## 1 Introduction
He clearly stated that plasma has an absorbing and reflecting effect on electromagnetic waves, introducing the concept of plasma stealth [9]. In 1993, [PERSON] et al. studied the refraction, reflection and absorption of electromagnetic waves by plasma sheaths and reported equations for the estimation of reflected and absorbed power [3]. In 2007, [PERSON] et al. studied the effect of plasma with a non-uniform distribution of electron density on the reflection properties of electromagnetic waves [12]. In 2016, [PERSON] et al. further carried out systematic numerical simulations of the composite stealth properties of plasma and wave absorbing materials in their monograph, and optimized their design as well [13]. In 2015, [PERSON] et al. used a 3D barrel model to analyze the plasma stealth of aircraft intakes, but this method could only achieve the goal of stealth in the low frequency band [14]. In 2017, [PERSON] et al. designed a collisional low-pressure plasma in an arrayed structure and measured the radar cross-section of a covered metallic surface. However, their study mainly focused on the X-band and required a constraint layer to achieve the desired results using this approach [15]. In 2018, [PERSON] et al. conducted electromagnetic wave absorption studies using plasma channels formed by femtosecond lasers, but the results of this study could not be directly applied to vehicle stealth [16]. While these studies have contributed valuable insights, there remain challenges in achieving effective plasma stealth across a broader frequency range and in practical applications. Recognizing these limitations, further innovation is necessary to develop more versatile and efficient plasma stealth solutions. This paper presents the design of a novel low-pressure plasma generator, which employs original high-curvature-radius spiked tungsten structure electrodes. It also uses an NHWY10K-0.5 high-frequency switching power supply and high-purity argon gas as the working atmosphere, to form a stable glow discharge plasma. The surface structure of the tungsten electrodes, formed through a hydrothermal reaction, featured high-curvature-radius spikes that enhanced field emission characteristics. The generator's chamber, made from lightweight quartz, was adaptable to various working conditions and was used with a custom-designed Langmuir double probe system for precise plasma density measurements, thereby reducing the cost of plasma generation and diagnostics. This study compared the plasma density produced by box-type iron-nickel alloy electrodes and tungsten electrodes under different conditions. The experimental results indicated that the plasma density generated by the tungsten electrode elements reached up to 7.79 \(\times\) 10\({}^{11}\) cm\({}^{-3}\) under low current conditions, which was 88.2% higher than that of traditional plasma elements and capable of withstanding a broader current range. The study also achieved for the first time an ultra-high-density, large-area, low-pressure cold plasma with a density of up to 1.15 \(\times\) 10\({}^{12}\) cm\({}^{-3}\), surpassing similar studies by more than an order of magnitude [17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27; 28] as shown in Table 1.  
Regarding the parameters of the input power supply, the cold plasma prepared in this study needs to achieve coverage of the equipment to be concealed in electromagnetic wave-absorbing radar stealth applications. In practical operation, the power used by the input supply is strongly correlated with the total volume of the plasma (corresponding to the total area per unit thickness). If the plasma volume is larger (corresponding to a larger area per unit thickness), the power requirements will be higher. Another advantage of this