Daystar Quantum H-alpha Solar Filter - SE Grade

Daystar Quantum SE: Digitally Controlled H-alpha Observation

The Quantum SE (Standard Edition) grade is designed for most amateur and some academic applications. The Quantum SE uses an internal microprocessor and a heated Fabry-Perot etalon to maintain its target wavelength with a thermal stability of ±0.5°C. The LCD shows the wavelength currently being transmitted, accurate to 0.1Å.

Designed for field reliability, the filter operates on a 10-30VDC input, making it fully compatible with standard 12V field batteries. For use at a permanent pier or at home, a universal 100-240VAC power supply is included.

Prominence (0.7-0.9Å) vs. Chromosphere (0.3-0.5Å)

The Quantum SE comes in two bandpasses. Exact filter bandpass will vary based on final telescope application, and observers can choose by their observing goals.

• 0.7-0.9Å (Prominence): Choose the Prominence model for more and wider prominences with a little surface; 0.7Å filters reveal prominences in high contrast and occasionally surface texture.
• 0.3-0.5Å (Chromosphere): Choose the Chromosphere model for more surface contrast and narrower prominences; 0.4Å filters reveal excellent surface contrast and fine chromosphere detail, with filaments clearly depicted.

The Quantum SE vs. PE Grade Distinction

Daystar makes its Quantum filters in two grades:

• Quantum SE (Standard Edition): SE grade filters are designed for most amateur and some academic applications, and meet the critical Daystar quality control criteria applicable in all visual and some photographic environments.
• Quantum PE (Professional Edition): The PE grade is designed for professional research studies and applications in which precision homogeneity and onband transmittance values across the substrate surface are required, with additional quality control steps and additional fabrication and testing time.

How the Fabry-Perot Etalon Works at F/30

The heart of the Quantum filter is a Fabry-Perot etalon, an optical component that uses interference to transmit a very narrow band of light. The wavelength it transmits is dependent on its temperature and the angle at which light passes through it. The Quantum's electronics precisely heat the etalon to tune it to the 6562.8Å H-alpha line.

The angle of incidence is equally critical. Light reaching the etalon at an angle shifts the transmitted wavelength, so the filter needs a slow F/27-F/40 beam, preferably F/30. Operating the filter at focal ratios less than F/30 will result in increased bandpass, for example 0.5Å will become 0.8Å on faster configurations.

Telescope Setup: F/27-F/40, ERF, and Mounting Plate Requirements

Install the filter on a telescope operating at F/27-F/40 (preferably F/30) with an appropriate ERF (Energy Rejection Filter). Most telescopes reach this with a telecentric barlow or, on an SCT, an off-axis aperture reducing ERF.

Install it mounted gold side towards the Sun and red side towards the eye. The correct mounting plate is needed (plates are not in the box):

• Refractors: Refractor owners must use a flat plate mounted on the gold side of the filter.
• SCTs (with off-axis ERF): SCT owners must use the 1.9° wedge plate mounted on the gold side of the filter, with the ERF off-axis hole positioned down and the Quantum LCD readout facing up. Use of the wrong plate will result in off-band transmission.

Controller Interface: 0.1Å Readout and ±1.0Å Wing Shift Tuning

On power up, the LCD shows a startup message with the bandpass and SE or PE grade, then the wavelength currently being transmitted. As it heats up, you can watch the wavelength climb toward the H-alpha line at 6562.8Å. The status light remains yellow during this warm-up period.

Once the filter reaches its target temperature, it waits approximately 8 minutes so the heat can radiate completely through the optics. The light then turns green, indicating the filter is on-band and ready for observation. To study Doppler-shifted events, you can use the red (up) and blue (down) buttons to tune the center wavelength by up to 1.0Å in either direction. Pressing a button shows the new target wavelength, and the filter will adjust and re-stabilize, with the light turning yellow until it is on-band at the new target.

Power System: 12VDC Field Operation with a 100-240VAC Adapter

The Quantum SE is designed for both field and observatory use. It accepts a wide power input range of 10-30VDC through a standard 5.5 x 2.1mm jack, drawing a typical 10W of power at 12V. Power options are the AC adapter, alligator clips or a cigarette lighter cord (the last two not included), and it is operational with a European 24VDC automotive cigarette lighter.

For use with mains power, a 100-240VAC, 50-60Hz adapter is included. It comes with user-interchangeable US, Euro, UK and Australian plugs. Protection covers overvoltage, overcurrent and overtemperature, and the unit is fully operational with reverse polarity.

RS232 Port and Quantum Control Software

The Quantum SE has an RS232 computer interface for filter status and offset control. By connecting the filter to a Windows PC, you can use Daystar's free Quantum Control software to monitor the filter's status and adjust its wavelength tuning directly from your screen.

The Quantum serial protocol manual is also available for users writing their own control software.

Thermal Management: Operating from 0°C to +40°C

The Quantum SE is rated for 0°C to +40°C, 20-80% humidity non-condensing. The filter will not operate on band at temperatures above the one listed on its serial number label, which is designed to be above ambient room temperature, and using it above 100°F can make it exceed its desired operating temperature. The etalon is tuned by heating it above the ambient temperature; it relies on passive cooling to reach temperatures lower than its on-band H-alpha setting.

This has a practical consequence for blue wing shifting. Full 1Å blue wing shift is only possible if the ambient temperature is more than 17°F below the temperature noted on the filter, since the filter must cool 17°F to drop 1Å. On very hot days, the ambient temperature may be too high for the filter to cool sufficiently to reach the lowest target wavelengths. In such cases, the LCD readout will not reach the desired target, and the status light will remain yellow. This doesn't alter the operation of the filter; the ambient temperature is just too high to shift that far.

Physical & Optical Specs: 32mm Aperture and 10-Year Warranty

Daystar's Quantum housing measures 76mm in diameter and 43mm long (56mm with filter mounting plates) and weighs approximately 453 g (1.00 lb). The clear and usable aperture is 32mm, with bandwidth measured over the 19mm central aperture. Off-band rejection is an average optical density greater than 6.0 from X-ray to beyond 2.0 microns, and air-glass interfaces are anti-reflection coated.

Daystar warrants its filters free of optical, electrical or mechanical defect for 10 years. Keep the filter in a cool, dry, climate controlled environment when not in use; users in hot, humid environments should store it in an air conditioned space and/or a sealed case, and desiccant is recommended. There are no user serviceable parts: do not open the optical or electronic housings.

A Step-by-Step Guide to Your First Session

Setting up the Quantum SE is straightforward. Follow these steps for a successful first observation:

1. Install Safely: Use an appropriate Energy Rejection Filter (ERF) and set up the telescope at F/27 to F/40 (preferably F/30). Mount the filter gold side towards the Sun and red side towards the eye, with a flat plate for a refractor or the 1.9° wedge plate for an SCT. Take precautions when pointing the telescope without the filter in place, and do not leave the solar telescope unattended in a public place where users might remove the filter.
2. Power On: Connect the filter to a 12VDC source or the included AC adapter. The status light will turn yellow, and the LCD will show a wavelength lower than 6562.8Å.
3. Wait for Green: The filter will now heat up. You can watch the wavelength value climb on the LCD. Once it reaches the 6562.8Å target, the unit waits approximately 8 minutes. After this delay, the light will turn green.
4. Observe: With the green light on, the filter is on band and you can observe.
5. Use Wing Shift: To explore Doppler effects in active regions, use the red and blue buttons to shift the target wavelength. The light will turn yellow as the filter retunes and will turn green again after the 8-minute stabilization at the new wavelength.