Reportable Segments - Schedule of Reportable Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Sep. 30, 2024
Segment Reporting Information [Line Items]
Net Revenues		$ 19,557	$ 26,749	$ 59,522	$ 77,102
Operating (loss) income:		915	816	(30,328)	(6,755)
Identifiable Assets		89,464		89,464		$ 118,953
Operating Segments | Thermal Processing Solutions
Segment Reporting Information [Line Items]
Net Revenues		14,208	18,038	43,467	53,006
Operating (loss) income:		2,907	1,690	(2,620)	3,666
Identifiable Assets		56,734		56,734		68,051
Operating Segments | Semiconductor Fabrication Solutions
Segment Reporting Information [Line Items]
Net Revenues		5,349	8,711	16,055	24,096
Operating (loss) income:		878	1,621	(20,557)	(5,321)
Identifiable Assets		25,315		25,315		46,915
Non-Segment Related
Segment Reporting Information [Line Items]
Operating (loss) income:		(2,870)	$ (2,495)	(7,151)	$ (5,100)
Identifiable Assets	[1]	$ 7,415		$ 7,415		$ 3,987

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