Kavanagh for his great help in the design, planning and execution of the experiment. The number of electromagnetic decays was measured by counting the number of 9Be recoils with the appropriate energy. The branching ratio is therefore the ratio of the number of detected 9Be hits to the number of 9Be.
The reaction rate was measured by counting the gamma decay of the Be. • The adjustment was complicated by the interaction of several adjustments and by the high accuracy required (moving vertically off center by 0. The pulse from the detector was amplified (as shown in the block diagram, Figure 1) by a fast amplifier system, cut to a width of 20 nsec through a shorted length of 93 n cable, and fed to both a co- The biased amplifier also stretched the pulses for storage on the vertical side of the two-dimensional pulse height analyzer.
When the coincidence gates were open, the two-dimensional analyzer stored the heights of the ion and alpha pulses. 5 MeV, the number of pulses fired by the ion side of the coincidence mixer, the number of pulses fired by the alpha side, and the number of coincidence pulses.
ANALYSIS OF RESULTS
2 • Because the ground state randomness was measured over a 6° range every day, the effect of this small alpha angle error on efficiency was known. The fraction of recoil ions in the excited state in the observed charge state (2+ or 4+) is c*, and de. To determine the charge state ratio of Be ions emerging from a boron foil, an elastic scattering experiment was performed on boron-low Be foils.
The charge-state ratios of these measurements at 1. 1965) measured the charge-state ratios at higher energies. Another source of momentum .width was kinematic or dE/d9 broadening, including the extra width caused by deflection of gamma emission from the recoil ions in the magnet's geometric aperture. The final source was the longitudinal component of the momentum of the emitted gamma ray.
However, measurements on the base group profile shape showed a width of up to. With all terms of equation 3) now measured or calculated, the data were combined as follows.
DISCUSSION
18 keV obtained from the measured bandwidth divided by the branching ratio is consistent with the measured upper limit, r < 1 keV (Gossett 1955). The total width is greater than the 1/4 keV value predicted by the alpha model (Henley . 1960) (see Appendix III).
BORON FOILS
Evaporation should continue until enough or all of the unalloyed boron has evaporated. When all the unalloyed pine evaporates, the color of the boat becomes lighter, bluer and more uniform. 1£ the foils develop cracks as they float away, reducing the rate at which the water level rises.
The composition of the foils was measured by counting elastically scattered 1-MeV protons at elab = 150° with a 27-cm double-focus spectrometer. Since the difference in the various impurities was too small to affect the provision of the branching ratio, only the boron and carbon content of the foils used in the experiment were measured. BERYLLIUM'S CHARGE-STATE RELATIONSHIP Since only two of the charge states are 9 Be.
To analyze the data, a method was used that compared the shapes of the different recoil peaks. However, this simple procedure only allows calculation of the errors from count statistics, which are only around 0. Therefore, the more complicated method was used, as it gave a better indication of the error in the experiment.
The number of nucleons with p shell is n, T is the isotopic spin, J is the total angular momentum, MT is the projection of the isotopic spin ( (N - Z) /2 a is the coefficient in. For parameters from average values, different interaction radii for the decomposition of intermediate levels were used in the calculations to show the sensitivity of the calculations to changes in this parameter.A re-examination of the original data revealed an error in the calculation affecting the quoted values for the widths of l
All symbols beginning with B refer to calibration velocity measurements (counting Be 9+++ -a ) made at the beginning. E - All symbols beginning with E refer to calibration randomness rate measurements made at the end of the run. A - Run length was measured by counting the number of alphas with energies above about 6.5 MeV.
When the calibration was not checked at the end of the run, the calibration error was considered to be 1. He (per unit beam charge) counted through counter 8 when the magnetic current was adjusted so that particles of the same stiffness fell on counter 8.
PLAN OF EXPERIMENT
ENERGY(MEV)
A graph of the output of the two-dimensional analyzer, or a Be - a 2, performed on target number i. The magnet was set in such a way that only ions with EM/Z2.
ION ENERGY (MEY)
Coincidences within the 9Be peak from seven runs (21,540 µ.C beam) in Target 4 are summarized and plotted against alpha energy.
ALPHA ENERGY(MEV)
The lines at the top of the figure show where the leading edge of the tips for the various elements should be placed (See pp. 3 and 21.).
FLUXMETER CURRENT
The graph shows the number of counts (corrected with the counter correction factors in Table 9) for each observed charge state (2+, 3+ and 4+) plotted against the 9Be ion energy measured by the magnetic spectrometer. The graph shows the number of counts (corrected with the counter correction factors in Table 9) for each observed charge state (l+, 2+, 3+ and 4+) plotted against 9.
