TRIAC Progress Report - KEK

More documents

Recommendations

Info

y using N 2+ beam. For the measurement, FC4 and FC5 installed at entrance and exit of the IH linac respectively were used as well as FC1 and FC2. The transmission of the RFQ is nearly 95 % and that of the IH nearly 100 %, as shown in Fig. 2-17. Energy and energy spread: We measured the output energy T and energy spread ∆T. Figure 2-18 shows the output energy spectra measured at six operating modes, which are described later. The IH-tank4 energy agrees well with a designed one, 1.053 MeV/nucleon. In Table 2-5, the measured T and ∆T values are compared with the calculated values in parentheses. ∆T is defined by 2-rms of the spectrum containing 90% ions. The measured energy spreads are smaller than calculated one except for the RFQ mode and variable modes. Fig. 2-18. Energy spectra for six operating modes Table 2-5. Energy and its spread for six operating modes. Numbers in parentheses are from calculations. The results summarized here were obtained before frequency modifications Different accelerating modes: The linac is operated at different accelerating modes to change the output energy. For example, the IH-tank2 energy in Table 2-5 was obtained 24
y turning off the supply of RF power for the tank3 and tank4, and a variable energy by adjusting the RF power voltage and phase in tank4. Deceleration test of the RFQ beam was conducted by using the IH-tank1, in order to extend the variable-energy range. In the experiment, He + beam was injected at a decelerating phase of 135 o of the IH-tank1, and the output energy and its spread were measured as a function of the IH-tank1 RF voltage. Figure 2-19 shows that the minimum energy is 112 keV/nucleon at a normalized voltage of about 1.8. Fig. 2-19. Energy and its spread vs. normalized voltage. RF stability: The RF power sources have an automatic gain and phase control system, in which a feedback signal is picked up from the forward power to the cavity. As for the forward power, voltage variation is within 0.25 %, the phase one within 0.2 o . However, we cannot ignore the voltage and phase variations in the cavity due to the temperature change. We added three feedback systems to compensate the temperature change effect on the RF voltage and phase in the cavity. One is a piston-turner control system for tuning the cavity. The piston tuners are moved automatically so as to minimize the reflected power from the cavity. The control system comprises the circuits for reading the reflected power levels, the tuner driver circuits, and a personal computer. The second is for keeping the cavity RF level constant in long-term by adjusting a control signal (DC voltage) for RF output at a ten-second interval. The third is for constantly keeping the phase difference between different cavities, the test result shows the phase stability is within 0.2 o . We have found the instability of the RF power supplied for SCRFQ. The instability is associated with two components of voltage fluctuation: one is caused randomly in a few minutes (slow component) and another is by electronic noises synchronized with AC line (50 Hz component). The slow and 50 Hz components of the cavity voltage fluctuation are shown by two red curves (one is in the inset) in Fig. 2-20, and the magnitude of them corresponds to 20 % and 8 % of the nominal cavity voltage, 25
Page 1 and 2: TRIAC Progress Report TRIAC collabo
Page 3 and 4: i KEK Progress Report 2011-1 June 2
Page 5 and 6: PREFACE The Tokai Radioactive Ion A
Page 7 and 8: 1. Introduction Following the succe
Page 9 and 10: maximum available beam power for th
Page 11 and 12: container of ion source and uranyl
Page 13 and 14: gaseous and volatile elements (e.g.
Page 15 and 16: = 10.6 m) were 4.5 %, that for 146
Page 17 and 18: with different plasma volumes [2-6]
Page 19 and 20: ECR plasma: We used natural helium
Page 21 and 22: higher efficiency for gaseous eleme
Page 23 and 24: The asymmetric component representi
Page 25 and 26: ut differs from the electron-loss p
Page 27 and 28: consumption in the cavity is less t
Page 29: measured with Faraday cups, FC1, FC
Page 33 and 34: Encouraged by the new finding, as t
Page 35: 2-4-4. Development of superconducti
Page 40 and 41: accelerating the radioactive ion be
Page 42 and 43: Fig. 2-29. Photos of the pre-bunche
Page 44 and 45: For the proposed experiment, the po
Page 46: a diagonal direction. The monitors
Page 49: charge state of xenon ions by using
Page 52 and 53: electrode as shown in Fig. 2-40) sh
Page 54 and 55: CO2 (10 %) and 16 kPa, respectively
Page 56 and 57: Although the gain shift of THGEM#3
Page 58 and 59: 3. Experiments at the TRIAC Since t
Page 60 and 61: Fig. 3-1. Schematic view of the det
Page 62 and 63: -element abundances up to the third
Page 64: higher reliability of the experimen
Page 67 and 68: GEM-MSTPC among the accumulated dat
Page 69 and 70: upstream of the pre-buncher, avoidi
Page 72 and 73: The process of nuclear polarization
Page 74 and 75: annealed platinum foil (stopper foi
Page 78 and 79: the observed CP-violating phenomena
Page 80 and 81:
offline data analysis, about 1-Mega
Page 82 and 83:
Secondary 9 Li ions extracted from
Page 84 and 85:
Fig.3-24. γ ray energy spectra coi
Page 86 and 87:
In the experiments of RNB-J02/03 (S
Page 88 and 89:
atio), a diffusion coefficient was
Page 91 and 92:
Although the data for β-LiAl and
Page 93 and 94:
In the experiment of RNB-K06 ((Spok
Page 95 and 96:
difference spectra, more specifical
Page 97 and 98:
Mass, which is one of the most fund
Page 99:
gamma rays. 111 In, which decays to
show all

TRIAC Progress Report - KEK

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?