Performance of an Axial Gas Ionization Detector (original) (raw)
Gas detectors for nuclear physics experiments
EPJ Web of Conferences, 2018
In this lecture I will present the operation principle and the different kinds of gas detecting systems for charged particles employed in high-energy and low-energy physics environments, with particular focus on the requirements of nuclear physics experiments with low-energy Radioactive Ion Beams (RIBs). I will show in more details an example of gas detector used at the RIB in-flight facility EXOTIC, for the ion beam tracking and for time of flight measurements. Finally, I will discuss the use of an active target in nuclear physics experiments with RIBs together with some key improvements of first generation devices required for facing the challenges of more intense RIBs.
The PRIME Lab gas ionization detector
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 1994
A gas ionization detection system was built for optimal identification of AMS radionuclides, in particular "Be and 36Cl. For 36CI, a combination of 1) the difference in arrival times for electrons at two anode plates and 2) a novel split anode plate has led to a reduction in misidentified 36S. A peak-stabilizing routine incorporated in the data acquisition system has allowed us to run at higher counting rates. Changing to propane gas has reduced random signal amplitude shifts.
Commissioning of a portable ionization chamber at high counting rate using heavy ion beams
Journal of Radioanalytical and Nuclear Chemistry, 2019
A fast ionization chamber with a high counting rate was commissioned at the 8 MV tandem accelerator complex of Kyushu University in Japan. Heavy ion beams consisting of 12 C and 16 O with E beam = 36 MeV were used to investigate the detector performance. By using various beam intensities ranging from 10 3 to 10 6 particles per second (pps), the maximum counting rate of the ion counter was measured to be about 8 × 10 5 pps. The detector performance under different gases was also investigated using two common gases in the ionization chamber: isobutane and P-10 gases. The results show that the negative effects due to pileups, which are often observed at high counting rates, can be greatly reduced when P-10 gas is used.
High-rate axial-field ionization chamber for particle identification of radioactive beams
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2016
The design, construction and performance characteristics of a simple axial-field ionization chamber suitable for identifying ions in a radioactive beam are presented. Optimized for use with low-energy radioactive beams (< 5 MeV/A) the detector presents only three 0.5 µm/cm 2 foils to the beam in addition to the detector gas. A fast charge sensitive amplifier (CSA) integrated into the detector design is also described. Coupling this fast CSA to the axial field ionization chamber produces an output pulse with a risetime of 60-70 ns and a fall time of 100 ns, making the detector capable of sustaining a relatively high rate. Tests with an α source establish the detector energy resolution as ∼8 % for an energy deposit of ∼3.5 MeV. The energy resolution with beams of 2.5 and 4.0 MeV/A 39 K ions and the dependence of the energy resolution on beam intensity is measured. At an instantaneous rate of 3 x 10 5 ions/s the energy resolution has degraded to 14% with a pileup of 12%. The good energy resolution of this detector at rates up to 3 x 10 5 ions/s makes it an effective tool in the characterization of low-energy radioactive beams.
IOSR Journal of Applied Physics, 2014
This work explores theoretically the possibility of using a simple pulse mode parallel plate gas ionization chamber, having no Frisch grid, both for energy estimation and Z-identification of moderate energy light heavy ions. A mathematical expression for the energy of a heavy ion that enters into the ionization chamber through the cathode window and gets stopped in the sensitive volume is derived. An expression for a quantity similar to the range of the heavy ion is also derived. The plot of energy against this quantity is expected to give an opportunity to use a simple pulse mode parallel plate gas ionization chamber, without Frisch grid, as a light heavy Z-identifier. This work is based on the measurement of the electron collection pulse height and two other heights that the electron collection pulse reaches at two pre-calculated instants of time during the pulse rise time. A 'preset pulse clipper', the basic principle of which was proposed in a previous paper, may be used to measure the heights. Measuring heights-without using the 'preset pulse clipper'-by means of digital sampling and software based processing techniques may be possible if it be possible to determine the start time of the digitized pulse. One possible method for determining the start time of the digitized pulse is evaluated. The simulated plots, which represent the expected identification capability of this method, are made considering all the phenomena relevantly associated from physical point of view.
Design and test of a versatile gamma ionization chamber for gamma field monitoring_(LYON_1994)
Gamma ionization chambers are widely used in the field of nuclear technology. They are especially employed for gamma environmental monitoring around nuclear plants. In this work, we have performed a thorough study dealing with the main physical processes that occur in gamma ionization chambers during operation. To this respect, we have developed computer programs which allow us to estimate the chamber sensitivity and its saturation characteristics. This set of programs has been used to design a 0.5 liter Versatile Gamma Ionization Chamber (VGIC) for experimental purposes. The constructed chamber is characterized by a moderate sensitivity of 1.57 10 -10 A/Rem/h and by a rather large operating range ( 10 mRem/h -10 4 Rem/h ), when it is filled with argon at a pressure of 5 bars. An acceptable agreement between the theoretical predictions and the experimental results is obtained.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1995
The ionization efficiencies of a cylindrical ionization chamber have been calculated using a Monte Carlo electron-photon transport code. The results agreed well with experimental values for radioactive gases. The present calculational procedure can be applied to the estimation of ionization efficiencies for radioactive gases, such as the short half-lived nuclides and positron emitters, which have been difficult to estimate through experimental calibrations. It can also be applied to evaluations of efficiencies in gases other than air. This paper describes the calculation method and results, and also presents the effects of shape and volume variations of the ionization chamber.
Pressurized ion chamber for low energy radiation monitoring
Radiation Measurements, 1997
Ion chambers that can respond to gamma energies as low as 35 keV have been developed for environmental and area monitoring for low energy X-ray background at the rotating anode X-ray generator facility and other accelerators at CAT, Indore. They are expected to measure exposure levels ranging from 10 ~r/h to 100 mr/h. These chambers have an all-welded aluminium construction and pressurized nitrogen filling. Explosion welded SS-AI clad material has been used for the welding of SS-to-alumina insulators. Out of the two ion chambers developed, the environmental ion chamber has a 25 1 sensitive volume filled at 85 psi and detects radiation exposure levels from l0 I~r/h to 10 mr/h. The 800 cc area monitor ion chamber filled at 120 psi can be used from 10 mr/h to 10 r/h with a portable survey instrument. These chambers have an energy response between 35 keV and 1.25 MeV that is uniform within + 9%. ~:C~ 1997 Elsevier Science Ltd
Ionization chambers for materials analysis with heavy ion beams
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
The principles of operation for gas ionization counters and the decisive parameters for the energy resolution are described. Examples of ionization chambers used for ion beam analysis are given and the properties and limitations of this detector type are discussed.