helium-3 - 2025 ACF Regionals

Question

In a paper about exchange effects in this isotope’s body-centered cubic solid phase, J. H. Hetherington added his cat as a coauthor under the pen name F. D. C. Willard. For 10 points each:

[10m] Name this lighter of the two isotopes used in a standard dilution refrigerator. Tritium undergoes beta-minus decay to generate this isotope.

ANSWER: helium-3 [or He-3; prompt on helium or He]

[10e] Because helium-3 atoms are fermions, they do not readily exhibit this low-temperature property in which a substance exhibits zero viscosity.

ANSWER: superfluidity [or word forms]

[10h] With Ginzburg and Leggett, this physicist won the 2003 Nobel Prize for theories on superfluid helium-3. This Russian physicist and Khalatnikov expanded Landau’s theory of Fermi liquids to model low-temperature helium-3.

ANSWER: Alexei Abrikosov

<MY, Physics>

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Summary


Florida	2025-02-01	Y	2	15.00	100%	50%	0%
Great Lakes	2025-02-01	Y	6	10.00	100%	0%	0%
Lower Mid-Atlantic	2025-02-01	Y	6	8.33	83%	0%	0%
Midwest	2025-02-01	Y	6	13.33	100%	33%	0%
North	2025-02-01	Y	3	16.67	100%	33%	33%
Northeast	2025-02-01	Y	5	14.00	80%	40%	20%
Overflow	2025-02-01	Y	5	12.00	100%	20%	0%
Pacific Northwest	2025-02-01	Y	2	10.00	100%	0%	0%
South Central	2025-02-01	Y	2	10.00	100%	0%	0%
Southeast	2025-02-01	Y	4	7.50	75%	0%	0%
UK	2025-02-01	Y	10	11.00	90%	20%	0%
Upper Mid-Atlantic	2025-02-01	Y	8	11.25	88%	13%	13%
Upstate NY	2025-02-01	Y	3	6.67	67%	0%	0%

Data


South Carolina	UNC C	0	10	0	10
Chicago B	Chicago D	0	10	0	10
Iowa	Northwestern B	0	10	0	10
Northwestern A	Purdue	10	10	0	20
Cambridge C	Durham	0	10	0	10
Cambridge B	Imperial B	0	10	0	10
LSE	Warwick B	0	10	0	10
George Washington A	Columbia C	0	0	0	0
Maryland A	George Washington B	0	10	0	10
Duke	Wake Forest	0	10	0	10
Liberty A	Liberty C	0	10	0	10
Virginia Tech A	Liberty B	0	10	0	10
UNC D	UNC B	0	0	0	0
Virginia A	William & Mary	0	10	0	10
Chicago C	Chicago A	0	10	0	10
Missoui S&T	Illinois B	0	10	0	10
Georgetown A	Notre Dame B	0	10	0	10
Georgetown B	Notre Dame A	0	10	0	10
Stanford B	Notre Dame C	0	10	0	10
UW B	Alberta	0	10	0	10
UBC	UW A	0	10	0	10
Southampton A	Bristol	0	10	0	10
Cambridge A	Southampton B	10	10	0	20
Cambridge E	NYU C	0	0	0	0
Sheffield	Oxford A	0	10	0	10
Penn A	NYU A	10	10	0	20
ESF A	Cornell C	0	0	0	0
Florida B	Florida State A	10	10	0	20
Florida A	UCF B	0	10	0	10
Carnegie Mellon A	Case Western B	0	10	0	10
Michigan B	Case Western A	0	10	0	10
Michigan State	Kenyon	0	10	0	10
Michigan A	Carnegie Mellon B	0	10	0	10
Michigan C	Michigan D	0	10	0	10
Ohio State A	Ohio State B	0	10	0	10
Illinois C	Indiana A	10	10	0	20
Missouri	Illinois A	0	10	0	10
WashU B	WashU A	10	10	0	20
Iowa State	Wisconsin B	10	10	10	30
Minnesota B	Wisconsin A	0	10	0	10
Winona State	Carleton	0	10	0	10
BU	Dartmouth A	10	10	10	30
Tufts A	Brandeis B	10	10	0	20
Brandeis A	Brown A	0	0	0	0
Harvard A	MIT A	0	10	0	10
Harvard B	UMass Boston	0	10	0	10
ASU	Texas A	0	10	0	10
Texas B	TAMU	0	10	0	10
Alabama A	Georgia Tech A	0	10	0	10
Louisville A	Georgia Tech D	0	10	0	10
Georgia Tech B	Tennessee A	0	10	0	10
Vanderbilt A	Georgia Tech C	0	0	0	0
Oxford B	Manchester	0	10	0	10
Oxford C	Cambridge D	0	10	0	10
Imperial A	Warwick A	10	10	0	20
Rutgers A	Cornell B	0	10	0	10
Vassar A	Haverford A	0	10	0	10
Penn B	Haverford B	0	10	0	10
John Jay College	Columbia B	0	10	10	20
Yale A	Johns Hopkins A	0	10	0	10
Binghamton A	RIT A	0	10	0	10
Cornell D	RIT B	0	10	0	10