Quartz Tuning Forks as Cryogenic Vacuum Gauges

Cooling a Macroscopic Mechanical Oscillator close to its Quantum Ground State

“…Nevertheless, the obtained data show that a pressure of 1 mbar of 4 He should lead to a quality factor reduction by a factor of 2 for a quartz tuning fork at 4 K, which therefore constitutes a cheap (< 1 Euro), compact and rapidly implemented pressure sensor for our purposes that is useful in the range from 0.1 to above 1000 mbar. Similar conclusions with more extensive characterization measurements were reported by another group [HVVT14].…”

Acoustic damping of quartz tuning forks in normal and superfluid He3

“…The interaction of helium fluids with small mechanical resonators has traditionally being studied using vibrating wires, and has led to observations of the quantization of vortices in superfluid 4 He [1,2], nucleation of quantum turbulence [3,4], and Landau critical velocity in superfluid 3 He [5]. Developments in the manufacturing of electronic components and easy access to nanofabrication facilities have brought a plethora of other mechanical devices to helium research, for example quartz tuning forks [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23], micro and nanoelectromechanical devices (MEMS and NEMS) [24][25][26][27][28], optomechanical resonators [29][30][31], and carbon nanotubes [32]. Since the 2000s quartz tuning forks have become an established tool to investigate quantum solids [6] and liquids [7][8][9][10], where they have been used in studies of the viscosity [7], solubility of 4 He- 3 He mixtures [10], Andreev retroreflection of quasiparticle excitations in ...…”

“…The main reasons for the forks' popularity are their high intrinsic quality factor, commercial availability, compact size, and the ease of use. Their working procedures are well documented [8,11,33] and after calibration they can be used as temperature probes [8,12] or pressure gauges [14,15].…”