Detector slit

The interfacing of the CAT with the MS-9 is illustrated in Figure 5. The ions in the m/e region of interest, after being focussed, pass by a small magnet coil which deflects the beam back and forth over the detector slit. After passing through the slit, the ions strike an electron... 

The Compton profile measurements on Cu and Cu 953AI0047 were performed at ID 15b of the ESRF. Figure 1 shows the setup of the scanning-type Compton spectrometer used. It consists of a Si (311) monochromator (M), a Ge (440) analyzer (A) and a Nal detector (D). The signal of an additional Ge solid state detector (SSD) was used for normalization. ES, CS and DS denote the entrance slit, the collimator slit and the detector slit, respectively. For each sample 10 different directions were measured with approximately 1.5-2 x 103 7 total counts per direction. The incident energy was 57.68 keV for the Cu and 55.95 keV for the Cuo.953Alo.047 measurement. 

J (s) = Jl (s) dsi is the slit-smeared scattering intensity, P(t is the total primary beam intensity per slit-length element - a quantity determined by the moving slit device. R is the distance between sample and detector slit as measured on the optical axis of the camera. L is the (fixed and known) length of the detector slit in the registration plane. H is the (adjustable) height of the detector slit. exp(—jut) is the linear absorption factor of the sample19. 

It is thus reasonable to make the slit height H of the detector slit wider than the integral breadth of the intrinsic primary beam profile. In this case the observed integral breadth equals H - and can be accurately determined from the measured primary beam profile. 

Example The influence of relative slit width on peak shape and resolution is demonstrated on the second isotopic peak of toluene molecular ion, m/z 94 (Fig. 4.25). With the entrance slit at 50 pm and the exit slit at 500 pm the peak is flat-topped (left), because a narrow beam from the entrance sweeps over the wide open detector slit keeping the intensity constant as the scan proceeds until the beam passes over the other edge of the slit. Closing the exit slit to 100 pm increases resolution to 2000 without affecting the peak height (middle), but reduces the peak area by a factor of 4 in accordance with an increase in resolution by the same factor. Further reduction of the exit slit width to 30 pm improves... 

Spherical aberration at the detector slit is minimized by further grinding the cry stal surface to fit the radius of the Rowland circle. With the resultant... 

X-Ray diffraction data of atenolol are presented in Table 7 (5) The diffraction spectrum was produced by monochromatic radiation from the CuK line (1.542 a) which was obtained by excitation at 55 kV and 2o mA. Recording conditions were as follows. Optics detector slit o.2° M.R. soller slit, 5° beam slit, o.ooo7 Ni filter, 3° take off angle. Goniometer scan at 2°, 2o/min. Detector amplifier gain 16 coarse, 9 1 fine. Scintillation co-... 

I, must be deconvoluted from the laser line shapes the Raman resonance line shapes the detector slit function and the polarization properties of the laser and signal fields. 

In this beam-sweeping scheme the effective spatial distribution of the ions sampled is defined by the characteristics of the sweeping action and the detector slit parameters [20]. Maintaining the fast rise time of the deflection pulse is critical in maintaining spatially small ion packets at the detector surface, and thus adequate resolution. The overall resolution for the differential impulse-sweeping mode in Fig. 12.3 can be estimated with the following equation developed by Bakker [20] ... 

An important component in any instrument is a set of one or more mechanical slits (or holes) that limit the spatial width of radiation (i) The "source slit" limits the width of the radiation source seen by the sample (ii) the "detector slit" limits the width of the radiation emitted by the sample and sent to the detector. On the one hand, the narrower the slit (or hole), the better the resolution, but on the other hand, the narrower the slit or hole, the weaker the signal seen by the detector. The slits also control the effective bandwidth of the instrument Very narrow slits yield the smallest bandwidth and the best energy or wavelength resolution, but this comes at a price of a weaker signal. 

Misalignment of the instrument. Proper alignment of the instrument is detailed in the company literatme. An experienced operator should align the instrument and check to see that the incident beam intersects the diffractometer axis and the 0° position of the detector slit. 

Vertical divergence error—may be decreased by decreasing the vertical opening of the detector slit. 

Small angle X-ray scattering (SAXS) was measured with a Kratky camera using nickel filtered CuKa radiation. The width of the entrance and detector slits were 20 and 50 pm, respectively. No desmearing procedure was applied to the scattering curves. Absolute measurements were carried out by using a Lupolen standard. 

Detector slit M.. Sollor slit 3° Beam slit 0.0007" Ni filter... 

Detector Slit MR sollor slit 3° Beam slit 0.0007" Ni Filter 4° take off angle Scan at 0.4° 20 per minute Amplifier - 16 coarse, 8.7 fine (gain)... 

Fig. 2. The H2-machine of Moerkerken (1970). The beam is produced from a high pressure source (S) a skimmer (Sk) is placed 10 mm downstream to obtain a nearly monochromatic beam of high intensity the scatter-box (Sb) is surrounded by two pairs of coils to produce a B-field of variable orientation the beam passes through A-, C- and B-fields, which together with the slit D, function as the state selector in the C-field transitions can be induced by a r.f.-coil (RF) the detector slit (D2) is followed by a uhv-Penning detector (P). The numbers below indicate distances in mm.

In Fig. 3 the apparatus is shown with which Stolte (1972) has performed measurements of this type NO molecules were selected with the help of electrostatic sixpole fields, in accordance with their linear Stark effect in strong fields. The source slit of 0 05 mm width has an image formed by the selected NO molecules in the plane of the detector slit which has an experimental width of 1-4 mm f.w.h.m. this width includes all disturbing effects like the magnification factor (about 18), the imperfect linear Stark effect of the NO molecules in the selected state, the finite width of the transmission of the velocity selector (Av/v = 7% f.w.h.m.) in combination with the chromatic lens errors and the directional dependence of the maximum transmitted velocity of the velocity selector. The j = nij = Q = 3/2 state was selected where 1 is the projection of the electronic angular momentum on the molecular axis. The hyperfine structure of NO influences the situation only slightly. 

Here, Cy is defined as the ratio of the corrected anisotropy Ang to the uncorrected one y stands for the lab-angle under which in the plane of the detector slit the full width at half intensity of the primary beam is seen from the scattering centre the wave number k, is calculated in the lab-system, for the primary beam molecules hkl = For NO this angular resolution correction amounts to about 10%, Stolte (1973). 

---