2019-06-29 (土) 21:24:25 (1814d)

Beam-line configuration

OEDO project modifies the current beamline which has been operated as "High-Resolution Beam-line" in RIBF, or "SHARAQ" beam line. In March, 2017, new devices of a STQ (Superconducting Triplet Quadrupole magnet) and an RF-deflector have been installed. The most of parts of OEDO beamline were rearranged with existing beamline devices. The commissioning of the OEDO beamline was successfully performed in June, 2017.

The OEDO beamline shares the elements with BigRIPS from F0 to F6. The elements of OEDO after F6 are listed below and the OEDO beamline finally gets connected to the SHARAQ spectrometer.

From the result of the Day0 experiments, where 107Pd, 93Zr, 77,79Se beams around 20-30 MeV/nucleon were produced, the total transmission of 5% to the secondary target position (S0) was obtained with the momentum slit at F1 of +/- 1%, the beam spot size at F3 within 10 mm in diameter.

The transmission dropped mainly at FE8 and FE11. To improve the transmission at FE8, we tested a new optics with 77Se beam with 70 MeV/u down to FE9. The beam transmission was 54% at FE11 and 18% at S0. To improve tranismission to S0 by a factor 3, a new triplet quadrupole magnet needs to be installed.

F0 - F6BigRIPS
FE7Vacuum chamber for beam monitor
D - Q
FE8Dispersive focus
Q - D - QQQ
FE9Dispersive focus for an energy degrader
FE10RF deflector
FE11Achromatic focus
FH12/S0Achromatic focus
SHARAQ spectrometer
S2Focus for measurements of outgoing particles

Intensity estimation for your proposals

Though the energy degraded RI beam production scheme by OEDO is still under development, the beam intensity at the secondary target can be estimated by using the following conditions:

  • Momentum acceptance at F1 : +/- 2%,
  • Spot size at F3 : smaller than 10mm diameter,
  • Angular acceptance at F3 : smaller than 10mrad(H) and 20mrad(V),

With the conditions above, transmission to the secondary target can be estimated to be 18%, which is based on the preliminary result of the Day0 experiment.

You are able to estimate the secondary beam intensity at F3 which satisfies the above conditions #1-3 by using a simulation code such as LISE++. 18% of the value is a rough indication of beam intensity at S0.

Because parameters to degrade the beam energy strongly depend on each isotope and the desired beam energy, we cannot fully assure the intensity at S0. If you are interested in the development of OEDO-SHARAQ beam line and wish to make experiments, we always welcome research collaborations with you.

This web page will be updated accompanying with development of OEDO. Before preparing the experimental proposals, we would like you to contact the scientific coordinator of OEDO, Prof. N.Imai (

Spectrometer SHARAQ for outgoing nuclei

The SHARAQ is a QQDQD spectometer with the dP/P= 1/15000 resolution. It was installed before the OEDO is implemented. By employing the first half section of the SHARAQ named the QQD mode, the wide momentum acceptance of +/- 3% and the reasonable resolution of dP/P=1/3000 can be achieved. The detailed can be found at the SHARAQ spectrometer.

Recoil Particle Detector TiNA

The summarized slide can be found here filetina_tec_public.pdf

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