HIAF Accelerator Complex

HIAF is an accelerator complex composed of the Superconducting Linac, the Booster Ring, the High Energy Fragment Separator, and the Spectrometer Ring. The Superconducting Linacis used as the injector with a length of 180 meters, which is equipped with a new-generation 45 GHz, 20 KW superconducting ECR ion source to deliver very high currents of highly charged heavy ions. The Linac can be operated with either continuous wave mode or pulse mode, providing intense heavy-ion beams for low-energy experiments or injecting highly charged ions into the Booster Ring, respectively. The Booster Ring with a circumference of 569 meters and a maximum magnetic rigidity of 34 Tm accumulates and accelerates ion beams. Huge ion number can be injected and stored in the ring under the large phase-space condition of *****. Due to space charge and dynamic vacuum effects, ions stored are launched to high energy very quickly using the fast ramping rate operation. The High Energy Fragment Separator (HFRS) is coupled to the Booster Ring. The HFRS is able to produce unstable ions using heavy-ion projectile fragmentations or in-fight fissions of energetic heavy projectiles, and then separates, identifies and transports the ions of interest for various experiments. With slow extraction of high-energy ions from the Booster Ring, the HFRS is used as a separator and spectrometer. While using fast extracted beams from the Booster Ring, the HFRS injects unstable ions into the Spectrometer Ring for storage-ring based experiments. 

Layout of the accelerator complex of HIAF. The experimental stations related to the Superconducting Linac and Booster Ring are schematically shown schematically.

HIAF Beam Parameters

Typical beam parameters from the Booster Ring are presented in the Table. We can see that very intense heavy-ion beams will be available at HIAF; taking the ion of 238U34+as an example, over 1.0´1011particles can be stored and the maximum energy of 800 MeV/u could be achieved. The intensity shown is obtained by optimizing the charge state of the ion, in other words, it is the highest intensity for the specific isotope. It is worth noting that higher beam energies could be available if needed on a tradeoff of the beam intensities.

Table Typical beam parameters from the Booster Ring. The beam

intensities are given in the unit of particles per pulse (ppp).

Ion species

Energy (GeV/u)

Intensity (ppp)

P

9.3

2.0x1012

18O6+

2.6

6.0x1011

78Kr19+

1.7

3.0x1011

209KBi31+

0.85

1.2x1011

238U34+

0.8

1.0x1011


HIAF Capability

HIAF is characterized by the unprecedented heavy-ion beam intensities, and hence gives us great opportunities to explore the hitherto unknown territories in nuclear chart. The daily production yields for isotopes were calculated using projectile fragmentation, in-flight fission, multi-nucleon transfer, and fusion reactions. The optimized yield for each isotope is presented in the figure, in which the red lines are the boundaries of the known nuclides to date, and the gray lines are the proton and neutron drip-line, respectively. The limits shown are the production rate of one nuclide per day, which enables the “discovery experiments”, i.e. the production and identification of new nuclides. A prolific source of nuclides will be provided at HIAF, and most importantly we could access the proton drip-line nuclides up to uranium and the neutron-rich nuclides far away from the stability line in medium and heavy mass regions. Therefore, HIAF is one of the most powerful facilities in the world to explore the nuclear chart.

The the isotope production yield per day calculated using various reactions. The yields for the benchmark nuclides with double shell closures are given in the inset. The red and gray lines show the boundaries of known nuclides and the drip-lines, respectively. The different colors indicate the production yields in orders of magnitude.