  The High Energy Photon Source (HEPS), is the first fourth-generation storage
ring light source being built in the suburb of Beijing, China. The storage ring
was designed with the emittance lower than 60 pm.rad with a circumference of
1.36 km and beam energy of 6 GeV. Its injector contains a 500 MeV S-band Linac
and a 454 m booster which was designed as an accumulator at the extraction
energy. In the energy ramping control design of HEPS booster, the ramping
process was programed to be able to stop and stay at any energy between the
injection energy and the extraction energy. This feature enables us to conduct
energy-dependent machine studies and ramping curve optimization. The beam
commissioning of HEPS Linac finished in June, 2023. And the beam commissioning
of booster started in the end of July, 2023. In November 17, main target values
proposed in the preliminary design report has been reached. The high-level
applications (HLAs) are essential tools for beam commissioning. The development
of HLAs, which are based on the framework named Python accelerator physics
application set (Pyapas), started in the end of 2021. The HEPS physics team
spent more than one year to develop and test the HLAs to meet the requirements
of beam commissioning of the booster. Thanks to the modular design, the
principle based on physical quantities, and the ability of running simulation
models online from the Pyapas, the development efficiency and reliability of
the HLAs have been greatly improved. In particular, the principle based on
physical quantities allows us to control the beam more intuitively.
