1 st : Mass Spectrometry on Heavy Molecules with Cryogenic Detectors - status Project Review 2004 PROTEOM 2 nd : Measurement of the Quenching Factors in CaWO 4 with the Mass Spectrometer – a new technique spin off Peter Christ 1

Mass Spectrometry on Heavy Molecules with Cryogenic Detectors - status Outline Proteomics Why cryogenic detectors in MS ? Experimental setup Measurements 2

genomics proteomics - ~ 10 times more proteins than genes - proteins are ‘dynamic’, change with disease … -> medical diagnostics Proteomics subproject of the BMBF Leitprojekt „Proteinanalyse des Menschen“ 3

Cryogenic Detectors - why? 4 (MCP): high mass (low velocity) cryogenic detectors: measure the energy of an impinging particle (independent of velocity) lower detection sensitivity mass independent detection efficiency 100% - large Protein ID (complexes) - medical diagnostics („Biomarker“) - characterisation of synthetic polymers -... possible applications: (SPT, see CRESST)

Experimental Setup - TOF with cooled ion mirror 5 cooled reflector detector ~ 80mK MCP (optional) 77K 4K ion path

Experimental Setup - view inside the lab 6 laser cryostat MALDI ion source cryogenic detector TOF

Experimental Setup - view inside the ADR 7

8 3mm

Measurements - detection sensitivity (insulin) matrix: sinapinic acid method: dried droplet laser shots: approx

Measurements – detection sensitivity (insulin) 10 MCP cryogenic detector direct comparison

Measurements - detection sensitivity (insulin) matrix: DHB method: dried droplet laser shots: approx cryogenic detectorMCP Europ. J. of Mass Spectrom. 10, (2004)

Measurements - first ‘real’ samples 12 blood plasma Matrix: ferulic acid

Summary & Outlook Improvement of the detection sensitivity of insulin by 2 – 3 orders of magnitudes compared to MCP: (< 1amol absolute amount on target) detection sensitivity with larger molecules further detector-development (time resolution) study new applications First measurements on ‚real life‘ samples. Application for a ‚Institutsübergreifende Forschungsinitiative‘ together with the MPI für molekulare Genetik, Berlin 13

Measurement of the Quenching Factors in CaWO 4 with the Mass Spectrometer – a new technique Outline Quenching factor Idea & experimental setup Results 14

Quenching Factor Quenching Factor = light output from nuclear recoil light output from  energy in phonon channel [keV] energy in light channel keV ee ] neutrons / WIMPs electrons,  ´s QF=1 QF>1 15

Measuring the Quenching Factors with neutrons monoenergetic n photomultiplier n CaWO 4 neutron detector TUM, Thomas Jagemann Measured value for oxygen QF is ~ 13 QF values of other nuclei hard to be determined 16

Measuring the Quenching Factors with MS photomultiplier W, Ca, O,... teflon reflector ‚shooting ions onto the crystal‘ 17

Experimental Setup 18 cooled reflector detector ~ 80mK MCP (optional) 77K 4K ion path

Experimental Setup 19 MCP (optional) ion path PM deflection plates

Experimental Setup – selection of ions 20 selection of ions with the deflection plates (CuBe sample)

Experimental Setup – counting the photons 21

Results – reference measurement, 55 Fe (5.9keV X-ray) 22 ~24 pe - / 6keV -> ~4pe - / keV QF = 1

Results – O Ca W ± 0.07 pe ± 0.06 pe ± 0.05 pe - QF(O) = 14.2 QF(Ca) = 26.4QF(W) = 40.5 Ion energy 18keV

Results – quenching factors in CaWO 4 24 Jelena Ninkovic, Thesis (in preparation)

Measuring the QF at low temperatures 25 cooled reflector MCP (optional) 77K 4K ion path deflection plates APD in progress !

Conclusions 26 Measuring of the Quenching Factors with our mass spectrometer works! Consequences of QF(W)  40 for CRESST: WIMPs make W-recoils practically without light kg days CaWO 4 light to phonon ratio energy phonon channel [keV] 90 % of oxygen recoils below upper red line 90 % of tungsten recoils below black line

Conclusions - exclusion plot 27

Future Jelena Ninkovic (quenching factor measurements) Stefan Rutzinger (left in march 2004) Peter Christ personnel Up to the end of this year entirely financed by BMBF Leitprojekt „Proteinanalyse des Menschen“ Application for a ‚Institutsübergreifende Forschungsinitiative‘ with the MPI für molekulare Genetik (Berlin) is on the way money 28