Reportable Segments - Schedule of Reportable Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024	Sep. 30, 2024
Segment Reporting Information [Line Items]
Net Revenues		$ 15,580	$ 25,433	$ 39,965	$ 50,353
Operating (loss) income:		(31,583)	1,363	(31,244)	(7,571)
Identifiable Assets		83,408		83,408		$ 118,953
Operating Segments | Thermal Processing Solutions
Segment Reporting Information [Line Items]
Net Revenues		10,575	17,441	29,259	34,968
Operating (loss) income:		(8,401)	896	(5,528)	1,977
Identifiable Assets		53,282		53,282		68,051
Operating Segments | Semiconductor Fabrication Solutions
Segment Reporting Information [Line Items]
Net Revenues		5,005	7,992	10,706	15,385
Operating (loss) income:		(21,077)	900	(21,435)	(6,943)
Identifiable Assets		23,215		23,215		46,915
Non-Segment Related
Segment Reporting Information [Line Items]
Operating (loss) income:		(2,105)	$ (433)	(4,281)	$ (2,605)
Identifiable Assets	[1]	$ 6,911		$ 6,911		$ 3,987

[1] * Non-segment related assets include cash, fixed assets, and other assets.