The instruments for the HEP (High Energy Particle) experiments of the GEOTAIL mission, launched in July 1992, consist of 5 spectrometers (LD, BD, MI-1, MI-2 and HI). The LD (Low energy particle Detector) and the BD (Burst Detector) are mainly used to measure electrons, protons, helium and oxygen ions which reflect plasma dynamics in the magnetotail region. On the other hand, MI-1, MI-2 (Medium energy Isotope telescope-1, -2) and HI (High energy Isotope telescope) are used to measure the isotope abundance of solar flare particles and cosmic ray particles which reflect physical conditions of interplanetary space and origin of these particles

The Energetic Particle Spectrometer Hep onboard the Geotail Spacecraft

The combination of γ-ray spectroscopy and charged-particle spectroscopy is a powerful tool for the study of nuclear reactions with beams of nuclei far from stability. This paper presents a new silicon detector array, SHARC, the Silicon Highly-segmented Array for Reactions and Coulex. The array is used at the radioactive-ion-beam facility at TRIUMF (Canada), in conjunction with the TIGRESS γ-ray spectrometer, and is built from custom Si-strip detectors utilising a fully digital readout. SHARC has more than 50% efficiency, approximately 1000-strip segmentation, angular resolutions of Δθ ≈ 1.3 deg and Δ ≈ 3.5 deg, 25–30 keV energy resolution, and thresholds of 200 keV for up to 25 MeV particles. SHARC is now complete, and the experimental program in nuclear astrophysics and nuclear structure has commenced.

http://iopscience.iop.org/article/10.1088/1748-0221/6/02/P02005/pdf

SHARC: Silicon Highly-segmented Array for Reactions and Coulex used in conjunction with the TIGRESS γ-ray spectrometer

The real time monitoring of environmental radiation in the Space-Lab of STS-65 (IML-2: inclination 28.5°, mitude 300 km) has been achieved successfully through the flight by a new silicon detector telescope called “Real time Radiation Monitoring Device” (RRMD). It consists of two 2-dimensional position sensitive silicon detectors and six diode type silicon detectors. In this monitoring, the temporal variation of rates of particle flux, together with the dose equivalent and the LET distribution at three locations in the Space-Lab, were reasonably given in real time. The LET distribution obtained by the RRMD and CR-39 track detectors measured at the same location is in good agreement except at the highest LET region >200 keV/μm and the lowest LET region

Real time measurement of LET distribution in the IML-2 Space-Lab (STS-65)

The design of a magnetic spectrograph of the QDQ type, to be coupled to a 6 MV Van de Graaff accelerator for the analysis with Rutherford backscattering and recoil spectroscopy of surfaces and thin layers, will be shown. Due to the high energy resolution of. the instrument (ΔEE ≈ 2 × 10−4) the depth resolution is determined mainly by energy straggling and the combined effect of angular and lateral straggling, and is close to l monolayer near the surface. The mass discrimination of the spectrograph in combination with the energy dispersion of the detector in the focal plane makes possible the background-free detection of light (1H−19F) atoms recoiling from a heavier substrate. The design of the total setup is such that channeling and channeling plus blocking experiments can be carried out, so that the position of light (or heavy) atoms on or in monocrystalline samples can be measured. The detector in the focal plane is position-sensitive in two dimensions so that with one setting of the spectrograph an energy range of 2% and an angular distribution of 5° (with a resolution of 0.1°) can be measured simultaneously. The opening angle in the energy-dispersive direction is 0.1°. The whole spectrograph, including the scattering chamber, can be rotated over 120° with respect to the beam line. For this purpose a bellows construction is made between the beam line and the scattering chamber, permitting the rotation while maintaining a vacuum of ≈ 10−10 Torr in the chamber.

Design of a magnetic spectrograph for surface, interface and thin-layer analysis

We report on a recently developed large-area position-sensitive silicon detector type with four-corner readout. It consists of a square-shaped ion-implanted resistive anode framed by additional low-resistivity strips with resistances smaller than the anode surface resistance by a factor of two. The detector-position linearity, position resolution and energy resolution were measured with α-particles and accelerated heavy ions. In-beam experimental results reveal a position resolution below 1 mm (FWHM) and a very good non-linearity of less than 1% (rms). The energy resolution determined from 228Th alpha source measurements corresponding to an alpha line energy of 6778 keV is 155 and 68 keV (FWHM) for detectors with geometric areas of 62 mm×62 mm and 20 mm×20 mm, respectively.

Performance evaluation of position-sensitive silicon detectors with four-corner readout

A two-dimensional position sensitive silicon detector (PSSD) with a good linear response, consisting of a square ion-implanted resistive anode with a boundary of an additional resistive-strip electrode, was newly developed. Linearity and resolution for the PSSD were investigated using 40 MeV helium and 95 MeV nitrogen ion beams. The PSSD has an effective area of 45 mm×45 mm, a thickness of 400 μm, a junction capacitance of 500 pF, a surface resistance of the ion-implanted resistive anode of 18 kω□ and a resistance of the strip line of 1.4 kω. The nonlinearities and resolutions (FWHM) of the position were 0.75% and 1.97 mm for 40 MeV helium ions obtained by 6 μs pulse shaping, and 0.47% and 0.71 mm for 95 MeV nitrogen ions obtained by 12 μs pulse shaping, respectively.

New two-dimensional position sensitive silicon detector with good position linearity and resolution

A particle identification technique has been developed combining the use of a position-sensitive silicon detector with a simple magnetic system. Measurements of time of flight, energy loss, total energy, and magnetic rigidity provided the determination of the atomic number, the charge state, and the mass of produced fragments. The resultant resolutions were ΔA = 0.34 (FWHM) for mass number A = 40 and ΔZ = 0.24 (FWHM) for atomic number Z = 20.

Identification of projectile fragments using position sensitive silicon detectors

http://link.springer.com/content/pdf/10.1007/978-94-011-4798-9_122.pdf

Hiroichi Yamaguchi

Papers

New two-dimensional position sensitive silicon detector with good position linearity and resolution

Identification of projectile fragments using position sensitive silicon detectors

Correlation between the AKR and Kp/Dst Indices