Sensitive far uv spectrograph with a multispectral element microchannel plate detector for rocket-borne astronomy.

Area of Science:

• Astronomy and Astrophysics
• Space Science
• Spectroscopy

Background:

• Sounding rocket missions present significant environmental challenges for sensitive scientific instrumentation.
• High-resolution spectroscopy in the far ultraviolet (1160-1750 Å) is crucial for studying stellar and planetary atmospheres.
• Previous detection systems lacked the sensitivity required for faint ultraviolet signals.

Purpose of the Study:

• To develop and test an evacuated high-transmission prism spectrograph with a microchannel plate detector for sounding rocket applications.
• To assess the performance and calibration stability of the system under flight conditions.
• To obtain far-ultraviolet spectra of astronomical targets with unprecedented sensitivity.

Main Methods:

• A precision pointing telescope was integrated with an evacuated high-transmission prism spectrograph.
• A microchannel plate (MCP) detector with resistive strip readout was employed for signal detection.
• The spectrograph and detector were maintained at a high vacuum (~10⁻⁶ Torr) until reaching altitude, and MCPs were operated at lower gains with sensitive pulse counting electronics.

Main Results:

• The microchannel plate detector system demonstrated robust performance despite adverse sounding rocket flight conditions.
• Far-ultraviolet spectra (1160-1750 Å) of stellar and planetary objects were successfully acquired.
• Spectral features with fluxes as low as 0.06 photons cm⁻² sec⁻¹ were detectable, indicating high system sensitivity.

Conclusions:

• The developed spectrograph system is suitable for far-ultraviolet astronomical observations from sounding rockets.
• The microchannel plate detector system offers high sensitivity and reliability in space environments.
• The system's performance validates the approach for future ultraviolet space spectroscopy missions.