical to achieving ignition at the National Ignition Facility. During the tritium/hydrogen/deuterium ignition tuning campaign, an additional γ-ray line at 19.8 MeV, produced by hydrogen+tritium fusion with a branching ratio of unity, will increase the available γ-ray signal and may allow measurement of reacting fuel composition or ion temperature. Ablator areal density measurements with the GRH are also made possible by detection of 4.43 MeV γ-rays produced by inelastic scatter of DT fusion neutrons on C12 nuclei in the ablating plastic capsule material. Show less

The National Ignition Facility (NIF) neutron time of flight (NTOF) diagnostic will measure neutron yield and ion temperature in all NIF campaigns in DD, DT, and THD∗ implosions. The NIF NTOF diagnostic is designed to measure neutron yield from 1×109 to 2×1019. The NTOF consists of several detectors of varying sensitivity located on the NIF at about 5 and 20m from the target. Production, testing, and calibration of the NIF NTOF detectors have begun at the Laboratory for Laser Energetics (LLE)… Show more

The National Ignition Facility (NIF) neutron time of flight (NTOF) diagnostic will measure neutron yield and ion temperature in all NIF campaigns in DD, DT, and THD∗ implosions. The NIF NTOF diagnostic is designed to measure neutron yield from 1×109 to 2×1019. The NTOF consists of several detectors of varying sensitivity located on the NIF at about 5 and 20m from the target. Production, testing, and calibration of the NIF NTOF detectors have begun at the Laboratory for Laser Energetics (LLE). Operational tests of the NTOF detectors were performed on several facilities including the OMEGA laser at LLE and the Titan laser at Lawrence Livermore National Laboratory. Neutron calibrations were carried out on the OMEGA laser. Results of the NTOF detector tests and calibration will be presented. Show less

We are developing cryogenic high-resolution X-ray, Gamma-ray and neutron spectrometers based on superconducting Mo/Cu transition edge sensors. Here we discuss the sensor design for different applications, present the photolithographic fabrication techniques, and outline future detector development to increase the spectrometer sensitivity.