Nuclear photonics at ultra-high counting rates and higher multipole excitations

Journal Article · Mon Jul 09 00:00:00 EDT 2012 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4736791· OSTI ID:22069053

Thirolf, P G; Habs, D; Filipescu, D; Gernhaeuser, R; Guenther, M M; Jentschel, M; Marginean, N; Pietralla, N ^[1]; IFIN-HH, Bucharest-Magurele ^[2]

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1. Fakultaet f. Physik, Ludwig-Maximilians-Universitaet Muenchen, Garching (Germany)
2. Romania

Next-generation {gamma} beams from laser Compton-backscattering facilities like ELI-NP (Bucharest)] or MEGa-Ray (Livermore) will drastically exceed the photon flux presently available at existing facilities, reaching or even exceeding 10{sup 13}{gamma}/sec. The beam structure as presently foreseen for MEGa-Ray and ELI-NP builds upon a structure of macro-pulses ({approx}120 Hz) for the electron beam, accelerated with X-band technology at 11.5 GHz, resulting in a micro structure of 87 ps distance between the electron pulses acting as mirrors for a counterpropagating intense laser. In total each 8.3 ms a {gamma} pulse series with a duration of about 100 ns will impinge on the target, resulting in an instantaneous photon flux of about 10{sup 18}{gamma}/s, thus introducing major challenges in view of pile-up. Novel {gamma} optics will be applied to monochromatize the {gamma} beam to ultimately {Delta}E/E{approx}10{sup -6}. Thus level-selective spectroscopy of higher multipole excitations will become accessible with good contrast for the first time. Fast responding {gamma} detectors, e.g. based on advanced scintillator technology (e.g. LaBr{sub 3}(Ce)) allow for measurements with count rates as high as 10{sup 6}-10{sup 7}{gamma}/s without significant drop of performance. Data handling adapted to the beam conditions could be performed by fast digitizing electronics, able to sample data traces during the micro-pulse duration, while the subsequent macro-pulse gap of ca. 8 ms leaves ample time for data readout. A ball of LaBr{sub 3} detectors with digital readout appears to best suited for this novel type of nuclear photonics at ultra-high counting rates.

• OSTI ID: 22069053
• Journal Information: AIP Conference Proceedings, Vol. 1462, Issue 1; Conference: LEI 2011: Conference on light at extreme intensities, Szeged (Hungary), 14-18 Nov 2011; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
43 PARTICLE ACCELERATORS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BACKSCATTERING
BEAM BUNCHING
BEAM OPTICS
BEAM PRODUCTION
BEAM TRANSPORT
COMPTON EFFECT
COUNTING RATES
ELECTRON BEAMS
GAMMA DETECTION
GAMMA RADIATION
GAMMA SPECTROSCOPY
GHZ RANGE
LANTHANUM BROMIDES
LASERS
MIRRORS
PHOTON BEAMS
PHOTON-ELECTRON INTERACTIONS
PHOTONUCLEAR REACTIONS
READOUT SYSTEMS
SOLID SCINTILLATION DETECTORS