7 papers · 1 filter
Building confidence in state-of-the-art ab initio calculations of the density virial coefficients B and C of helium-4: Part 2. Direct evaluation by high accuracy experimental data using RIGT
Haiyang Zhang, Wenjing Liu, Xiangjie Kong +4
In our previous work [1], using indirect evaluation methods we concluded that the uncertainties of the second and the third density virial coefficient, B and C, of helium-4 at 5 K…
Building confidence in state-of-the-art ab initio calculations of the density virial coefficients of B and C of helium-4: Part 1. Indirect evaluation methods using the results of SPRIGT
Haiyang Zhang, Bo Gao, Mark Plimmer +1
In this work, we propose indirect evaluation methods to check the accuracy and the uncertainty of ab initio calculated virial coefficients. To this end, we have used single-pressur…
Active suppression of temperature oscillation from a pulse-tube cryocooler in a cryogen-free cryostat: Part 2. Experimental realization
Changzhao Pan, Jiangfeng Hu, Haiyang Zhang +9
A cryogen-free cryostat cooled by a closed cycle cryocooler is compact, can provide uninterrupted long-term operation (up to ten thousand hours) and is suited to temperatures from…
Active suppression of temperature oscillation from a pulse-tube cryocooler in a cryogen-free cryostat: Part 1. Simulation modeling from thermal response characteristics
Changzhao Pan, Bo Gao, Yaonan Song +9
A cryogen-free cryostat cooled using a 4 K commercial GM or pulse tube cryocooler (PTC) displays temperature oscillations caused by the intrinsic working principle of the regenerat…
Realization of ppm level pressure stability for primary thermometry using a primary piston gauge
Bo Gao, Hui Chen, Dongxu Han +8
To achieve an uncertainty of 0.25 mK in single-pressure refractive-index gas thermometry (SPRIGT), the relative pressure variation of He-4 gas in the range 30 kPa to 90 kPa, should…
Resonance frequency measurement with accuracy and stability at the 10-12 level in a copper microwave cavity below 26 K by experimental optimization
Haiyang Zhang, Bo Gao, Wenjing Liu +4
Single pressure refractive index gas thermometry (SPRIGT) is a novel primary thermometry, jointly developed by TIPC of CAS in China and LNE-Cnam in France. To realize a competitive…