Photoelectron–multiple-photofragment coincidence spectrometer

A new photoelectron–photofragment-coincidence spectrometer is described. Using a multiparticle time- and position-sensitive detector, this apparatus allows the study of dissociation processes of negative ions yielding three photofragments in coincidence with a photoelectron. The photoelectron spectrometer uses two detectors and works in time of flight mode, detecting 10% of the photoelectrons with an energy resolution of 5% at 1.3 eV as shown in studies of the photodetachment of O2−. A third detector is used for collection of multiple photofragments (up to 8) in coincidence. This multiparticle detector uses a crossed-delay-line anode and fast timing signals to encode the time- and position-of-arrival of multiple photofragments. The detector was demonstrated to record all three particles produced in a single three-body dissociation event, yielding an energy resolution of ≈15% ΔE/E at 0.7 eV in experiments on the three-body dissociative photodetachment of O6−.

[1]  D. Neumark,et al.  Photodissociation dynamics of the N3 radical , 1993 .

[2]  P. Kroger,et al.  Dynamics of three‐body half collisions. I. Secondary product decomposition in the photodissociation of acetyl iodide , 1977 .

[3]  K. Gericke,et al.  Photo induced three body decay , 1997 .

[4]  Z. Vager,et al.  A multiparticle 3d imaging technique to study the structure of molecular ions , 1985 .

[5]  Mark B. Williams,et al.  High resolution two dimensional readout of microchannel plates with large area delay lines , 1989 .

[6]  M. Lampton,et al.  Delay line anodes for microchannel‐plate spectrometers , 1987 .

[7]  J. Los,et al.  Time and position‐sensitive detector for dissociative processes in fast beams , 1982 .

[8]  R. Malina,et al.  Investigation of Large Format Microchannel Plate Z Configurations , 1985, IEEE Transactions on Nuclear Science.

[9]  W. J. Zande,et al.  Mode selectivity observed in the dissociations of excited normal alkanes along carbon-carbon bonds , 1991 .

[10]  Z. Amitay,et al.  A new type of multiparticle three-dimensional imaging detector with subnanosecond time resolution , 1997 .

[11]  J. Bozek,et al.  Double photoionization of spatially aligned D2 , 1998 .

[12]  R. Continetti,et al.  Complete kinematic measurement of three-body reaction dynamics: Dissociative photodetachment of O6− at 532 nm , 1998 .

[13]  D. Manolopoulos,et al.  Experimental and theoretical studies of the F+H2 transition state region via photoelectron spectroscopy of FH−2 , 1993 .

[14]  Garner,et al.  Photoelectron-Photofragment Angular Correlation and Energy Partitioning in Dissociative Photodetachment. , 1996, Physical review letters.

[15]  A. B. Jones,et al.  Towards a complete description of multiple dissociation events: A photoion–photoneutral (pi-pn3) coincidence study of Ar4+ , 1998 .

[16]  J. Huber,et al.  Three-Body Photodissociation of 1,3,5-Triazine , 1996 .

[17]  N. Djurić,et al.  Absolute detection efficiencies of microchannel plates for 0.1–2.3 keV electrons and 2.1–4.4 keV Mg+ ions , 1986 .

[18]  Xueming Yang,et al.  Photodissociation of ozone at 193 nm by high-resolution photofragment translational spectroscopy , 1995 .

[19]  P. Cosby,et al.  Photodissociation measurement of rovibrational energies and populations of molecules in fast beams , 1987 .

[20]  D. Werthimer,et al.  Microchannel Plate EUV Detectors for the Extreme Ultraviolet Explorer , 1984, IEEE Transactions on Nuclear Science.

[21]  J. Eland,et al.  Simple radial position-sensitive detector with short deadtime for time-of-flight and coincidence experiments , 1990 .

[22]  Christopher D. Martin,et al.  WEDGE-AND-STRIP ANODES FOR CENTROID-FINDING POSITION-SENSITIVE PHOTON AND PARTICLE DETECTORS. , 1981 .

[23]  J. Kohl,et al.  Fast beams apparatus for the study of photodissociation processes , 1986 .

[24]  R. Continetti.  Photoelectron± photofragment coincidence studies of dissociation dynamics , 1998 .

[25]  C. Strauss,et al.  CORRELATIONS WITHOUT COINCIDENCE MEASUREMENTS : DECIDING BETWEEN STEPWISE AND CONCERTED DISSOCIATION MECHANISMS FOR ABC A+B+C , 1990 .

[26]  David Schiminovich,et al.  Multilayer anode with crossed serpentine delay lines for high spatial resolution readout of microchannel plate detectors , 1996 .

[27]  Robert B. Walker,et al.  Three-body collision contributions to recombination and collision-induced dissociation. I. Cross sections , 1998 .

[28]  Becker,et al.  3D imaging of the collision-induced Coulomb fragmentation of water molecules. , 1995, Physical review letters.

[29]  W. C. Lineberger,et al.  Transition-State Spectroscopy of Cyclooctatetraene , 1996, Science.

[30]  C. Sherwood,et al.  TRANSLATIONAL SPECTROSCOPY STUDIES OF THE PHOTODISSOCIATION DYNAMICS OF O-4 , 1996 .

[31]  W. B. Miller,et al.  A concerted triple dissociation—the photochemistry of s‐tetrazine , 1989 .

[32]  W. C. Lineberger,et al.  A study of the singlet and triplet states of vinylidene by photoelectron spectroscopy of H2C=C−, D2C=C−, and HDC=C−. Vinylidene–acetylene isomerization , 1989 .

[33]  Daniel C. Cowles,et al.  Reinvestigation of the electron affinities of O2 and NO , 1989 .

[34]  Udo Werner,et al.  A system for correlated fragment detection in dissociation experiments , 1994 .

[35]  L. Frasinski,et al.  Covariance Mapping: A Correlation Method Applied to Multiphoton Multiple Ionization , 1989, Science.

[36]  C. Sherwood,et al.  FAST-ION-BEAM PHOTOELECTRON SPECTROMETER , 1995 .

[37]  S. North,et al.  Nonintuitive Asymmetry in the Three-Body Photodissociation of CH3COCN , 1997 .

[38]  H. Bergeron,et al.  Data treatment in multiparticle coincidence experiments: two-step dissociation processes , 1992 .

[39]  A prototype 8 × 8 pixel array X-ray detector for protein crystallography , 1997 .

[40]  J. Delmore,et al.  SIMION PC/PS2 electrostatic lens design program , 1990 .

[41]  J. Eland,et al.  Reaction dynamics of three-body dissociations in triatomic molecules from single-photon double ionization studied by a time- and position-sensitive coincidence method , 1997 .

[42]  J. G. Timothy.  Multianode Microchannel Array Detector Systems: Performance Characteristics , 1985 .

[43]  Z. Vager,et al.  A new type of multiparticle imaging detector , 1990 .