Double Spectrometer Research Articles

The Raman and infrared spectra and normal coordinate analysis for 1,2‐diiodotetrafluorobenzene

AbstractThe Raman spectrum of 1,2‐diiodotetrafluorobenzene was recorded in the region 50–2000 cm−1 on a Jarrell‐Ash Model 25–300 double monochromator spectrometer using 5145 Å radiation from an argon‐ion laser. The depolarization ratios of the Raman lines were measured in CS2 and CHCl3 solutions. The infrared spectrum was recorded in CS2 and CHCl3 solutions in the region 180–200 cm−1 on a Perkin‐Elmer 180 spectrometer using a CsI cell. The fundamental vibrations were assigned on the basis of the frequencies and relative intensities of the bands observed in the Raman and infrared spectra and the depolarization ratios of the Raman lines. A normal coordinate analysis was also performed to check the vibrational assignments.

The piotron at SIN-a large superconducting double torus spectrometer

A test facility for radiation therapy with negative /pi/-mesons was constructed in Switzerland. The facility is a large double torus spectrometer similar to the Stanford design. For variation of stopping depth different momenta are selected by variation of the magnetic field. Superconducting ac magnets are necessary for tumor scanning and represent a major part of such a facility. Main design features and performance are reported. 10 refs.

A double quadrupole for mass spectrometry/mass spectrometry

A double quadrupole mass spectrometer has been constructed to study unimolecular and collision-induced dissociation products from mass-selected ions. The two quadrupoles are closely coupled and the dissociation products sampled from a 2.5-mm interquadrupole region. Spectra obtained on the double quadrupole instrument are compared with published data obtained with triple quadrupole and reversed-sector (MIKE) mass spectrometers. The results indicate that the simple double quadrupole spectrometer is a highly efficient device which is a viable alternative to more complex quadrupole or sector instruments for obtaining dissociation spectra of mass-selected ions.

The behaviour of electrostatic double probes in plasmas with high-amplitude RF fields

In experiments, concerned with the RF heating of plasma, the very large high frequency fields (1 kV cm-1, 1 MHz in these experiments) cause characteristic distortions of the signals of electrostatic double probes and particle spectrometers: The probe current appears as a series of narrow spikes, while the electric fields inside the plasma change sinusoidally with time. A model is presented explaining the experimental observations and allowing the evaluation of the signals with respect to Te and ne.

Double axis, two-crystal x-ray spectrometer

A two-crystal double axis x-ray spectrometer, capable of goniometric accuracy on the order of 0.1", has been developed. Some of its unique design features are presented. These include (1) a modified commercial thrust bearing which furnishes a precise, full circle theta:2theta coupling, (2) a new tangent drive system design in which a considerable reduction of the lead screw effective pitch is achieved, and (3) an automatic step scanning control which eliminates most of the mechanical deficiencies of the tangent drive by directly reading the tangent arm displacement.

Formula omitted] radiative decays into ππγ and KKγ

The radiative decays of J ψ into f/γ, f′γ, ππγ and KKγ have been measured using the double arm spectrometer DASP at DORIS. We find B(J/ φ→ fγ)=(J/ φ→ fγ)/(J/ φ→all)=(0.9±0.3)×10 −3 to (1.5±0.4)×10 −3 depending on the multi- pole mode of the J ψ decay and that B( J/φ→ f′γ) B( J/γ→ fγ)⪕ 1 3 .

Quergleiten einzelner aufgespaltener versetzungen in germanium

Abstract Cross slip of single extended dislocations in germanium Isolated dislocation loops with a screw segment intersecting a (111) or a (541) surface have been introduced in dislocation-free germanium single crystals. The behaviour of the loops during annealing in the temperature range of 673-823 K and at low stresses of 0-4 N/mm2 were investigated both by the double-etch-pit method, and by X-ray topography with a double X-ray spectrometer. Two competing processes were observed : the shrinkage of the loops and the cross slip of the screw segments intersecting the surface. The velocity of shrinkage and the frequency of the cross slip were measured and the activation energies of both processes determined. The activation energy of cross slip is compared with theoretical calculations. Zusammenfass In versetzungsfreien Germaniumeinkristallen werden isolierte Versetzungsringe eingeführt, bei denen jeweils ein Schraubensegment eine (111) oder eine (541)-Oberfläche durchstösst. Das Verhalten dieser Ringe während einer Glühbehandlung im Temperaturbereich von 673-823 K und bei kleinen Spannungen 0-4 N/mm2 wird sowohl mit der Doppelätzmethode wie röntgentopographisch mit einem Doppel-kristallspektrometer untersucht. Zwei konkurrierende Prozesse werden dabei beobachtet: das Zusammenziehen der Versetzungsringe und ein Quergleiten der die Oberfläche durchstossenden Schraubensegmente. Die Geschwindigkeit des Schrumpfens und die Häufigkeit der Quergleitprozesse werden in Abhängigkeit von Temperatur und Spannung gemessen und die Aktivierungsenergien bestimmt. Die Aktivierungsenergie für das Quergleiten wird mit theoretischen Berechnungen verglichen.

The three photon final state produced in e +e − collision at 3.6 GeV and at the ψ′

The three photon final state produced in e +e − collisions at 3.6 GeV and at the mass of the ψ′ resonance has been measured using the nonmagnetic part of the double arm spectrometer DASP. A total of 31 events is observed outside the resonance region compared to 35.1 events predicted from QED. At the mass of the ψ′ 49 events are observed compared to 37.2 events expected from QED. Limits on radiative decays via intermediate states are given.

Radiative decays of the [formula omitted] and evidence for a new heavy resonance

The three photon final state produced in e +e − collisions has been measured at the mass of the J ψ resonance using the nonmagnetic part of the double arm spectrometer DASP. The decays J ψ → ηγ, η'γ and π o γ were observed and their branching ratios are given. A four standard deviation signal was observed in the γγ mass spectrum at a mass of (2.83 ± 0.03) GeV. An upper limit is given for the direct decay J ψ → 3γ .

Resonance Raman Scattering with Tunable Lasers

Abstract Raman scattering has had a long and very fruitful development since the announcements in 1928 by Sir C. V. Raman [1] of theobservation of this inelastic light scattering in several liquids and by L. Mandelstam 121 of similar scattering in crystalline quartz. Most of the early work was performed with high intensity mercury lamps using especially the lines at 4358, 4046, and 2536 A. The development of the continuous wave helium-neon laser in 1962 and the more power- ful argon-ion laser shortly thereafter quickly led to a renewed vigor in the field. With Porto's work in 1964 using the He[sbnd]Ne laser [3] and his contributions toward refinements of the double spectrometer [4], many workers began renewed studies of a great variety of materials - solids, liquids, and gases. These studies have extended the classification of the frequencies and symmetries of the normal modes of vibrations in molecules and crystals and of rotational and vibrational lines in molecular gases.

Evidence for weakly decaying new hadrons in e +e − collisions above 4 GeV cms

Single electrons produced with hadrons in e +e − collisions at cms energies of 4.0 to 4.2 GeV have been observed at DORIS using the double arm spectrometer DASP. The measured electron spectrum peaks at low momentum and the associated hadron multiplicity is high. These experimental results are consistent with the electromagnetic production and weak decay of a hadron with a new quantum number that is conserved by the strong and electromagnetic interaction. The electron yield at 3.7 GeV (the ψ′ resonance) and at lower energies was found to be consistent with the estimated background, indicating that the production threshold lies between 3.7 and 4.0 GeV.

A large area time-of-flight system with a resolution of 0.5 ns fwhm

We have built a time-of-flight counter hodoscope consisting of 62 scintillation counters with dimension 172×20×2 cm 3 each. The counters were tested using electrons from an external beam at the DESY synchrotron in Hamburg. The time of flight was measured between a small scintillation counter and the hodoscope counters. We obtained a resolution of 0.5 ns fwhm, summed over all 62 counters. At present the system is in operation at the Double Arm Spectrometer DASP at the storage ring DORIS. By using data on the reactionse +esu−→e +e −, μ + μ − we have obtained a resolution of 0.6 ns fwhm, which will be improved in the near future.

A double magnetic spectrometer for the study of hypernuclei production by K − in flight

The experimental set-up used to study the production of hyper-nuclei by the ( K −, π −) reaction induced by K − of 390 MeV/ c with forward emitted π − is described. The momenta of the incident K − and of the emitted π − were measured by a very compact double magnetic spectrometer, non-focusing, with wide aperture. A single magnet with the target in the middle was used for this purpose. Six pairs of multiwire proportional counters (1700 activated wires) placed in front of, inside and after the magnet were used to measure the trajectories of the particles. Particular care was devoted to the trigger of the experiment and mainly to the separation of K − from π − with thin scintillators and threshold Cherenkov counters. A PDP-11/20 on-line computer controlled the experiment. A total energy resolution of 6 MeV (fwhm) on the excitation spectrum of the hypernucleus was obtained. The solid angle for detection of outgoing particles around 0° was of the order of 8×10 −2 sr.

The design and operation of the Yale-NAL-BNL hyperon beam

The design and operation of a negative hyperon beam is described. Fluxes of 200 Σ − and 2 Ξ − per 1.5 × 10 11 interacting protons are delivered to a double magnetic spectrometer where decay products are analyzed. Hyperons are identified by kinematic fitting of their decays.

Optimum Slit Settings for Double Spectrometers at High Grating Angles

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text David A. Stephenson, "Optimum Slit Settings for Double Spectrometers at High Grating Angles," Appl. Opt. 11, 2378-2379 (1972) Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

Forward Magnetic Scattering Amplitude of Iron for Thermal Neutrons

The forward magnetic scattering amplitude of iron for thermal neutrons was determined on an absolute scale in two different experiments: the refractive bending of a polarized neutron beam by a small-angle prism (apex angle 32\ifmmode^\circ\else\textdegree\fi{}) and the refractive bending of an unpolarized neutron beam by a large-angle biprism (apex angle 150\ifmmode^\circ\else\textdegree\fi{}) of polycrystalline iron magnetized to saturation. This magnetic scattering amplitude, determined at 301 \ifmmode^\circ\else\textdegree\fi{}K, was established as being 0.589(6) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}12}$ cm/atom and is in excellent agreement with the value of 0.587 (1) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}12}$ cm/atom that is calculated from magnetization measurements. The measurement confirms the discrepancy between this value and that extrapolated by a $3d$-electron form factor from earlier Bragg reflection measurements, namely 0.645 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}12}$ cm/atom, and this supports the presence of an anomalous magnetic form factor in iron at scattering angles smaller than permitted in Bragg reflection. Simultaneous measurement of the nuclear scattering amplitude yielded 0.954(6) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}12}$ cm/atom in good agreement with previous powder measurements. The small refractive bending angles over a range of 20 sec of arc were measured by placing the prisms between the crystals of a double perfect-crystal spectrometer with torsion goniometer control.

Attempts to Observe the Absolute Intensity and the Centre-to-Limb Variations of the Sun in the Vacuum Ultraviolet Region

Calibration for two rocket-borne spectrometers to observe the absolute intensity and the centre-to-limb variations of the Sun between 1500 Å and 2000 Å is described. The procedure of the calibration is divided into two parts, (a) the measurements of the transmission of the spectrometers, and (b) the absolute detector calibration.The double dispersive spectrometer has been planned to be launched in September 1970, but it was postponed until the coming winter, and the single dispersive spectrometer will be launched in January 1971.

Lifetimes of some excited states in 182W

Abstract The lifetimes of five excited states in 182W have been measured using a magnetic double lens spectrometer coupled to a pulse-height converter and a fast-slow coincidence system. The half-lives of the 100 keV, 1289 keV, 1374 keV, 1488 keV and the 1553 keV levels were found to be 1.48 ± 0.03 ns, 1.06 ± 0.02 ns, 1.70 ± 0.05 ns, ≦ 1.70 ns and 1.35 ± 0.04 ns, respectively. Some nuclear parameters are deduced and discussed.

Triple correlations in the 58Ni(p, γγ) 59Cu and 62Ni(p, γγ) 63Cu reactions

Approximately 50 resonances having a yield of greater than 100 gamma rays per μC were discernible from the 62Ni(p, γ) 63Cu reaction in the range of proton energy from 1100 keV to 1850 keV. Gamma-ray energy measurements obtained by utilizing scintillation and lithium-drifted silicon spectrometers yield 3.42±0.02 MeV and 6.14±0.02 MeV for the Q-value of the 58Ni(p, γ) 59Cu and 62Ni(p, γ) 63Cu reactions, respectively. The existence of intermediate states was observed in 59Cu at 0.49±0.01, 0.91±0.01, 1.38±0.02, 2.00±0.02 and 2.32±0.02 MeV; and in 63Cu at 0.67±0.01 and 1.55±0.02 MeV. Triple-correlation measurements were performed with a double sum-coincidence spectrometer at resonance energies of 1424, 1663 and 1715 keV for the 58Ni(p, γγ) 59Cu reaction and at resonance energies of 1374, 1414, 1507 and 1634 keV for the 62Ni(p, γγ) 63Cu reaction. These measurements permitted J π assignments of ( 1 2 ), 5 2 −, 5 2 −, 5 2 − and ( 3 2 −) or ( 5 2 −) to the intermediate states in 59Cu at 0.49, 0.91, 1.38, 2.00 and 2.32 MeV, respectively; and ( 1 2 ) and either ( 3 2 −) 5 2 −), or ( 3 2 +) to the intermediate states in 63Cu at 0.67 and 1.55 MeV, respectively. The E2/M1 amplitude ratios were obtained whenever possible from the correlation data.

Application de la théorie dynamique de la diffraction X à l'étude de la diffusion du bore et du phosphore dans les cristaux de silicium

The dynamical theory of X-ray scattering of distorted crystals is applied to the case of silicon crystals in which boron has been diffused. Double spectrometer reflexion profiles can thus be theoretically computed. Agreement with the experimental profiles is good except that computed junction depths are higher than the values measured by metallographic methods. On the other hand, the present method leads to a reliable determination of the diffusion coefficient of boron in the case of relatively high concentrations.